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NASA Spec3 Contstructor's Guide
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NASA Spec3 Constructors’ Guide

By: Taylor Johnson and Sean O’Hara, some photos by Ross Shull - Last Updated 1/5/2024

Please reference the live version of the document for the latest updates: https://docs.google.com/document/d/e/2PACX-1vQDsUb6faeC-OvrCrpPg6MaJGPpTW7kPMsfBBi6LFxs4vHUaVADMxMHpJcnftDR726WNqH5fueX5UoU/pub

PLEASE READ THE OFFICIAL CLASS RULES BEFORE DOING ANYTHING ELSE: https://members.drivenasa.com/rules/spec3_rules.pdf

Welcome to the NASA Spec3 Constructors’ Guide. Please reference the official NASA Spec3 Rules for any part specific compliance issues. This guide serves to walk you through the “process” of building a NASA Spec3 race car. This does NOT replace the official rules of the series. Please double check the CCR and Spec3 rules before acting on anything in this guide.

This document’s purpose is to share useful information related to building a SPEC3 race car to compete in the racing class of the same name of the National Auto Sport Association. Auto racing is dangerous and this guide is not a definitive set of steps on how to be safe or how to drive or build in a responsible manner. Ultimately the final decisions are upon the builder and driver and due care should be taken at all steps.

Official Website: https://drivenasa.com/road-racing/spec3/ 

Facebook Media Page: https://www.facebook.com/NASASpec3

Instagram: https://www.instagram.com/nasaspec3/

FB Discussion Group: https://www.facebook.com/groups/spec3

Sanctioning Body: https://drivenasa.com/ 

Parts List https://docs.google.com/spreadsheets/d/1OlOMni51nbqwuyZUN7aE8V9y77sN1THtBnFW9rwHqmM/edit?usp=sharing

Logos/Files for decals: https://drive.google.com/drive/folders/1duTOMlrXnQavBIuO1j21PQbNSKkSSFXb?usp=drive_link

Table of Contents

Table of Contents

Formal Rules

What is Spec3?

Why not allow the 318i,323i/328i?

How do I get started?

Possible Order of Operations on a fresh build.

Preparing for your first track event

Finding the Right Donor Car

Spec3 Discounts/Benefits

OGRacing

Konig Wheels

RaceGerman

General NASA Member Discounts

Picking a number for your car

Parts Required

Eligible Drivetrain Table

Minimum Weight

Maximum Power

Motor

Engine Management

Transmission

Flywheel/Clutch

Intake

Exhaust

Suspension

Camber Plates

Front Control Arms

Front Struts

Rear Suspension

Rear Shocks

Springs

Anti Roll Bar (erroneously referred to as “sway bars” colloquially)

Wheels

Tires

Brakes

Fuel Tank

Drivetrain

Motor Mounts

Any non-solid motor mounts of the stock height. See Rule 9.3.1.8.1.

Transmission Mounts

Differential

Differential Bushings

Rear Subframe Bushings

Reinforcements

Chassis

Shock Towers

Bracing

Building Tips (in order of front of the car to the back)

Reaching minimum weight

Cooling system

Radiator ducting

Euro Coolant Tank

Heater Core Delete (not required)

Air Conditioner Pulley delete

Water temp sensor install

Brakes

Brake caliper rebuild

Brake cooling

Anti-Lock Brake System (ABS)

Three channel and four channel ABS

Brake pad part number explanation

Suspension

Wheel studs

96+ M3 control arms vs Non-M control arms

Front strut assembly

Fender Rolling

Front control arm bushing removal

Front control arm bushing install

Rear trailing arm bushing preload

Rear spring retainer install

Steering Wheel Lock delete

Electrical

Transponder

Killl switch wiring

Defrost/Defogging

EWS disable

Wire Harness Thinning - Chris Araj

Rain Light

Rain Light Wiring Tips

Engine

Oil pump nut

Oil Pan Baffle

Oil pump pickup tube

Oil Cooler

Engine Harness Diagram

DME Chip install

Valvetrain maintenance

Chassis

Roll cage Design

Cage Photos - Good

Cage Photos - BAD

Sound deadening removal

Mounting an E36 on a rotisserie

Polycarbonate Windows

Sunroof delete

Dual fuel pumps/fuel starvation fix

Mounting Ballast

Front subframe reinforcements

Rear Subframe reinforcement welding photos

Transmission

Transmission Shifter lever

Transmission shifter rebuild

Dual/Single Shear Selector Rod

Rear control arm reinforcements

Rear anti-roll bar endlinks

Wheels and Spacers

Exhaust install

E34 exhaust manifolds and downpipes

Safety Equipment

Seats

Seat back brace

Harnesses

Fire System

Roll Bar (for HPDE)

Vinyl/Decals

Car setup and maintenance

Regular Maintenance Intervals

Engine/Drivetrain

Chassis/Suspension

Safety

Alignment Specs (base line)

Suspension Setup - Shock settings and Anti Roll Bars

Brake pedal feel

Anti lock brakes

Body Panels

Cylinder Head rebuild

Head rebuild parts:

Engine Rebuild

Crankshaft bolt removal

Transmission removal/flywheel conversion/clutch replacement

Tires

Toyo RR

Toyo RA1

Buying tires

Tire Mounting and Rotation

Fluid Capacities and weights

Oil Filter Housing Welch Plug

CamShafts

In Car Camera

Rear Wheel Bearing Replacement

Reading codes from the DME/ABS

Towing

Ball Joint Pressing

Build Threads

Taylor’s 325

Sean’ 325

Tom Neely

Edward Higginbothom

To-Do List


Formal Rules

https://members.drivenasa.com/rules/spec3_rules.pdf

What is Spec3?

The NASA Spec3 (S3) racing class is devoted to BMW E36 325 models. The goal for Spec3 is to create high levels of competition between similarly prepared cars at a reasonable cost. Purchase and preparation of a car for these series should be less than $15,000. A Spec3 is great for HPDE and Time Trial duty while being built.

Spec3 is similar to Spec E30 but for the newer chassis. With limited engine and suspension modifications allowed, Spec3 ensures close racing, while not breaking the bank due to a plentiful supply of low cost street vehicles to convert. A spec Toyo tire and Koni/Swift suspension package take the guesswork out of building a competitive car and the series platform has proven to be as reliable on track as any existing class.

Where can a Spec3 race?

Why not allow the 318i,323i/328i drivetrain?

  1. The 325i and the M50b25tu engine from the 325i/525i is extremely plentiful and sells for $300 all day, every day. If you aren’t willing to sell your 328i to buy a 325i, reconsider how committed you are to racing.
  2. The m50b25tu torque curve is vastly superior to the m52 variants and makes good power all the way to fuel cut. It is a proper racing engine (m50 manifold on the m52 does change this, but we are talking stock for stock)
  3. The 325i is OBD1, meaning the DME(ecu) does not need to be programmed or flashed. Simply buy the Spec3 tune chip and install it on the board. This makes compliance testing simple
  4. Weight penalties to balance engines with different power levels and torque curves have proven to never be successful for tight racing. Spec3 is focused on car parity and the racing is tight enough that minute differences in torque across the rev range would cause disparity for consistent/fast drivers. (See other classes that allow the 328i). Spec Miata is one Spec class that allows different engines and the non VVT NB1 engine has proven to be a complete ringer and dominates the field. All 1.6 NA Spec Miata builds were instantly irrelevant when the NB was added.
  5. Spec E30 (325i) and Spec E46 (330i) do not allow other engines either. Need we say more?
  6. If you choose to use something other than a 325i (including an M3), most of the parts you’ll need to swap are listed here: https://docs.google.com/spreadsheets/d/1HLraPTno1H5gmn34nZpJ3OOsuwaK6uo6oFadOapUBuQ/edit#gid=0 

How do I get started?

  1. Come visit a NASA event! Find the registration table and ask for a map. Ask for the places to park and watch the racing action. Find the Spec3 paddock area and introduce yourself and ask questions!
  2. Read the rules! Read the NASA CCR, Spec3 rules, and your region’s supplemental CCR.
  3. Set your budget! Make a plan for how fast or slow you want to go. Ready to dive head first? Great! Make a plan and start sourcing parts! Want to stretch it out over a few years, no worries! Spec3 cars are great in HPDE and will be perfect for you while you build and work towards racing.
  4. Make some friends! The best part of racing are the friends you make along the way.
  5. 0Most importantly, have fun! Very few of us are racing for anything more than a trophy to put on a shelf. If you aren’t having fun, take a step back and reevaluate.

Possible Order of Operations on a fresh build.

This section will walk you through a potential order of operations when building a car and working your way through HPDE. Expected time to start in HPDE1 and make it to competition school is 2 years.

Year 1: HPDE 1 -> HPDE 2

Year 2: HPDE 2 -> HPDE 3

Year 3: Competition School in first event and rookie season of Spec3

This can be done faster or slower all depending on skill level, experience, and of course, luck.

  1. Join the Spec3 Facebook group!
  2. Read the rules and this manual!
  3. Find a donor car
  4. Do basic maintenance such as change all of the fluids, flush the brakes, and replace any worn suspension and brake components
  5. Install good brake pads (Something like a Hawk HT10) and do you first event! Get your feet wet and participate in an HPDE1 weekend.
  6. Search for safety gear. If you’re ready to take the plunge, it’s never too soon to get a full cage welded in and secure the relevant safety gear, but for now we will assume you aren’t ready for all of that. So source a quality roll bar, 2 race seats, brackets, harnesses, a helmet, and a HANs device
  7. After basic safety components are taken care of, you can continue driving HPDE1 weekends and we can assume you’ve moved up to HPDE2 at this point. The next logical step is to assemble your suspension and start removing interior pieces. Pull the carpet, AC components, radio, window regulators, and any other stuff you don’t need.
  8. Cooling system refresh! Pick up an aluminum radiator and a performance water pump with a metal impeller. Now is a good time to replace hoses and install a quality thermostat. Make sure all of your ducting around the radiator is intact!
  9. Install a fire extinguisher or fire suppression system!
  10. Start shopping for M3 control arms, m3 strut housings, the koni shock inserts, swift springs, sway bars, camber plates, chassis reinforcement pieces(rear subframe, trailing arm pockets, engine mount/subframe, sway bar), and buy some new poly/solid bushings (engine mounts, transmission mounts, stock front control arm bushings, stock rear trailing arm bushings with limiters, poly subframe and diff bushings, upgraded diff bolt, and new ball joints for the rear control arms)
  11. Pick up an oil pan baffle and drilled oil pump nut
  12. Install yourself, or take to a shop. Most of the chassis reinforcements need to be welded in. It makes sense to do all of your suspension work and bushing replacement at the same time since both the rear and front subframe must be dropped to complete the reinforcements. The front subframe must be dropped to do the oil pan and oil pump nut, so now is the time to do those as well
  13. Winter after first season. Congrats! You’re probably in HPDE2 or HPDE3 now. Time to get serious!
  14. Time to pick up a Spec3 exhaust and DME chip
  15. Now is the time to start contacting shops to see about getting a full cage welded in. You’ll probably need to book a few months out. See if they are willing to use your roll bar as a starting point for the main hoop and plan accordingly with what they say
  16. Additional weight loss. Now is the time to consider thinning your wire harness some more and gutting your doors in preparation for a full cage
  17. Get a fire suit if you haven’t already. This is your last season before racing, so get used to being in the fire suit with the shoes, socks, balaclava, and other fire safety gear. Ideally you already did this before you stepped on track!
  18. Now is the time to also go trailer shopping. You may have been driving to the track before, but with a full roll cage, this is no longer a good idea.
  19. Install the head light intake duct
  20. If you haven’t already, consider installing water temp, oil temp, and oil pressure gauges. The factory gauges are not very useful
  21. Strip your interior and get your cage welded in. Ask them to weld in your sunroof as well!
  22. Final prep. Rain light, install your stickers, rookie designation, kill switch, fire surpression system, window net, center net, a steering wheel with a quick release, etc.
  23. Complete competition school and go racing!

