Apex Endurance Challenge

Purpose

APEX ENDURANCE CHALLENGE is an inclusive endurance event that aims to make racing enjoyable for all. Teams of 2 are recommended for a shared competitive experience, and no extensive budget or support crew is required. All you need is a car meeting safety specs and a positive attitude. No racing experience, competition license, or medical waivers are necessary. The AEC series promotes safe competition with zero tolerance for car-to-car contact and on-track buffoonery. We expect participants to make mature decisions, ensuring a contact-free experience. Join APEX ENDURANCE CHALLENGE for a fun, safe, and welcoming short endurance racing competition.

1. Registration and Administration

• Visit ApexEndurance.racing for event details, entry fees, deadlines, and race information. Entry limits are set at 15 cars per track mile with a 10% variation based on track design or other factors. All teams and drivers must pre-register online at www.MSREG.com/Apex, and drivers must be registered on MotorsportReg before arriving at the track.
• Refunds and credits: Not available except in the case of event cancellation 21 days before the event itself, subject to a $250 cancellation fee. Cancellations within 21 days of the event date are ineligible for refunds or credits.

1.1 Drivers and Crew

• Participant General Eligibility: All drivers and crew members must be a minimum of 16 years old and in good general health at the time of the event. They must not be under the influence of alcohol, controlled substances, or prescription medications that may impair judgment and coordination. Only individuals over the age of 16 are allowed on the cold side of the pit wall or in garages during hot-track sessions.
• Driver Personal Safety Gear: Drivers must adhere to specified protective gear requirements, including a full-face helmet with visor (face shield) without structural damage, rated Snell SA/SAH-2015 or 2020. Helmets meeting current FIA standards are also permitted. Fire retardant racing suits rated FIA 8856-2000 (or later), or SFI 3.2A/5, or higher are mandatory, with no visible damage. Drivers must wear a current FIA 8858 or SFI 38.1 rated Head and Neck device and carry an in-date certification.
• Driver Eligibility: Apex Endurance Challenge accepts various racing credentials, including no requirement for a competition license in AEC, licenses issued by recognized organizations such as SCCA, NASA, BMWCCA, PCA, Vintage, FIA, IMSA, or other professional sanctioning bodies, as well as competition karting licenses (WKI, IKF, etc.). Completion of nationally recognized racing schools or meeting specific seat time requirements for budget/entry-level endurance series is also accepted.

• HPDE Requirements: Instructors, Time-Trial, and solo participants with passing privileges anywhere on track require CDI approval.
• Minors: Drivers under 18 must submit a racing resume, have a signed parental consent and minor waiver form on file, and a parent or legal guardian must be present at the event at all times.

• Probation/Suspension: Drivers on probation with another series must obtain a waiver from AEC to race. Drivers currently suspended or banned from another series are not eligible for competition in AEC without approval.
• Credentials: AEC reserves the right to demand proof of experience/license credentials at any time.
• Alcohol Policy: Absolutely no open alcoholic beverages are allowed during hot track sessions, including spectator areas, pits, paddock, garages, etc. This rule applies to all individuals, including family, crew, and drivers. Failure to comply will result in immediate removal from the track facility and potential suspension or ban from AEC.

1.2. Vehicle numbers

Vehicle numbers will be supplied by AEC and must be displayed on both sides of the car during events.

1.3. Timing transponders

Each team is required to obtain the proper transponder(s). Rental Transponders are available to eligible teams.

1.4. Entry fees

The Team Captain (team owner) is responsible for paying all the fees and submitting all the proper paperwork. In addition, each driver must register as a driver and be listed as a driver on the owner’s team.

1.5. Unauthorized drivers

If any person is found to have driven a vehicle on course that is not properly registered, all drivers of that vehicle will be subject to disciplinary action. Minimum penalty shall be exclusion from the event. Exclusion from the event may be accompanied by loss of finishing position.