Preparing for your first track event

It’s very intimidating going to your first event, but it doesn’t need to be! Don’t be afraid to ask questions. Every single person there has been in your shoes before and can relate.

Prepare your car! There is only one word you need to think of right now and that's "safety". You're going to be putting yourself and an instructor (if you're at a good event) in your 30 year old car and hurling it 130mph down a straight.

Prepare yourself! Ask off of work for the event well in advance. Figure out your lodging (tent camping? Sleeping in your trailer or car? Getting a hotel? Hotels fill up fast so book early!). Find out where the restrooms are at the track. Do they have showers? Do they have food vendors or will you have to pack in everything. Does the track have a gas pump or must you bring fuel?

What to pack! Basic things like sunscreen, wallet, phone charger, your helmet are easy to remember, but there are some things you may not consider.

Now, here are some basic E36 parts to bring as spares

Okay, you’re all signed up, you’ve arrived at the track. Now where do you paddock? Drive around the paddock until you find someone in a similar car (in your case, an E36) and ask them if you can paddock near them. Even if they say no (very unlikely) they will probably have a good idea for where you can paddock and set up camp. Find the Spec3 racers near you and tell them you’re interested in the class and they’ll surely take you in. Having knowledgeable folks with the same car as you is invaluable.

You’re paddocked and ready to drive. What’s next?

  1. Take stock of your surroundings. Where is the medical area, where is registration, where is the tech station? Where is the entrance to grid, where are the restrooms, where can you get food, where can you get warm/cool/dry in case of inclement weather. Where is the closest spill clean up station, fuel station, or fire extinguisher?
  2. Prep your car. Clean out your car, no floor mats, no loose items, take out your spare tire, etc. Tape your numbers on, cover your battery terminals with tape, make sure your belts and everything are tight. Torque your lug nuts and check your tire pressure.
  3. Get your car tech’d. Go to the tech station (consult your schedule to see when they are open) and get your car approved by the tech inspector.
  4. Check in at registration. This varies region to region, so check your pre-event emails to see what they want you to do. Some don’t require check in and just call attendance at the driver’s meeting.
  5. Check the schedule and see where you need to be first thing in the morning. Usually there is an all hands driver meeting early, then your first class room session or run group meeting will be right after. Figure out where these will be and don’t be late!
  6. REST! Get a good night’s sleep. Wake up early and give yourself time to prepare and double check everything before going to the classroom. You may not have a lot of time after class to prepare for your first session.
  7. Have fun and ask lots of questions! HPDE is about learning, so soak it all in.

Finding the Right Donor Car

Sedans or Coupes are legal, but convertibles, compacts, and wagons are not. There is great debate on coupe vs sedan, but ultimately it’s down to personal preference and what clean chassis you can find. The coupe provides larger doors which aid egress, however the sedan’s rear doors aid in access to the rear seat area.  The most important thing to consider when sourcing a car is the quality of the shell.  Cars that have been in significant collisions should be avoided because the unibody may be out of alignment.  Cars with significant rust should be avoided because rust may compromise structural components, rust repairs can be expensive, and the rust may reappear in the future.  High mileage drivetrains are often still competitive and high miles should not discourage a potential buyer. The best cars to look for are 93-95 5 speed manual 325i or 325is models with the winter package for the 3.15 limited slip differential. Some later 95 models with the winter package may have traction control (the second throttle body being a telltale sign) and these will NOT have a limited slip differential.

Areas to inspect when looking at a potential shell/car:

Spec3 Discounts/Benefits

The following deals and benefits have been arranged by the stewards of Spec3 or NASA itself to facilitate affordable builds

OGRacing

Spec3 previously had “special pricing” at OGRacing, but as of 2024, NASA has arranged for all members to get special pricing. Try the NASA general process first (https://nasaspeed.news/columns/nasa-news/nasa-launches-all-new-racing-gear-store-operated-by-og-racing/) and if that ever goes away, the Spec3 process involves emailing or calling OGRacing and asking for Spec3 pricing. They will confirm with Spec3 series leaders if you are on the list of confirmed Spec3 builds in progress or complete, and then calculate the special pricing.

Konig Wheels

Spec3 racers can purchase Spec3 legal wheels from Konig for ~30% off retail. Visit this link for details

https://konigwheels.com/nasa-spec-3/

RaceGerman

Spec3 racers get a discount across the entire https://racegerman.com/ parts catalog. Contact your series leader for the discount code. Spec3 builders also get a STEEP discount on the Spec3 legal headlight duct from RaceGerman separate from the general discount. Contact Taylor Johnson to have a promo code generated to use for this special discount.

Tulay’s Wire Werks

Mention Spec3 when ordering wire harness thinning services from Tulay’s Wire Werks and receive a discount. Kevin will check with us to confirm you are legit, so reach out to your series leader if you don’t think we are aware of you and your build! Tulay’s Wire Werks is the most popular (by far) service for thinning factory harnesses for Spec3 and Spec E46s https://tulayswirewerks.com/

General NASA Member Discounts

All NASA Members have access to the following benefits as well https://members.drivenasa.com/benefits

HRB Performance

Rebate on initial purchase of DSSR with proof of running decal

https://www.hrberformance.com/store/p/hrb-early-model-e36-dssr

AKG Motorsport

Contact Taylor Johnson

Andrew Racing

Discounted Hawk DTC-60 brake pads stamped with Spec3

https://andrew-racing.com/c-892868-nasa-spec-pads-nasa-spec-3.html


Parts Required

Parts list: https://docs.google.com/spreadsheets/d/1OlOMni51nbqwuyZUN7aE8V9y77sN1THtBnFW9rwHqmM/edit#gid=0

Eligible Drivetrain Table 

Year

Car/Chassis

Type

1993-1995

325i / E36

Sedan

1993-1995

325is / E36

Coupe

The Spec3 class is designed around the 1993 – 1995 BMW 325i sedans and 325is coupes.  See Rule 6.3.1 and Appendix A.   In addition, any 1992 – 1999 BMW E36 chassis may be used provided that all relevant components (motor, engine wiring harness, transmission, brakes, etc.) are used from a 1993 – 1995 production vehicle. See Rule 9.3.2.2.

Minimum Weight 

2825lbs including driver, fluids, etc.  See Rule 9.2.1 and Appendix A.

Maximum Power

195.9 horsepower and 179.9 foot pounds of torque as measured by a dynamometer at the rear wheels.  See Rule 9.3.1.9.1 and Appendix C.

Motor

2.5 Liter single-vanos inline six cylinder motor known as the BMW M50b25TU. See Rule 6.3.1. and Appendix A.

Engine Management

Stock Bosch DME, part numbers 0-261-200-413 or 0-261-203-506, with Bimmerworld performance chip, part number #Chip_BWS3.  See Rules Section 9.3.1.7.

Stock DMEs are commonly known as Red Label (no EWS) and Silver Label (with EWS)

https://www.bimmerworld.com/Chips-Software/Chips-/Spec3-Performance-Chip-by-Epic-Motorsports_2.html?

Transmission

Stock Getrag 250 five-speed transmission. This transmission came in the E34 525i, E36 318, 328, and 325, as well as the E46 325i and possibly others. All Getrag 250 models in the USA will have a casting number on the side starting with “220”. This does not mean they are a Getrag 220, which was offered on the E36 318i in Europe. All getrag 250s are the same in the US except very late model units on the E46 325i which may have an input shaft with more splines. S5D 250G-TAJT is the code for the early coarse spline in our cars and S5D 250G-TBDS is the code for the late model E46 transmissions with the fine splines .Pictured below is the correct E36 spline count and the 2004 E46 325i spline count.

Automatic to manual swaps are fairly straight forward. Here is a great guide http://shatteredk.blogspot.com/p/e36-1993-325is-bmw.html

Flywheel/Clutch

Stock flywheel and clutch or an approved single mass flywheel kit of the same weight as stock.

The Valeo Single Mass Flywheel conversion kit is the most popular

BMW Flywheel Conversion Kit - Valeo 52281208

https://www.fcpeuro.com/products/bmw-clutch-kit-323i-323is-325-325e-325es-325i-325is-525i-52281208

Intake

Stock air intake with K&N or Green Filter air filter and optional “S3 Air Duct” sold by Bimmerparts.com and available via the Ebay store of seller “cmuzyy.”  See Rules Section 9.3.1

https://www.ebay.com/itm/BMW-E36-Headlight-Air-Duct-Insert-For-Spec3/284060071541

If the Ebay link ceases working, you can order directly from Bimmerparts:

Chris Muzylowski

Zygmunt Motors

www.bimmerparts.com

215 348 3121

215 688 1350

cmuzyy@aol.com

New for 2023, the Race German Headlight Duct is also legal. This duct has much better fitment, but costs a little more. Spec3 racers get a great discount on this part, so do not pay retail! Ask a Spec3 racer how to get the discount for the entire RaceGerman Catalog https://racegerman.com/products/e36-headlight-duct?_pos=2&_sid=f167ceb55&_ss=r

Exhaust

Stock exhaust manifold and collector pipes followed by the Spec3 exhaust sold by Mitchum Enterprises Richmond, VA (804) 402 1239; richard.mitchum@gmail.com.  See Rule 9.3.4.1.

Installation of this exhaust requires you cut the exhaust on your car right after where the two pipes join in a “Y” after the header, before the catalytic converter. This exhaust will then clamp on using exhaust clamps. You may weld any of these portions together.

You can also build your own exhaust, but it must meet the specifications of the Spec3 exhaust listed in the rules. See the exhaust install section later in this document.

Suspension

The Spec3 suspension setup is Swift springs and koni yellow strut inserts on an M3 (1996-1999) strut housing modified to take a strut insert. These are paired with Vorshlag camber plates and 96-99 front lower control arms.

There is a spec eibach anit roll bar kit that must be used as well. This kit is NLA as of 2021. The replacement for this part are similar sized H&R bars. See the anti roll bar section later in this document.

The rear suspension is just a koni yellow shock and a swift spring.

Basically they make aftermarket shock inserts that allow you to cut your stock m3 struts and pull the factory shock tube out. Then you slide the aftermarket one in and attach it with a bolt through the bottom.

Camber Plates

Vorshlag Motorsport part number VM-CP-SPEC3 and spring perches part number VM-SP-96S-14. See Rule 9.3.8.1.

https://vorshlag-store.com/products/vorshlag-camber-plate-and-perch-kit-for-spec3

Front Control Arms

BMW part numbers 31-12-2-228-461, 31-12-2-228-462, and 31-12-9-069- 035 from the 1996-99 BMW M3.  See Rule 3.8.2.

These are sometimes hard to find. Note that the 96-99 M3 arms are DIFFERENT than the 95 M and 92-99 NON M arms. The M3 arms use a centered bushing while the other arms must use an offset bushing to have the same geometry and they are NOT ALLOWED. Pick up a used set of 96-99 M3 arms and press in new ball joints. If you want more information on how to identify the correct arms when buying new, search for the control arm section later in this document.

Part numbers for the ball joints needed !!!YOU MUST RUN THE LEMFORDER E30 M3 BALL JOINTS. ALL OTHER BALL JOINTS ARE NOT HEAT TREATED AND YOU WILL RISK SNAPPING THEM!!! - PER RRT

Outer BMW Ball Joint - Lemforder 31121126254

x2

ttps://www.fcpeuro.com/products/bmw-ball-joint-front-outer-31121126254l

Inner BMW Ball Joint - Lemforder 31121126253

x2

https://www.fcpeuro.com/products/bmw-front-inner-ball-joint-e30-lemforder-31121126253l

Front Struts

BMW part numbers 31-31-2-228-007 and 31-31-2-228-008 from the 1996 – 99 BMW M3 modified with Koni front strut inserts, part number 8641-1342S3.  See Rules 9.3.8.4.1 and 9.3.8.4.3.

For detailed steps on how to assemble the front struts, look in the Building Tips section later in this document.

Rear Suspension

Stock M3 upper and lower ball joints, part number 33-32-1-140-345, and stock   rear trailing arm bushings, part number 33-32-6-770-817.  RTAB shims (limiters) are highly recommended. See Rule 9.3.8.15. One thing to note is that the NON M cars have a bushing for the rear lower outer control arm connection to the trailing arm. It is legal and recommended to upgrade this to the M3 ball joint, which is used on the rear upper outer trailing arm connection. 33326775551

33-32-1-140-345 has been superseded by 33-30-6-852-895 and is also legal

It is highly recommended you weld in the rtab pocket reinforcement plates. Here is an example of RTAB Pocket failure https://www.youtube.com/watch?v=J4zPECASIrs...

Subframe bushings can be poly, delrin, or any other non-metallic material but you must also weld in the reinforcement plates if you do that.The inner bushings on the upper and lower control arms are usually fine to leave alone but not a bad idea to replace if everything is dropped. It is recommended to replace your diff bushings while you are in there and upgrade to the LARGER front diff bolt.

Part

Part Number

Quantity

Useful Link

33-32-1-140-345

33-32-6-770-817

Rear Shocks

Koni part number 8240-1115S3. See Rule 9.3.8.3.1.  Stock rear shock mounts, part number 33-52-6-754-096. See Rule 9.3.8.12.

Part

Part Number

Quantity

Useful Link

8240-1115S3

33-52-6-754-096

Springs

Swift Race Springs, front and rear, part “NASA Spec3.”  See Rule 9.3.8.7.1.

These springs are designed specifically for Spec3 and have a front spring rate of 375# and rear rate of 550#. The rate is progressive and the springs lower the car substantially.Contact RRT Racing in Sterling VA as they carry these.

https://www.rrtautomotive.com/rrt-racing/spec3/

703-661-4222

DO NOT FORGET TO INSTALL THE PLASTIC SPRING RETAINERS OR YOUR SPRINGS MAY FALL OUT

Anti Roll Bar (erroneously referred to as “sway bars” colloquially)

Eibach front and rear, part number 2033.32.  See Rule 9.3.8.8.

https://stillen.com/products/eib2033320?fbclid=IwAR3pD3ybOpgumbQBLoShwFm-VkVrzKZSLnuwGKr1EHXO9tYul-NU6-vVaKs

As the Eibach kits are harder to find, new for 2021, you can run this H&R kit in its place

https://www.bimmerworld.com/H-R-Sway-Bar-E36-M3-Rear.html?fbclid=IwAR0QLho6JcgeQsjyLmSFKrrSsHDngnzACO4Ag72-S_QPRuKu2U-mYIcKn_s

https://www.bimmerworld.com/H-R-Sway-Bar-E36-M3-Front.html?fbclid=IwAR1OcT4rMs0nqyKDy_ZgG3el6Xx2wYRBX9rL1mqdr_kmjwEelbZMKJxMDik

Wheels

Wheels shall be either 15 inches by 7 inches, with a minimum weight of fifteen and one half half (15.5) pounds OR 17 inches by not more than 8.5 inches with a minimum weight of sixteen and one half (16.5) pounds, and can be any brand, unless otherwise specified in these regulations. All wheels on the vehicle must be of the equivalent size

Tires

Toyo Proxes RR in size 235/40/17 (dry conditions),  or 225/50/15 Toyo RA-1 (wet conditions).  See Rule 9.3.9.1.

Brakes

Stock non-M calipers and rotors with Hawk DTC-60 front pads, part number NBS3F or HB136G.690, and Hawk DTC-60 rear pads, part number NBS3R or HB227G.630.  See Rule 9.3.10.1.

FCP Euro carries our brake pads and they honor the lifetime warranty, so you can buy one set and then warranty them for a new set again and again forever.

These can be found at Andrew-Racing as well

https://andrew-racing.com/i-23456440-nasa-spec-3-front-nbs3f.html

https://andrew-racing.com/i-23456442-nasa-spec-3-front-rear-combo-nbs3f-nbs3r.html

The stock caliper brackets can be upgraded using the same part from a Z3. https://www.facebook.com/groups/spec3/posts/3654181118016336/

Fuel Tank

The stock, unmodified fuel tank must be retained. No fuel cells are allowed. The stock fuel tank is well protected, low to the ground, and well separated from the passenger compartment.

Drivetrain

Motor Mounts

Any non-solid motor mounts of the stock height. See Rule 9.3.1.8.1.

Transmission Mounts

Any non-solid transmission mounts of the stock height.  See Rule 9.3.12.5

Differential

3:15 ratio limited slip differential.  See Rules 9.3.11.1, 9.3.11.2, and Appendix A.

These differentials were standard on OBD1 cold weather package cars.

Differential Bushings

May be upgraded with aftermarket bushings, including metallic. See Rule 9.3.11.4.

It is a common mod to drill the front diff bushing and install a larger bolt. E36s are known for snapping the stock size bolt under hard acceleration.

Rear Subframe Bushings

May be upgraded with non-metallic aftermarket bushings. See Rule 9.3.8.9.1.

Reinforcements

Reinforcement of the following components is highly recommended but not required:

Chassis

Rear sway bar pick-up points, front subframe motor mounts, rear lower control arms, rear trailing arm pockets, and rear subframe attachment points, BMW part numbers 41-00-2-256-495, 41-00-2-256-496, 41-11-2-256-497, and 41-11-2-256-498. See Rule 9.3.8.11

Shock Towers

Front shock tower, part number 31-31-2-489-795, and rear shock tower, part number 51-71-8-413-359.  See Rule 9.3.8.13

Bracing

Front X-brace, part number 51-71-8-410-212, and any bolt-in front and rear shock tower braces.  See Rules 9.3.8.14 and 9.3.8.10


Building Tips (in order of front of the car to the back)

Reaching minimum weight

The following most likely need to be done to a prepped car to reach race weight

  1. Wire harness thinning
  2. Polycarbonate rear side windows (windscreen and rear glass must remain stock)
  3. Wire harness thinning
  4. Heater core removal
  5. Door gutting
  6. Lightweight battery
  7. AC/Cruise Control delete
  8. Interior stripping/Sound deadening removal

Cooling system

The achilles heel of most BMW engines is the cooling system. Early M5/X engines came with a plastic composite water pump impeller that would come apart and let the engine over heat. These engines do not tolerate high water temps (260+) and will quickly warp or crack the head.

It is suggested to upgrade to a performance water pump with a metal impeller such as a Stewart unit, along with a metal thermostat housing (replacing the stock plastic part) and an aluminum radiator such as a CSF or Mishimoto. Some racers elect to run a lower temperature thermostat as well.

Radiator ducting

It is IMPERATIVE that you have at least the factory radiator ducting (top, sides, and undertray) to ensure adequate air flow through the radiator. The next step to upgrade beyond that is an undertray with an integrated radiator baffle (such as the Motion Motorsport unit) or a dedicated radiator duct such as the Kinematic Speed Radiator Duct kit.

Euro Coolant Tank

The late model E30 tank / E36 Euro tank is self bleeding and allows you to delete your fan shroud. It is a major upgrade over the stock unit.

E30 late-model 6 cyl. tank (17111712641)

Front Plastic Clip: (17111719190)

Rear Euro Mount (41122256492)

Installation

  1. Relocate the battery terminal by notching the metal:
  2. Drill a couple holes and mount the battery terminal:
  3. Make a bracket out of aluminum stock for the front plastic clip:
  4. Rivet the rear euro mount/bracket to the firewall:
  5. Wedge the rear of the tank into the euro mount and snap the front clip into place:

Heater Core Delete (not required)

To get down to the class weight, most Spec3 drivers delete their heater core. This has the added benefit of removing hot coolant from the passenger compartment, simplifying the cooling system greatly, and clearing up space under the dash. See the image below for a basic visual of what hoses to delete and which ones to connect.

Air Conditioner Pulley delete

If you delete the AC pulley on the crank, you will need to either add washers to the crank pulley bolts or to use shorter bolts. The E36 M3 LTW came factory with no AC, so there is a part number for these bolts. You need 6. https://www.fcpeuro.com/products/bmw-hex-bolt-with-washer-m8x12z31-07119913011

A block off plate must be installed on the rear of the head http://www.hardmotorsport.com/hard-motorsport-heater-core-coolant-block-off-plate-bmw-e36-m3/

Then, a heater core firewall block off panel MUST be added

http://www.hardmotorsport.com/hard-motorsport-firewall-hvac-block-off-plate-bmw-e36/

Water temp sensor install

In the diagram above, there are three ports on the intake side of the head. The farthest to the rear of the engine is a coolant passage that gets blocked off when doing a heater core delete. This nipple can be removed and replaced with a water temp probe. Most likely, you will need an adapter such as this: Extended 12x1.5 to 1/8" NPT Adapter https://www.bimmerworld.com/Gauges-Data-Acquisition/Data_Gauge_Sensors/Extended-12x1-5-to-1-8-NPT-Adapter.html?gclid=CjwKCAjwx8iIBhBwEiwA2quaq71wS-gWFhSysWSp0VhRg-hrU2ZEkc1Z6SVpuZsVKUX-lT6-Ssf4AhoC3MEQAvD_BwE to thread into the head, which will then accept the water temp probe.