1.6. Team Rules

Each team must declare their team’s name, a class, and a Team Captain (team owner) on their entry form when registering. Each Team Captain is responsible for their team members including safety, rule adherence, and most of all - FUN. If a team name is not declared on their entry form, the team will be viewed as a new independent team.

2. Safety & Tech Specs Defined

Every vehicle must undergo an event/AEC inspection, with a current annual inspection from recognized national racing organizations (SCCA, NASA, WRL, AER, BMWCCA, Porsche CCA, etc.) being highly recommended to expedite the process. A current annual inspection sticker from these organizations should be displayed on the vehicle. The team owner is responsible for ensuring that the vehicle, as well as the safety gear of all drivers and crew members, meets safety standards and AEC regulations. In case of any deviation, the team owner must seek approval from the Race Director or Event Director. 

2.1. Safety Defined

• Race Formats: AEC conducts single-day short endurance races with a maximum duration of 3 hours. Each event includes morning qualifying and practice sessions preceding the race. Specific race times, qualifying formats, fees, and schedules for each race are detailed on the event's page accessible through the AEC website.
• Car-to-Car Contact: AEC adheres to a non-contact racing policy, emphasizing the importance of avoiding contact whenever possible. Drivers are required to maintain racing room at all times, defined as allowing competitors space to maneuver on the racing surface. AEC categorizes contact into three types: Unavoidable Contact, Incidental Contact, and Avoidable Contact. Drivers involved in contact must report to race control before returning to the car, and failure to report may result in indefinite suspension from AEC.

• Unavoidable Contact: Any contact that damages a car or moves a car off its line, but where one or more drivers could not reasonably be expected to avoid the contact.
• Incidental Contact: Minor contact incidental to close quarters racing that leaves minimal damage and/or does not move a car off its line. Includes “racing incidents” - extremely light and inconsequential “racing incidents” meeting the requirements above may not incur a penalty at AEC steward’s sole discretion.
• Avoidable Contact: Repeated contact, contact resulting from reckless or careless driving, or any contact where a driver could have taken reasonable measures to prevent or avoid contact.

• Passing: Safe passing is governed by specific rules, with drivers attempting passes responsible for planning and executing them safely. Faster cars should pass off-line unless given a point-by. Overtaking cars must ensure they are visible to slower traffic, and the use of lights or signals is encouraged. Position determination during passing is clarified, and unsafe maneuvers such as "dive-bombing" and blocking may result in penalties.

• Dive Bombing: Entering a corner very late and without racing position established or forcing a reaction after turn in from the passed car will be considered "Dive-Bombing".
• Blocking: Multiple maneuvers to impede the pass of a vehicle or driving to multiple 'race' lines between corners will be considered "Blocking".
• Emergency Vehicle Etiquete: Racers must be single file & reduce pace when passing EVs.

• Driving Stints: Single-person teams are allowed, but AEC encourages the team aspect of endurance racing, with each team member having at least one "stint" in the vehicle alongside their teammate.
• Video: Functional, forward-facing, and optionally rear-facing cameras are required for all vehicles. Video footage must be stored locally and can be requested by officials at any time for incident review. Teams must present video evidence within 1 hour of the ask to dispute penalties or incidents, ensuring it is properly timestamped and correlated to the incident in question. Failure to provide video evidence will not lead to penalties, but remember, the absence of video evidence after an incident necessitates the reliance on evidence furnished by another team, potentially attributing liability to yours.
• Timing/Scoring: Teams are responsible for the proper installation and operation of their car's transponder. AEC does not accept team-submitted timing in lieu of transponders under any circumstances. Proper transponder operation is crucial for accurate timing and scoring.
• Track Damage: Teams are held responsible for any "track damage" caused during incidents, including barrier damage, oil spills, or fuel spills. Determination of fault lies at the sole discretion of AEC staff, and a $100 administrative fee will be applied to all track damage invoices. Invoices must be paid within 30 days of the incident.
• Compliance: Teams may be required to verify compliance with rules at any time during the event, including making parts available for inspection and providing data for scrutiny. Failure to comply with scrutineering may lead to disqualification. Teams are also expected to pump out vehicle fuel systems post-race if needed.