Alternative: Part number A2C59517248S threads right into the extra port on the head without any adapter

https://www.summitracing.com/parts/vdo-a2c59517248s 


Brakes

Brake caliper rebuild

The piston for the front brake calipers may be listed incorrectly. This is the correct part https://www.rockauto.com/en/moreinfo.php?pk=13228349&cc=1433882&pt=1724&jsn=10

Brake cooling

This topic is up for debate, but the general consensus is that running at least the factory brake ducting is recommended if you are a front runner in the class. The Hawk DTC-60s operate fine and do not fade or drop off unless you are pushing the car 10/10s in a hot summer event. Expect to replace your rotors every 3-5 events as they will crack. Some racers elect to run dedicated brake ducting systems and results are unclear. Brake pad temperatures will be kept lower and basically eliminates brake fade, but at the potential cost of cracking rotors more often. Some racers elect to block off the brake ducting for better aero and better rotor life. If this is done, you should at least remove the dust shields behind the hubs. Your mileage may vary.

Anti-Lock Brake System (ABS)

Before reading any further, understand that an E36 with no ABS, all else held constant, is slower than one with ABS. If you hold the false bravado stance that you are better than ABS, you do not drive fast enough on track. If your Spec3 build does not have the stock ABS in a functional state, you will be faced with an exercise in frustration. Do not modify your ABS, do not mess with the wires. Leave it alone. With no ABS on an E36, the brake bias is not correct. With no ABS on an E36, you can not push the car to the edge as required to compete in a spec class without ABS.

Wheel speed sensor connectors can get wet during very heavy rain and cause an intermittent failure that will turn your ABS off. Clean off the connectors, apply dielectric grease, and seal them up. Otherwise, the ABS system is maintenance free and fairly simple.

Three channel and four channel ABS

Late model cars may have 4 channel ABS (the difference being separate ABS control over the rear wheels instead of one single ABS valve for both). In theory this may provide an advantage, but no advantage has been observed in practice. 4 Channel ABS cars usually came with ASC+T when equipped with the winter package whereas 3 channel cars would come with a limited slip with the winter package. There is no different in maintenance, handling, or build prep for these two systems.

Brake pedal travel sensors

Some early model cars have a sensor on the brake booster to inform the ABS system how far the pedal is depressed. This is a good place to start looking if your ABS isn’t working. However, there are multiple versions of this sensor with different lengths. It may be possible to determine what length/style sensor you need by matching the color on the cap of the sensor to the paint mark on your brake booster. (Credit: Andy Schmidt)

Brake pad part number explanation

Hawk brake pad part numbers consist of:

The part number “HB136

The pad material “G” for DTC-60
The pad thickness including backing plate “
.690

Brake pedal feel

The E36 is known for sub par pedal feel at times. The easiest fix for this is to bleed your brakes at least every other event and try to keep fresh brake pads on the car. If your pedal feels vague and squishy, it’s likely your pads are worn. Replacing the brake pads will bring back a surprising amount of pedal feel.

A lot of racers also install solid brass caliper bushings to normalize pad wear and reduce the taper of the pad material. These must be cleaned and lubricated every event.

Anti lock brakes

99% of issues with ABS on these cars is due to the wheel speed sensor. If you have an ABS light come on and the ABS itself not functioning, disconnect the sensors, dry them out, and reconnect with some protection from moisture. If this does not work, check the gap between the reluctance ring and the sensor. If it’s off slightly, the ABS may function intermittently and not throw a code properly.

If this does not solve your issue, inspect the wires from each sensor back to the ABS module on the passenger side under the dash and confirm there are no breaks in the wires.

A proper BMW scanner such as the Schwaben Foxwell unit can read ABS code, show live data, and even active ABS components. These are very useful.

A “hardware monitoring” code on your ABS likely means the module itself is broken.

There are 2-3 common ABS modules for these cars.

ABS Module Part Numbers

Cars without ASC+T
Prior to 08/1994
 - boxier module that uses a connector like the DME with a silver label (34521162646)
After 08/1994 - smaller module and uses a small connector like on the back of the gauge cluster with a green label (34521163089).

Cars with ASC+T

Before 09/1993 boxier module that uses a connector like the DME with a yellow label (34521090029)

After 09/1993 - boxier module that uses a connector like the DME with a yellow label (34521164023)

After 09/01/1993 (possibly auto transmission?) boxier module that uses a connector like the DME with a brown label (34511162662)

After 02/20/1995 boxier module that uses a connector like the DME with a yellow label 34521163002

Rotor coating and wheel stud failure

There are an increasing number of suspicions that thick coatings on rotors that can be displaced by heat and wheel torque can lead to failure of wheel studs. Uncoated rotors, or removal of the coating on the bell of the rotor where it meets the hub, spacer, or wheel is suggested. https://www.core4motorsports.com/coatings-and-wheel-stud-failure


Suspension

Wheel studs

It is highly recommended that you convert the wheel lug bolts to wheel studs. Only use a high quality kit such as the race studs from Bimmerworld and replace them every 1-2 seasons.

96+ M3 control arms vs Non-M control arms

The 95 M3 used the same control arm geometry as a regular E36 but with an offset bushing to give extra caster.

From September 95 onwards BMW did away with the offset bushing and fitted all M3s with concentric/non-offset bushings, with the additional caster coming from a new control arm design.

A lot of online vendors will list the NON M part as fitting the M3 and pair it with an offset bushing. This is NOT the arm you should use for Spec3. The easiest way to tell the arms apart is that the M3 arm has the outer ball joint centered in line with the control arm where the non-m (and 95 M3) arm has the ball joint offset and this creates a little “dog leg” bend.

Pictured below (the non M arm on top (black), the M3 arm on the bottom (silver)). Note that the color and number of holes in the arm are not indicators.

Source: Vorshlag

Front strut assembly

The front strut is a combination of a 96-99 M3 strut housing, plus a koni sport shock insert, Spec3 Swift Spring, and Spec3 camber plate from Vorshlag

  1. Use a spring compressor to compress the spring on the strut (if installed) and remove the top nut on the upper spring plate (top hat/strut mount)
  2. Remove the spring and spring compressor
  3. Drill a small hole in the bottom of the strut housing to drain the oil oil
  4. Cut the top of the strut housing off
  5. Remove the “insides” of the strut
  6. Enlarge the hole in the bottom of the strut housing
  7. Install the koni insert and secure the fastener on the bottom. *NOTE: Sachs struts may have a smaller inner diameter than the genuine BMW strut housings, so the Koni inserts may need to be sanded down to remove excess paint in order to fit* *NOTE: The bolt thread pitch changed sometime between 2021 and 2022 with old inserts using an m12x1.5 and new ones have been found to use an m12x1.75. Do not reuse old bolts and check the thread pitch!*
  8. Optional: Unthread the top of the shock insert a few turns and apply blue loctite to ensure the shock does not unthread itself from the vibrations and twisting forces of racing
  9. Place the spring and Spec3 camber plate onto the strut and fasten the top nut

Fender Rolling

To fit the wide 235/40/17 tires and 17x8.5” wheels, you must roll (the process of flattening the inner lip of the fender) and aggressively pull (physically stretching outward) the fenders, or else your tires will rub on your fenders causing smoke and burnt rubber smell at best and a damaged/punctured tire at worst.

Front control arm bushing removal

Use of a 2 or 3 jaw puller, or the special control arm bushing tool will aid in the removal of the bushing from the control arm. Then you can use a ball joint tool or a press to push the bushing out. You may also elect to cut the outer case of the bushing, then use a punch to bend the metal case back to more easily remove the bushing.

Front control arm bushing install

Spec3 runs the 96+ M3 version of the front control arm bushing. These are usually NOT found already pressed into the lollipop. Use of a press or a front ball joint tool kit will aid in pressing these bushings into the lollipop. Image below.

The M3 bushing differs from the non M bushing by having more rubber and, naturally, less holes. An M3 bushing will only have two small holes and they are supposed to be to the left and right of where the control arm installs into the bushing once everything is assembled on the car. However, for added stiffness, you can rotate the bushing 90 degrees before installing it into the lollipop.

Install of the bushing in the lollipop onto the control arm can be done by hand by spraying windex or soapy water (NOT something that will leave a slippery residue) on the control arm and pushing the bushing on with both hands, however, there are tools you can buy or make that allow for easier install, especially wit the control arm already on the car.

Rear trailing arm bushing preload

Rear spring retainer install

The Spec3 swift springs are short enough to fall out when the suspension is at full droop.You must drill a pilot hole in the “nub” that centers the stock spring and install the supplied spring retainers with the supplied bolt to “extend” the nub to retain the stock springs. Drilling this hole is easiest when the upper control arm is in installed, however, if you use a small right angle drill or an electric/air ratchet, you can still get to the nub. (Source: Ross Shull)

Steering Wheel Lock delete

From the factory, the E36 has a lock that will prevent the steering wheel from turning when the key is not inserted into the ignition and turned to “run”. Per the Spec3 rules, this MUST be removed. Removal is as simple as drilling a small hole in the bottom of the ignition, reaching into the hole with small needle nose pliers, and pulling out the spring.

Rear shock mount install/washer order

Is it very important that the correct washers are installed on the rear shock mounts. Missing either the top or bottom washer will lead to the shock piston pushing through the mount. Photo from PelicanParts

Electrical

Transponder

A transponder is a box that transmits a unique number to the timing system as you drive over the start/finish line. Most organizations use what NASA uses, which is an AMB/MyLaps system. Your transponder should be placed as low and as far forward on the car as possible. Any obstruction between the transponder and the ground can negatively affect the signal to the timing loop. A transponder being farther forward on the car can mean the difference between 1st and 2nd place on a photo finish. Transponders can usually be rented from a NASA region per event, but it’s best to buy your own. Older transponders (the red ones) branded “AMB” work forever without a subscription and are highly sought after on the used marked. Newer silver ones branded “MyLaps” require a subscription fee to be purchased every year to continue to work. As of 2023, there are supposed new AMB transponders without subscriptions required. The registration booth in some NASA regions will have a tester to tell you if your transponder is working or not. Do not purchase the orange dirt bike/karting transponders. They will not work at speed on a race track. You should check “RaceHero” online during practice/warm up each day to confirm your transponder is “hitting”. Check your regions policy on registering/updating your transponder number, each region is different.

A popular place is on the frame rail.

Killl switch wiring

Per the CCR, every race car must have a kill switch. This switch must not only disconnect power from the battery when turned off, but it must also disable the car and turn the engine off. The only exception here are items like electric fire suppression, radios, cool suits, etc. This switch should be placed in a place easily reached while you are strapped in your seat, and also by emergency workers from outside the vehicle. Purchase a quality switch as you don’t want this part failing in the middle of a race, or 5 minutes before the flag drops! See below for a common way to hook up a 6 pole switch on an E36. A 2 or 4 pole switch will not work. Install video: https://youtu.be/muV5hNmvaas?si=MT3YNURD7U0MZ5Xf

Photo credit: Eric Donovan

Defrost/Defogging

It is suggested that you install something like the bimmerworld defrost kit, or install a blower motor to blow air from the transmission tunnel to the windshield to use as a defroster. At any rate, you should invest in some RAIN-X Defogger spray or dish soap to coat the windshield with.

EWS disable

On OBD1 cars, if the chassis was equipped with EWS (silver label DME), you need to remove that link between the EWS computer and the DME as well as use an EWS delete chip (Spec3 chip). The wiring can be disconnected at the DME side (pin 66) or at the X20 side (pin 7). The X20 is the easiest to access and cleanly modify.

We recommend pushing the pin out of the X20. (big round plug by the fuse box.) If you unscrew that connector, pull back the boot, find pin 7 (green wire), twist the lock mechanism on the connector, push the pin (pin 7, green wire) out of the connector, re-lock the connector, fold the pin/wire back into the boot, put the boot back on, and reconnect the connector.

For EWSII equipped cars, there is also a starter lockout. We recommend bypassing that as well. On the EWSII module itself, there are only two large wires. Those are the wires for the starter solenoid. Cut them near the plug and butt connector them together and your car will start even when the key transmitter or antenna fails. (https://www.trmtuning.com/2013/10/11/ews-e36-chassis/)

Wire Harness Thinning - Chris Araj

Tools

Method

The general concept is to remove unnecessary wires without leaving any wire stubs or exposed wire ends.  To do this, you will need to depin the terminals where the wires end.

The two logical ways to work are:

  1. From known unnecessary end points to the fuse box
  2. From known unnecessary fuses to end points

In either case, it is easiest to work with one wire at a time.  Depin or clip (situational) the wire that you no longer need.  Feed the wire through the wire bundles until you reach its end point.  If necessary, use a blade to cut a small break in the electrical tape and unwrap a wire bundle.  Depin or clip (situational) the end.  Add your removed wire to the discard pile and watch it grow!  (weighing your removed parts is very satisfying)

If you get into a situation with several partially removed wires, keep them organized with color coded zip ties or tape.  Bright colors are easiest to see through the mass of wires.

Depinning Common Terminals

Wire terminals have small flanges which catch the terminal housing and prevent them from coming out.  The function of the terminal release tools is to compress these flanges and allow the user to pull the wire out of the housing. (see example CNTCT socket here)

Tips

General Wire/Housing Colors

Below are trends I noticed, not necessarily a fully accurate guide

Wires:

Wire Terminal Housings:

Sample Thinned Fuse Box

(pictures of mine coming soon when I finish reassembly and make sure it works)

Rain Light

Some regions require a rain light to be installed (notably, NASA Mid Atlantic). Be sure to install an FIA approved light such as the Lifeline or Afterburner unit. You will be disqualified if the race is announced to be a rain race and you do not have a rain light

https://www.pegasusautoracing.com/productdetails.asp?RecId=560

https://www.bimmerworld.com/Safety-Race-Interior/Battery-Electrical/Lifeline-FIA-Approved-LED-Rain-Light.html

NASA Mid Atlantic (the only NASA region to require a rain light), AER, and BMW CCA require the rain light to flash at 4hz at all times, except when braking, at which point the rain light should go “Solid”.

Rain Light Wiring Tips

Pegasus Afterburner: Simply connect power and ground, then connect the third wire to a signal that goes 12v high when the brake pedal is applied (such as your brake light wire)

LifelIne: Purchase the relay adapter https://www.bimmerworld.com/Safety-Race-Interior/Battery-Electrical/Lifeline-Rain-Light-Adapter-On-Flashing-Brake-Solid.html?fbclid=IwAR0WCDxnEKTozp8iMOI3qfiod9cYA5DvCgNaBbEP8MzvuKL3_gdEwkQLkyk

Or wire yourself like this (Source: Jon Kozlow)

Cartek:

Wiring should be straightforward with the Cartek. Hook the solid light wire into the tail lights and the strobing/flashing light wire into your brake lights.

Temperature Sensors and low Power

There are two water temperature sensors on the m50, on the side of the head, under the intake. One sends information to the gauge cluster and one sends information to the DME. The connectors are the same but the sensors are different. If you have these connectors swapped, the DME will read low temp and you’ll be down on power and the gauge cluster may read hot. One temp sensor is blue, one is black, and usually the connector with the blue inside connects to the BLACK sensor, and the connector with black inside connects to the BLUE sensors (opposite from what you expect). The best way to confirm is to get the engine up to temp and use an OBD1 scanner to read the temperature from the DME. If it reads low (usually 20-30 degrees too low), then either the sensor is bad or the connectors are flipped.

The gauge cluster temp gauge is HIGHLY buffered. The needle will reach the vertical 12 o’clock position when the engine reaches 170 degrees and will not move again until the engine reaches 240 degrees. Your temp needle being a few degrees left or right of vertical means nothing as when the temp truly does cross the 170-240 threshold, the needle will move very noticeably in that direction.

Engine

Oil pump nut

The oil pump nut on these engines can get loose when the engine is turned backwards due to a spin on track. This problem is made worse by the lack of a tensioner on the oil pump chain. The slack creates an impacting motion on the sprocket which can work the nut loose. The fix for this is to safety wire the oil pump nut to the sprocket.

https://www.bimmerworld.com/Engine/Engine-Performance/M50-Drilled-Oil-Pump-Nut_2.html

Oil Pan Baffle

It is suggested to run a baffled oil pan and also overfill by 1-2 quarts to avoid oil starvation during sustained later Gs. Installation of an oil pan baffle is as simple cutting off the one rivet that holds the stock baffle in, clearing the pan, and then welding in the new one with a few stitch welds.

Oil pump pickup tube

It is HIGHLY recommended you replace your 25+ year old oil pickup tube with the upgraded z3 part which is reinforced to avoid cracking. A cracked oil pickup tube will destroy your engine.

https://www.fcpeuro.com/products/bmw-suction-pipe-11411703930

Don’t forget the gasket! https://www.fcpeuro.com/products/bmw-oil-pump-gasket-11411703947

Oil Cooler

E36s did not come with oil coolers and they are not necessary. Most Spec3 racers do not run them, however, if you do choose to run one, the most widely accepted best option is a kit using a euro s50/Z3m S54 oil filter housing as they are already set up to run an oil cooler.

Engine Harness Diagram

The following is not 100% accurate, but should assist in figuring out what goes where if you did not label them during disassembly

Source: https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/265351-m50-52-s50-52-harness-diagram-simplified

DME Chip install

  1. Locate the DME cover on the passenger side firewall
  2. Unscrew the screws holding the cover in place
  3. Slide the DME out and unplug the connector
  4. Use a screwdriver to pry back the metal tabs
    on the bottom of the DME
  5. Lift the cover off of the DME
  6. Locate the chip on the board and
    pry up gently with even pressure all around
  7. Install the new chip with decoder board in place
    of the old chip. Press gently and evenly to secure it
  8. On later cars, you will need to cut the green
    wire on the main DME loom on the driver side
    of the car to disable EWS

Valvetrain maintenance

It is highly recommended by the author of this guide that the 30+ year old 200,000 mile valve spring retainer plates be replaced before forcing the engine to live at 6500 RPM for 40 minutes at a time. This is easily done without removing the head from the engine as long as the proper tools are used. The valve can be kept in place using pressurized air in the combustion chamber or something like pushing string into the spark plug hole and rotating the engine to top dead cylinder. Then a spring removal tool can be used to press down on the spring, remove the valve stem keepers, then the spring can be released and the upper spring retainer plate replaced. New stock plates are more than enough for the rigors of racing (for the E36. E46 is a different story), If this maintenance is not done, you risk a plate cracking and a valve falling into a combustion chamber, destroying your engine. This can happen without warning with 30 year old plates.

Spark Plugs

The NGK BKR6E is pretty widely recommended as the best spark plug for the m50b25tu.


Chassis

Roll cage Design

!!!!Please read section 15.6 of the NASA CCR thoroughly!!!! 

The follow list contains suggestions for roll cage design. YOU are responsible for the cage installed in your car passing a NASA tech as well as being Spec3 legal, which are separate things. When in doubt ASK YOUR SERIES LEADER. It is highly suggested a trained professional cage fabricator be consulted or contracted to install a cage in your race car. This is a one time expense and is the most important part of your car. If using someone else to install the cage, make sure they understand the CURRENT requirements of NASA for cages and also understand the limitations to your cage design required running in a spec class. These cages cannot contain many of the things done to NASA GTS cars, for example. A video guide can be found here: How to build a NASA Spec3 (e36) legal roll cage

The following kit has been used with success by DIY Spec3 builders, but it does require additional cuts, bends, and fabrication to install https://rollcagecomponents.com/bmw-e36-basic-econo-roll-cage-kit/

Requirements

  1. This class only allows a 6 point cage, meaning the cage can contact the body at the base of the A, B, and C pillars only. Foot protection bars are allowed in addition to these 6 points of contact. Additional attachment points from the roll cage to the chassis are not allowed.  For example, gussets to the pillars, tabs welded between the roll cage bars and the chassis, and custom seat frames that tie into the roll cage and the floor, are not permitted."
  2. 15.6.4 Padding All roll cage surfaces that may come in contact with the driver’s head, knees, and elbows must be padded with high-density padding such as Ethafoam or Ensolite or other material labeled “high density padding” and manufactured for road racing use.
  3. Full 360 welds on all tubes
  4. Optimal tube sizing for our cars is as follows
  1. 2501 - 3000 lbs 1.500” x 0.120” Seamless Alloy (4130), Seamless mild steel (CDS Mechanical), DOM, or Docol R8 (only) 1.750” x 0.095” Seamless Alloy (4130), Seamless mild steel (CDS Mechanical), DOM, or Docol R8 (only) 1.750” x 0.120” ERW* (No issuance of logbooks for cars with ERW cages) *Note- Specifications listed only for reference for inspection of grandfathered vehicles
  1. Ideally, the rear down tubes specifically land on the rear bulkhead or the trunk floor (photos below). The rear down tubes touching or being welded to the shock towers becomes a complex gray area of the rules. Avoid welding anything to your rear shock towers to avoid any doubt in your cage legality
  2. Cage mounting points should be a flat plate or a rectangular plinth welded directly to the floor. No triangular plinths or floating plates welded to the sides of the chassis.Welding the plate or plinth to both the floor and an adjacent vertical surface is permitted

“Nice to have” Cage Design Tips

Cage Photos - Okay

More photos of good cages here: https://drive.google.com/drive/folders/1WNCISWBqpLtHfppqAysM5y8qLSmxefNG

 

Cage Photos - BAD

Sound deadening removal

There are two ways to remove the sticker tar-like sound deadening material. Heat or dry ice. Most cars respond well to the dry ice method where you freeze the sound deadening and then hit it with a hammer to break it away from the chassis, but these cars do not respond will to that and the clean up can get nasty. Most find success with a heat gun, a scraper, and mineral spirits or some other adhesive remover.

Before:                                                         After:

Mounting an E36 on a rotisserie

 

Polycarbonate Windows

Often referred to by the most popular brand name as “Lexan”. Polycarbonate can be used to replace the side window glass to prevent shattering and to reduce weight. Polycarbonate CANNOT be used for the front and rear windshields. Popular options are Condorspeedshop and Hard Motorsports for prefabricated solutions of you can purchase the raw material and cut your own. The weight savings between the full glass and polycarbonate is not much. In our tests we found that stock rear glass from a coupe weighs about 6 lbs, the condor speed shop coupe window weighs 3 lbs, and the Hard Motorsports window weighs about 2 lbs. At most, you are saving 4 total lbs by swapping your free stock glass, for polycarbonate you paid money for.


Sunroof delete

The sunroof cassette should be removed and the stock panel or another piece of steel should be fixed in place in the roof. No aluminum, titanium, carbon fiber, fiberglass, etc.