2.2. Pit & Refuel Requirements

For the safety of all participants, AEC strictly prohibits "Hot Pits" during our events. Vehicles are not allowed to stop on the racing surface or the hot pit for anything other than a mechanical issue or to be towed off-track. Instead, all vehicles must report to their designated paddock or "cold pit" space whenever a pit stop is necessary. A mandatory 10 5-minute stop time will be imposed for pit reasons such as driver changes, fuel stops, mechanical issues, etc., regardless of whether the vehicle is under its own power. The timer begins when the vehicle passes the track entrance/exit into the paddock, and re-entry to the track is only allowed after the allotted 10 5 minutes have passed. Rushing for fuel, driver changes, or addressing mechanical issues on the car is not permitted. Safety checks and work that is required such as spark plug replacement, driver comfort, or anything that does not require the vehicle to be lifted may be done at the hot pit without a 5-minute timer.

Teams are obligated to have two (2) gallons of water and at least one five-pound (5 lb.) or larger BC or ABC rated fire extinguisher, preferably CO2, Halon, Halotron, or Novec 1230. If Dry Chem or Sodium Bicarbonate is used, teams should have vinegar on hand to clean up the mess. Sharing required equipment, such as fire extinguishers, between teams is not allowed, even for the same team. The team owner assumes responsibility for any damages to the track, pits, or paddock.

During fueling stops, where fuel is added to the vehicle, the process must take place off-track, in the paddock, with the vehicle stationary, off, and unoccupied. No work is permitted during fueling for safety reasons. Driver change and only driver changes can happen during fueling.

• Fuel Type: Any fuel type is allowed except for methanol.
• Fuel Storage/Containers: Fuel containers must comply with DOT rules for transport and can be made of HDPE or PET plastic. Metal containers specifically designed for gasoline transport are also acceptable.
• Refueling Jugs: Jugs must be 10 gallons or less, unpressurized, and may use hand or battery-powered pumps from larger containers.
• Spills: Any fuel spills must be reported to race control. The use of absorbent material, litter, or a catch/drip pan is mandatory to keep our event space undamaged.
• Fire Extinguisher Use: Track-positioned fire extinguishers are not readily available for personal use. Reminder: A fire bottle must be on hand meeting the following; at least one five-pound (5 lb.) or larger BC or ABC rated fire extinguisher, preferably CO2, Halon, Halotron, or Novec 1230.
• Fueling: Fueling may only occur when the vehicle is in its paddock space, unoccupied, and turned off. No other work is permitted during fueling.
• Fueler Clothing and Safety Equipment: Properly clothed fuelers must wear a long-sleeve shirt, long pants, and closed-toed shoes.

• If not wearing a race suit, cotton and/or denim are acceptable.
• Safety equipment includes closed-toed shoes and, if refueling, a Snell SA2000 (or newer) rated helmet. Standard crew helmets for auto racing can be used for refueling with the addition of a balaclava.
• A SFI 3.3 or FIA 8856-2000 rated balaclava is required for fueling personnel
• Full driver safety gear is recommended but not required.

• Driver Changes: A Driver change during refueling is permitted. The driver may stay in the car or exit to assist with the next driver after fueling. Alternatively, the driver may assist with refueling but it is not required.
• Additional Vehicle Work: Seat inserts, radios, cameras, adjustments, data cards, etc., must wait until fueling has ceased, and the fueling gear is safely away from the vehicle. No work can be done on the vehicle while fueling is in progress.