After removing the cassette, remove the sunroof panel from the cassette and attach it to the roof with tabs, either welded in or screwed in with the factory holes. Seal around the sunroof panel with sealant of your choice. Wrapping the roof in vinyl provides a clean look and superior sealing.

Dual fuel pumps/fuel starvation fix

With the 25+ year old fuel pump in your car, you may experience fuel starve in long right hand turns when below ⅓ tank. There are a few legal options to remedy this.

  1. Some people have found that simply replacing their pump with a new one allows them to run down below ¼ tank without issue. Your mileage may vary
  2. Most people install a second fuel pump in the driver side of the tank, replacing the sending unit. There are multiple ways to do this
  1. You can run the 95+ model year blue top pumps and just plumb the feed lines together going to the fuel rail, this is not suggested
  2. The better option is to run two white top pumps and plumb the return from the rail into the return on the the driver side pump, then send the feed from the driver side pump to the passenger side return, then have the passenger side feed the fuel rail like normal. The Bimmerworld kit does exactly this. https://www.bimmerworld.com/Intake-Fuel/Fuel-Filters/E36-Fuel-Starvation-Kit.html?gclid=CjwKCAjwx8iIBhBwEiwA2quaqzD52jLP1VvCK1vPxBKv9AhBbFOb7P-3Mjk4Xu9K2q6tnSTmr1qM4BoC98MQAvD_BwE

Mounting Ballast

15.20Ballast All ballast shall be solid metal such as steel, lead, or depleted uranium, and consist of a minimum of five (5) pounds per piece. Each piece shall be bolted in place with through-bolts, fender washers, and a locking-nut / system (e.g. jam-nuts, Nylock, etc.). All ballast shall be secured sufficiently, and all bolts shall be of grade five (5). Nylock nuts or metal crimping lock nuts should not be reused.

9.3.13.2 Ballast is permitted, and shall be securely mounted in the passenger foot well, aft of the firewall, and shall be forward of the rear seat riser.

9.3.13.2.1 Ballast shall be in segments no heavier than fifty (50) pounds.

9.3.13.2.2 Ballast may not exceed one hundred (100) pounds maximum. Spare Tire weight per 9.3.9.7 is considered separate from this rule and may be added in addition to the allowed 100 pounds.

9.3.13.2.3 Each segment shall be fastened with a minimum of two (2) one-half (1/2) inch bolts and positive lock nuts of SAE grade 5 or better unless the ballast is mounted using the four (4) passenger seat mounting points and replacement bolts, and shall utilize large diameter, load distributing washers.

9.3.13.2.4 Holes may be drilled in the passenger footwell floor pan for purposes of mounting the ballast and the floor pan may be reinforced for the same purpose.

Front subframe reinforcements

The front subframe should be reinforced where the engine mounts are located. The stresses of more solid bushings and the NVH of a race car can lead to failure of the mounting location. Popular reinforcement kits will include a plate that welds inside the mount pocket where the bottom nut for the mount will rest as well as a plate to gusset the bottom of the “cup”. Some may elect to also reinforce the area around the inner ball joint to spread the load from the nut more widely.

Rear Subframe reinforcement welding photos

Transmission

Transmission Shifter lever

The stock shifter is more than adequate for racing as long as the bushings and bearings are not worn. If your car has a sloppy shifter, consider rebuilding it properly for $50 before spending $500+ on a chassis mount or short shift kit.Some race shops claim anecdotally that chassis mount shifters cause extra wear on transmissions due to the increased shift speed and pressure on synchros. These claims have not been proven, however.

(Image source: https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/141583-shifter-assem-getrag-250)

Transmission shifter rebuild

Unlike the ZF from the 328i and M3, the Getrag 250 never needs any kind of rebuild to assist in alignment of the shifter, so there are only two areas of concern.

If you’d like an easy button, one click refresh kit and an upgrade to your stock shift lever, the Z3 shifter is widely considered the best OE shifter available. A kit like this contains everything to bring your shifter back to life as well as and upgraded shift lever for a shorter throw. https://www.fcpeuro.com/products/bmw-short-shift-kit-e30-e36-e30ssk

Shift Lever 

This is the part you physically grab to shift gears. The length of the shaft above and below the pivot “ball” where it sits in the cup of the shift linkage determines the “throw”. The Z3 shift left offers one of the shortest “Throws” of any BMW shifter and is easy to find.

Shift Linkage

This part of the shifter attaches to the rear of the transmission with a pin through a bushing in the front of the linkage and then slides into a bushing attached to the chassis on the underside of the transmission tunnel. This part of the shifter, when worn, will allow the shift lever to move vertically, rotate in place, and be vague during shifting. The shifter lever sits in a “cup” in this linkage and this is the pivot point. This is the part removed and deleted when installing a chassis mount shift since the pivot point then moves above the transmission tunnel. To rebuild this part, source the following parts:

Bushing for the front of the linkage https://www.fcpeuro.com/products/bmw-shift-lever-bushing-oem-25117519669

Bearing Cup for the linkage https://www.fcpeuro.com/products/bmw-shifter-bearing-top-ring-25111220600

Rear bushing for the chassis

https://www.fcpeuro.com/products/bmw-shifter-bushing-rear-25111222015

Selector Rod

The lower part of the shifter is the “Selector rod” that connects the bottom of the shift lever to the actual shifter rod of the transmission. There is a bushing in the bottom of the shift lever where the selector rod connects, a circlip to hold the selector rod in, and then a “selector rod joint” which has a foam bushing inside and connects the selector rod with the shifter rod in the transmission. Older style selector rod joints needed little plastic shim washers whereas the updated style you can buy currently do not need those washers anymore. The selector rod is the main reason for side to side movement of the shifter as the joint bushing wears and simply due to the “single shear” design of the selector rod.

Selector rod joint https://www.fcpeuro.com/products/bmw-selector-rod-joint-25111222688

Selector rod shims (if you don’t change the rod joint to the updated version. You can also add more of these washers than stock to increase the rigidity of this joint) https://www.bimmerworld.com/Driveline-Shifter/Shifters-Parts/Yellow-Plastic-Shim-25-11-1-220-439.html

Some people have found that wrapping the selector rod in safety wire or something similar and then wrapping it in tape, you can add weight to the shifter to improve the feel further

Shift knob

The stock 325i shifter can easily be upgraded with a ZHP weighted shift knob for better shift feel.

Dual/Single Shear Selector Rod

Something like a dual shear selector rod can be installed during your rebuild (to replace the stock single shear selector rod) to eliminate side to side movement of your stock shifter. The selector rod is different depending on what year car you have.

BMW beefed up the "gear shift rod joint" starting in 9/1994 and also made it 10mm shorter. To accommodate this, the selector rod was lengthened 10mm. In the photo, the pre-9/94 linkage is on the bottom with the post-9/94 linkage on top.

Up to 09/1994

Selector Rod - 25111221547

Gear Shift Rod Joint - 25117503525

From 09/1994

Selector Rod - 25111222664

Gear Shift Rod Joint - 25117580281

When installing a DSSR, you are likely going to need to shave/sand/trim off the sides of the bottom of the shift lever and the sides of the selector rod joint. The DSSR will be a very tight fit on these two parts.

Rear control arm reinforcements

It is recommended that the rear control arms have a reinforcement plate welded on.

https://www.bimmerworld.com/Suspension-Steering/Control-Arms/E36-E46-Rear-Lower-Control-Arm-Reinforcement-Kit.html

Rear anti-roll bar endlinks

Most racers use the stock endlinks for the anti-roll bars. If you choose to use adjustable endlinks, such as bimmerworld or AKG endlinks, you will likely have to shorten the threaded rod of the endlink by cutting it to avoid having the endlink contact your lower control arms in the rear.

Wheels and Spacers

Wheel spacer guide: https://www.facebook.com/groups/spec3/permalink/2712605542173903

To fit 17x8.5 ET40 wheels, you must run a spacer on the front of the car to clear the spring perches. Any spacer smaller than a 12mm should not be used as they lack sufficient “lip” material on the center bore. A 15mm spacer in front and a 12mm spacer in the rear is normal as usually you can not achieve enough camber in the rear to clear the fender with a 15mm spacer. Cars running a 17x8 et38 such as the Konig Hypergram can run without spacers at all, however, this is not the most performant setup and you will rub the inner fender well at full lock. If you are lucky enough to find 17x8.5 ET20 wheels, you do not need spacers at all, but may have issues with rubbing in the rear.

Rain wheels

The best wheels to buy for the 15 inch rain tires are the stock wheels from an E34. They will be 15x7 ET20 which gives the correct offset with no spacers. These wheels are basically worthless, so you won’t see them for sale. Just make a “WTB” post somewhere and people will throw them at you. Expect to pay ~$25 a wheel.

Exhaust install

  1. Cut your stock exhaust behind where the two pipes from the manifold join, but in front of the catalytic converter
  2. Leave extra pipe uncut as you can always cut more off, but adding it back on is more difficult
  3. Use an exhaust pipe expander if needed to slide the Spec3 exhaust over the cut end of the stock exhaust
  4. Weld the pipes together or use the supplied clamps to secure the exhaust
  5. Transfer the exhaust hangers to the Spec3 exhaust and secure it to the chassis

E34 exhaust manifolds and downpipes

Although the E34 525i did come with the M50b25tu in later years, the exhaust manifold and downpipes are slightly different as the flanges are clocked in a different orientation. Beware when purchasing an E36 engine that you will have to swap the exhaust manifold

Safety Equipment

SAFETY IS A SYSTEM. When you are in HPDE, the safest your car will be is STOCK until you install every and ALL safety items designed to work together. Do not install fixed back seats without harnesses and rollover protection. Do not install harnesses without a roll bar or cage. Do not install a roll bar or cage and drive it on the street if there is any chance any part of your body can make contact with the bars. Do not wear harnesses without a head and neck restraint. Do not remove your airbag unless you are always going to wear a harness with a helmet with a HANs. See how this works? It’s a system. Complete it, or it’s unsafe. Once you install harnesses, it’s probably time to start towing the vehicle to the track. Yes, the people you follow on instagram all have racing wheels, fixed back seats, and harnesses in their street cars. They are posers. You are the genuine article. Recognize and understand that those setups are less safe than stock unless they are wearing a helmet and a HANs at all times.

Seats

Seats are important. They hold you in place and also connect the most important sensor in the vehicle (your butt) to the car. NASA requires an in data FIA rated seat and (if made of a composite material) a seat can be used up to 5 years after expiration with the use of a seat back brace. Be sure to purchase a quality seat from a reputable source (such as OGRacing, Competition Motorsport, HMS, TMI, etc).

It is always recommended to run a containment “halo” seat to protect your head from side impacts. It is required if you do not run a center net, but a center net is always recommended as well.

To mount a racing seat in your car, you will need:

  1. BMW specific floor mount adapters (an example can be found in the Spec3 Parts list)
  2. Side mount (or less commonly, bottom mount) brackets (example also in the Spec3 parts list)
  3. A seat
  4. A roll bar or roll cage with a harness bar to attach the shoulder harnesses to
  5. Harnesses
  6. A way to secure the antisubmarine and lap belts to the chassis (easiest way is to drill holes in the floor of the car and use thread backing plate)

Shown above, an image of floor adapters mounted to the floor alongside eyebolts for the antisubmarine belts.

Shown here: the backing plates underneath the car that the eyebolts thread into.

Seat back brace

Harnesses

6 point belts should be used

Harnesses with the thinner 2 inch shoulder straps are preferred with use of a HANs

Fire System

NASA requires a full fire system. A fire system consists of a charged bottle of some fire suppressant, tubing, nozzles, and pull cables. Most fire bottles are only good within 10 years of manufacture and must be serviced every 2 years. That means a bottle made in 2013 is no longer good in 2024 and cannot be serviced. A bottle made in 2022 is good, but needs to be serviced in 2024 if it has not already been. Usually, manufacturers recommend that the fire bottle be mounted transverse, meaning the top and bottom of the bottle face the sides of the vehicle. Bottles should never be mounted vertically. There should be at least two pull cables for the fire bottle, with at least one reachable by a driver strapped in the car and at least one able to be pulled from outside the car.

Steering Wheel/Quick release

A popular budget quick release set up is the NRG 2.5 quick release https://www.amazon.com/gp/product/B005U85RYG

Paired with a name brand OMP or Momo hub adapter

https://www.bimmerworld.com/Safety-Race-Interior/Steering-Wheels/OMP-Steering-Wheel-Hub-Adaptor-E36.html 

Window Net

Window nets should cover at least 50% of the window opening. The easiest style window net to install is the style with the straps that tie to the door bars at the bottom. The top of the net should have a rigid bar that either is spring loaded, or has a latch/clip at the end to lock into place. The window net should not be able to pop out by being pulled on or pushed.

Vinyl/Decals

Required stickers for the car:

RRT Spec3 Stickers - Obtained from RRT or series leader

NASA sticker on all 4 corner - Available in registration or online

Koni sticker on sides - ???

Numbers on sides per CCR regulation

Class designation

Last name on windshield and side windows

Contingency:

If you want to claim contingency prizes for any eligible vendor, you must consult their decal placement guidelines and also submit the proper paper work. Popular contingency programs in Spec3 include Toyo and Hawk. https://drivenasa.com/contingency-programs/ Contingency decals can be found at the tech shed in your NASA region

Spec3 Logo and dimension (Files found here: https://drive.google.com/drive/folders/1duTOMlrXnQavBIuO1j21PQbNSKkSSFXb)

We suggest all Spec3 racers run the largest “Spec3” logo they can on their car. It leads to great photos and promotes the class.

The rear quarter panel of an E36 can accommodate up to about a 29”x9” Spec3 logo.

 

If you have a primary sponsor that requests the quarter panel location or you just don’t want to run a Spec3 logo there, you can fit a Spec3 logo underneath the door molding line as long as it’s under 7 inches tall.


Car setup and maintenance

Regular Maintenance Intervals

You should “nut and bolt” your car before every race weekend, and check some items between every race. Some things should be inspected more thoroughly in the off season by removing them or testing them, and sometimes even proactively replacing them when nothing is visibly wrong with them.These are rough suggestions for how often to check items and does not indicate an item does not need replacement or inspection more or less often than stated.

Engine/Drivetrain

Chassis/Suspension

Safety

Alignment Specs (base line)

https://www.bimmerforums.com/forum/showthread.php?995556-The-Definitive-Alignment-Guide-for-your-E36-M3

Front

Camber: -3.5 to -4.0 deg per side

Toe: 0

How to achieve that much camber in the front.

  1. Cut a section out of the lip of the strut tower reinforcement plate if you have one installed to allow the camber plate to be adjusted to max camber. DO NOT CUT THE SHOCK TOWER ITSELF. THIS IS ILLEGAL
  2. Add washers or shims to the bottom of the strut where it meets the hub/knuckle

Rear

Camber: -1.8 to -2.2 deg per side

Toe: 0 to 0.10 total toe in (IIRC this is 1/8" total toe in)

Suspension Setup - Shock settings and Anti Roll Bars

A good baseline is to set the front anti-roll bars to full soft (unless your car has the old red eibach bars, then front should be full stiff) and the rear to full soft. Also set the front shocks to full stiff (then turn it back a turn) and the rear to full soft (and turn it back a turn). Stiffen the rear bar to induce more rotation in the car. A full stiff rear bar leads to a very loose car and may be too loose for some tracks where corner exit speed is most important.

Body Panels

Coupes and Convertibles share body panels except for the trunk. Sedans do not share body parts with the coupe or convertible except for the front and rear bumpers. Body panels from 92-99 models will all fit, however, the nose panel and bumper are different on 92-95 and 96-99 models. The E36 compact (318ti) is a sedan from the a pillar forward, so hood and fenders will swap to a sedan.

Cylinder Head rebuild

It is the general consensus that a healthy, strong, front running motor can be had with a simple head rebuild and leaving the bottom end alone. You can mill the head .03mm before needing a thicker head gasket. If you mill beyond .03mm, there is a thicker head gasket made by victor reinz that will make up the milled material and restore your compression ratio to factory spec. The more you mill without making up the space, the higher your compression ratio will be and your cam timing may eventually be slightly off. Hot tanking the head, lapping and grinding the valves, and refreshing the Vanos will net a strong motor, assuming the bottom end is fine. E36 engines have been known before to have valve retainers crack and cause a valve to drop due to age or high revs. It is wise to replace all the retainers and springs, but most do not. If you have a noisy engine when hot, it may be worthwhile to replace the lifters as well when you rebuild the head. Note: It is rumored that BMW upgraded the spring retainers after 1995 to a hardened steel part, so any engine with the original spring retainers will have the weaker pieces and any retainers purchased new will be the stronger versions.

Head rebuild parts:

24 x BMW 11341724991 (Valve spring plate “retainer”)

https://www.fcpeuro.com/products/bmw-upper-spring-plate-11341724991

48 x BMW 11341461405 (Valve keeper)

https://www.fcpeuro.com/products/bmw-valve-keeper-collet-11341461405

ELRING Head Gasket Keep (includes valve seals) BMW 11129064467

https://www.fcpeuro.com/products/bmw-cylinder-head-gasket-set-elring-11129064467a

Engine Rebuild

The M50b25tu rarely, if ever, requires more than just a head refresh (covered in the section above). However, if you choose to rebuild your engine’s “Bottom end” keep in mind that oversized pistons allowed in the rules, in conjunction with a freshly rebuilt head, will likely place you over the horsepower cap. Oversized pistons can be sourced from CS-Parts.de is not found stateside. If possible, just go up a size on the piston rings after a light cylinder hone, and inspect/replace rod bearings.

Crankshaft bolt removal

The highest torque bolt on the E36 chassis is the crankshaft bolt. Even with the engine in the car, in 5th gear, with the handbrake pulled, this bolt can put up quite a fight. Crafting a holding tool either from cut metal or by welding a pipe to a spare harmonic balancer will assist in removal. The pipe can either wedge against the floor or a frame rail. The CAD files for the custom cut tool can be found in the files section of the NASA Spec3 Discussion group on Facebook. (Images courtesy of John Buffington and Scott Gress)

Transmission removal/flywheel conversion/clutch replacement

  1. DISCONNECT THE BATTERY AS YOU WILL BE WORKING NEAR THE STARTER
  2. Remove exhaust.
  3. Remove heat shields.
  4. Rip out the insulation on the transmission tunnel. This stuff is likely falling apart already and makes seeing what you’re doing much harder
  5. Unbolt the CSB.
  6. Unbolt the guibo and move driveshaft out of the way
  7. Optional: unbolt driveshaft from diff to completely remove it.
  8. Unbolt slave cylinder with the two 13mm nuts
  9. Unclip reverse switch
  10. Disconnect shift lever on top by removing the circlip from the selector rod at the bottom of the shift lever
  11.  Remove the "bitch clip” that holds the “shift linkage” to the top of the transmission. Use a flat stubby screwdriver with the handle towards the front of the car and slide it under the clip to pop it up. Rotate the clip vertical and slide it to the side to pull the pin out of the end of the shift linkage
  12. Pull the shift lever and linkage forward to pull the rear of the linkage out of the chassis mounted bushgng
  13. Drop the shifter out
  14. Loosen engine mounts a bit so the transmission can tilt.
  15. Remove transmission cross member and support trans with jack.
  16. Tilt the transmission back and use 2-3 feet of extensions to get to the bell housing bolts and starter bolts (Early model cars may have a nut on the other side of the starter bolts)
  17. Level engine and transmission and slide the transmission straight back.
  18. Inspect and replace guibo and CSB at this time. Pay attention to guibo orientation. The arrows point towards the flange. Preload CSB properly.
  19. REPLACE CLUTCH FORK PIVOT PIN with the stainless steel one from an e31, NOT BRASS. https://www.fcpeuro.com/products/bmw-ball-pin-21511223281
  20. Replace throw out bearing
  21. Replace pilot bearing. This can be removed by stuffing wet paper towers into the hole of the bearing until the space behind is full, then tap a socket through the center of the bearing. The paper towels will push the bearing out. Some people use bread or soap as well.
  22.  inspect transmission input seal and output seal.
  23.  Inspect rear main seal.
  24.  Use the valeo single mass flywheel conversion kit if not reinstalling the factory dual mass flywheel. Do not replace the dual mass flywheel with a new one as they all fail. If replacing the flywheel, use a legal single mass kit.
  25. Fly wheel hardware should be replaced

Tires

Toyo RR

Toyo RA1

Buying tires

As of April 2023, the best price for our tires can be found by emailing Phils Tire Service and asking to join their “Toyo Club” which is free. Then order your tires from them and mention the toyo club when you do. They also take Toyo Bucks.

https://philstireservice.com/

TrackDayTire offers a similar program. Ask a fellow racer for more information

Tire Mounting and Rotation

https://www.toyotires.com/media/1720/tsd-12-023-rr-dot-mounting-orientation-recommendation.pdf

Fluid Capacities and weights

Item

Weight

Capacity

Engine Oil

 5w-30, 10w-30, 5w-40, 10w-40, 5w-50, 10w-50

6.5-7.5 qts

Gear Box

 D4 ATF (most common factory fill, but not most common refill) Most use Redline MTL (70W80) or Redline MTL-90 (75W90) or equivlalent

1.5 qts

Differential

75w-140 GL5

1.8 qts

Coolant

Distilled water + water wetter

11 qts

Oil Filter Housing Welch Plug

The oil filter housing went through various revisions. Some units have press fit plugs while others have threaded plugs. If your housing has the older style, non threaded plugs, they use an o ring to seal and this can start to leak. This is the part number that can be used to replace it.

https://www.facebook.com/groups/spec3/posts/4372544982846609/

Left: Older style with the welch plug and circlip. Right: Newer style with threaded plug

Source: https://www.bimmerforums.com/forum/showthread.php?2466605-M50-S50-Oil-Filter-Housing-Leaks-%28not-gasket%29

https://www.bimmerforums.com/forum/showthread.php?2086017-S52-Oil-Leak-Filter-housing-has-screw-in-plugs-which-are-leaking-can-t-find-info

CamShafts

In Car Camera

NASA requires a front facing camera for all competitors. Some regions will even issue a fine for racers without footage. Some things to consider when looking for a camera.

  1. Reliability
  2. Ease of use
  3. Quality/Angle
  4. Mounting Options
  5. Price

Whatever camera you use, it must be reliable. It must work every time, not die in the middle of the race, and the footage needs to be easily accessed. GoPros are the most common, however, they are difficult to hardwire to the car, so you must stay on top of battery life. Something like an AIM SmartCam is very reliable, but expensive and has worse quality.

Ease of use. GoPros are at the bottom of the spectrum for ease of use for racing. Keeping the camera charged is a constant worry and remembering to turn the camera on is a hassle. There’s nothing worse than lining up for the flag and remembering your camera isn’t on. Something like a dash cam or SmartCam will turn on automatically with the car or with a switch.

Quality/Angle: GoPros and other high end cameras have the best quality, often recording in 4K 60FPS or higher. AIM Smarty cams and similar are middle tier, and dash cams are often the worst quality. GoPros can be mounted in a lot of different ways and the price point and the fact they are battery operated means you can run multiple GoPros in interesting locations. DashCams usually have a fixed field of view and need to be mounted on the front or rear glass, so you won’t capture much cockpit content unless you spring for a dashcam that also captures footage inside the cabin.

Mounting options: The general rule of thumb is that capturing the action in front of the car is most important. A clear view through the windshield to show the action on track is crucial. The footage captured is used in compliance rulings when an incident occurs, and not having the footage to prove it’s not your fault is a massive bummer. If the camera can also capture your steering, gas, and brake inputs, that’s even better as it can also help capture your intent and your actions behind the wheel. This is also good for coaching/data. Many people find that mounting a GoPro to the main roll cage hoop places the camera too far to the rear of the car to get good footage, so a mount that can move the camera forward in the cabin is good.

Price: Dashcams are uber cheap. GoPros and the additional hardware are a bit more expensive, and then options like a SmartCam or Garmin Catalyst top the market in the quadruple digits.

Data: The Garmin Catalyst and AIM Smartycam can fully integrate with your data, the AIM can also integrate with your car’s sensor data to allow some neat stuff. GoPros can capture speed, direction, GPS, G forces, etc and overlay. Dash cams may provide GPS/Speed.

Rear facing footage: It is a really good idea to at least get a cheap dash cam to capture rear facing footage in the event that something happens behind you.

Example of good and bad angles. Both images are a GoPro Hero 7 Black The top image is using a fancy mount that moves the GoPro up and forward. The bottom is a normal GoPro roll bar mount. Notice how the top angle captures the driver’s inputs but also maximizes the amount out the windshield that can be seen.

Rear Wheel Bearing Replacement

Symptoms of a bad wheel bearing are grinding or popping noises and/or excessive play in the wheel hub when shaking it back and forth. Wheel bearings should be replaced every 2 seasons or so for a full time race car. At best, a failed wheel bearing will slow you down and make the car handling unpredictable, and at worst, it can cause the wheel to come off or cause damage to expensive parts like the trailing arm assembly or axles. Replace the rear wheel bearings is a serious job that requires the correct tools. If you are considering replacing the rear wheel bearings on your Spec3 without proper rear wheel bearing tools, you are in for a tough time.

Parts required:

New Wheel bearings

New hubs (if the hubs are original to the car or you aren’t certain you can remove the old ones without damaging them)

New axle nut

New bearing circlip

Tools required:

BMW Rear Wheel Bearing tool or FWD Bearing Tool

Hub Puller/Slide Hammer

  1. Start just breaking the 30mm axle nut loose on the axle
  2. Jack the car up and secure it
  3. Spray the axle shaft splines with penetrating oil. This are usually stock in place
  4. Remove the brake rotor and caliper
  5. Remove the external torx bolts that hold the axle to the differential.
  6. Unbolt the exhaust and/or sway bar to allow the axle to drop down away from the diff
  7. Thread the axle nut out, but do not remove it completely
  8. Attach a puller (I use a 3 jaw puller) to push the axle shaft out of the hub to the rear
  9. Remove the axle nut and finish pulling the axle shaft out
  10. Attach the hub puller/slide hammer to the hub and slide hammer it out of the bearing. The hub should come out with the inner race of the bearing still attached
  11. Optional: If you are reusing your old hubs, cut a slot in the inner race stuck on the hub with a dremel and use a cold chisel to break the race off the hub
  12. Remove the wheel bearing circlip on the outside of the bearing
  13. Insert your bearing tool with the “cup” on the outside of the hub and the smaller diameter puller on the inside of the hub. Pull the bearing out to the outside of the trailing arm bore
  14. Be careful not to damage your wheel speed sensors when doing so
  15. Use a wire wheel to clean up the trailing and snap ring groove
  16. Optional: Place your wheel bearings and hubs in the freeze to shrink them
  17. Place the wheel bearing into the trailing arm and flip your bearing tool around to pull the bearing into the trailing arm bore from the outside. Continue until it bottoms out. You may apply anti seize compound to the bore
  18. Install the bearing circlip
  19. Place the hub into the bearing and draw it in with the bearing tool. You may apply anti seize to the inner bore of the bearing. Be sure to support the inner race on the backside when drawing the hub in
  20. Reinstall axle shafts into the hub
  21. Bolt the axle onto the diff flange
  22. Install the axle nut and torque, then punch in the locking tabs Reinstall brakes, wheels, tires
  23. Check torque after your first session with your fresh wheel bearings

Reading codes from the DME/ABS

Despite being OBD1, the E36 325i does offer up a lot of information from its various modules if read with the correct scanner. A tool like the following can read live data and pull codes from the DME as well as the ABS module including temps, misfires, wheel speeds, etc. It can also activate certain things like the ABS pump, ABS valves, and even individual fuel injectors. https://www.turnermotorsport.com/p-555295-professional-bmw-scan-tool-with-20-pin-adapter-cable/?gclid=CjwKCAjwl6OiBhA2EiwAuUwWZejJ3dUOYLX_qjwo_yDvaQ9HMtQcjLweaDTTnxjUx1zJ_o1-BWZsARoC8FMQAvD_BwE

If you have the appropriate computer and connection cable, applications such as INPA and ISTA can be used to read directly from the 20 pin diagnostic port under the hood. This is what BMW dealerships of the time would have done.

Towing

You need at least a 15 foot deck to tow an E36 safely, most elect for an 18 foot deck to keep the rear of the car off the “dove tail”.

You can tie the car down with wheel straps, or more commonly, use the factory tie down holes above the plastic “jacking pads”. “T hooks” are designed to fit in these holes and then your straps can attach to them. https://www.bimmerworld.com/Trailering-Tie-Down-Hook-Set-of-4.html

However, using the factory holes requires a “Cross strap” tie down method which has its own set of pros and cons.

https://racer.com/2020/02/26/towing-101-tie-down-gear/

Ball Joint Pressing

1-1/2” pipe fittings can be used for pressing new ball joints into control arms.


Frequently Asked Questions

Q: Picking a number for your car


A:
Each region treats car numbers differently in regard to uniqueness. Some regions require a number be unique across all racers and even TT and some don’t even require a unique number within the same group. Be sure to read your region’s rules. Here are some links to region info:

Mid Atlantic: https://members.drivenasa.com/events/4187

Northeast: http://nasane.com/northeast-reserved-number-list/

Southeast: https://docs.google.com/.../1ny0Vk9HmMi.../edit...

Great Lakes: http://nasagreatlakes.com/CarNumbers.aspx

Mid-America: https://drivenasamidamerica.com/getti.../number-reservation/

Arizona https://nasaaz.com/car-numbers/

Rocky Mountain https://www.nasarockymountain.com/reserved-car-numbers

Q: Why is “X” not legal in Spec3?


A: Rules for “Spec” racing classes operate differently than other “open” classes. The rules do not specify what you
cannot do, but instead, specify what you can do. The goal is that your car is stock in every way except where the rules specify you can do something to change the car in a way that it was not from the factory. Rules to allow new things you can do to your car are only added when there is a demonstrable “need” for that rule. For a new rule to be added that allows a part to be installed on a car, thorough testing must be done to confirm that part cannot be used or abused to have a competitive advantage, the rule must be clear enough that compliance officials can easily determine if a part is in compliance with the rules at the track, and a justification needs to be present as to why it is a detriment to the class to not allow that new thing.

Q: How can I suggest a new rule for Spec3?

A: Some classes have a specific time of year where rule change requests are “open”. Spec3 does not operate that way, and instead takes requests/suggestions for new rules year round. Rule suggestions can be filtered up through your series leader unofficially, or can be officially requested by emailing the national series leader with your request. Series leader information can be found here: https://drivenasa.com/staff-directory/

Q: Who determines if a new rule is to be implemented?

A: Spec3 currently has a rules panel consisting of veteran racers from various regions. Rule change requests are reviewed, research is conducted, and rules that the panel decides are worth adding are sent to NASA National for approval and publication.

Q: How often are the Spec3 rules updated?


A
: A new ruleset is published yearly in the winter, and occasionally mid-season in preparation for the NASA Championships. Mid season updates are usually limited to clarifications, not major changes.

Q: How do points work? What championships can I compete in?

A: NASA is divided into “Regions”. Each region has a schedule that spans across various tracks in its geographic area. Racers racing in a region will receive season points based on finishing positions and the racer with the most points in a region at the end of a season is the region champion. NASA also has a National Championship in September. Racers from any region can compete as long as they have completed the required amount of regional races (usually 2-3 race weekends). https://drivenasa.com/championships/

Q: How do I race with Spec3?

A: https://www.youtube.com/watch?v=8-qf_B36mnM

Q: Why isn’t the class called Spec E36?

A: While the true history and context is probably lost, the fact remains that BMW Club filed for the trademark “Spec E36” a couple years after Spec E30 took off with NASA. Spec3 is unable to call itself “Spec E36” even as the leading spec class for the E36 made by the same people that created Spec E30. For more information, read this https://community.drivenasa.com/topic/75615-what-is-the-difference-between-spec3-and-spec-e36/


Uploading Spec3 Media to the shared drive for Social Media

Sharing videos and photos from the Spec3 event you are at to the social media team is essential to the continued growth of Spec3. Please try to take interesting videos and photos of the racers and cars whenever you can and upload them to the shared drive following the steps below.


1a. Upload them here

https://drive.google.com/drive/folders/1IONmw-Z_9_iMqweU8Ht5QEJs4xmhQ5NE



1b. Or upload them here if you can’t figure out Google Drive
https://www.dropbox.com/request/mZZx0fsvD2SR3olvRqW0

2. message the Spec3 account to let them know you have.

If you’re on a mobile phone, open your browser settings and check the box to “Request desktop” site and you’ll see the upload button at the top left.

Build Threads

Taylor’s 325

https://community.drivenasa.com/topic/58630-the-cart-before-the-horse-my-spec3-build/ 

Sean’ 325

https://www.bimmerforums.com/forum/showthread.php?2330121-NASA-Spec3-Build-v2-0

Tom Neely

https://community.drivenasa.com/topic/60919-car-163-build-thread/ 

Edward Higginbothom

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/1995-bmw-325i-racer-trying-to-hit-a-moving-target/140480