2.3. Refueling Equipment

• Fueling equipment in the Apex Endurance Challenge is open, allowing teams flexibility. While certain recommendations are provided, they are not mandatory, and teams can choose equipment that suits their preferences. Apex Endurance Challenge suggests the use of a dry-break valve (male) Redhead with specific dimensions: a 1.75-inch probe with a 1.50-inch hose barb and a 1.25-inch I.D. bore. This dry-break/hose should be connected to an approved 5-gallon container.
• It's important to note that the additional expense of dry-break systems is not required during a 5-minute pit stop. The use of any "quick-fill method" is discouraged, defined as refueling a vehicle using items such as fuel containers other than the standard approved 5-gallon plastic fuel cans, specialized nozzles (aircraft), non-approved "Dry Breaks" (Nextel Cup / IMSA), fuel pumps (of any type), electric power tools, wheels (for any purpose), support stands, pressurized containers, vacuum tank/cells, or other devices considered by the Race Director to be outside the spirit and intent of the rules.
• Fixed-position elevated fueling rigs are prohibited, but the use of hoses, funnels, clamps, PVC & ABS fittings, valves, pipes, threaded connectors, roofing supplies, various plumbing supplies, and similar items found at a local hardware store is generally permitted unless specifically restricted.

2.4. Careless Handling of Fuel

Teams are required to have catch cans under the vehicle during fueling, which must be a minimum of 12 inches round or square, with a 3-inch minimum lip, made of either metal or plastic. Teams must also bring a moisture absorber to keep the paddock and workspace clean should any spill occur. Spills can potentially result in penalties if egregious enough. Note that a small drip during refueling will not constitute careless handling of fuel. AEC officials will use their discretion to determine instances of careless handling. Please make sure your team has an adequate amount of absorbent for any chemical spills. Careless handling of fuel can occur at any time, not just during your 5-minute cold stop.

2.5. Pit speed limit

The speed limit in the pit lane is 25 mph and the paddock is 15 mph. Unless otherwise indicated, the speed limit is in force from cones laid on the entry to hot pit and exit. AEC reserves the right to move cones as needed to enforce safety in the pit and paddock.

2.6. Tires

You can use any street tire (DOT) that shows treadwear 180 (or greater) on the sidewall. Any car using a lower treadwear tire, competition tire or slick will forfeit their chance for placement in their class.

• Tire Width: Any tire width is welcome as long as the top of the tire may not protrude from the fender opening/flare as viewed from the top. All tires must be commercially available: prototype tires or those not available to the public for purchase will not be permitted. Chemical agents used to “soften” a tire or modify the properties of the rubber are not permitted and may be subject to disqualification.

3. Classing and Car Prep

Closed-wheel racecars meeting safety equipment requirements and having a current BMW, WRL, NASA annual inspection sticker may be considered for entry, subject to event administration and on-site tech approval.

• Car Eligibility: AEC classes welcome most mass-produced passenger cars eligible for registration and use on public streets. Vehicles with production race car status lacking legal VIN numbers are permissible but may require petitioning for inclusion in respective classes. The decision to include these vehicles rests solely with AEC. To petition for inclusion, contact info@apexhpde.com.
• Width: No part of the car should extend beyond the widest point of the stock side mirrors or the widest point of the stock body plus 6 inches total, whichever is less.
• Firewalls: Firewalls must be present between the fuel cell/tank/fuel filler neck and the driver, as well as between the engine and driver. Any holes or gaps 1/4 inch in diameter or larger must be securely closed or sealed.
• Lighting: Cars must have a minimum of two bright functional red brake lights. It is recommended to retain and keep operational the OEM brake running lights. Headlights can be OEM or aftermarket, with mounting points no higher than the base of the windshield.

• General Requirements:

1. MASTER SWITCH: The switch location is flexible, provided it can be easily located and deactivated by the driver, crew member, or safety worker. It must isolate the battery from all circuits and interrupt the ignition circuit. Positive terminals of the battery and switch must be insulated. A "Master Switch" decal with the universal "lightning bolt" and the word "OFF" must be visibly displayed on the exterior as close to the switch as possible.
2. BATTERY: Secure battery mounting with a clamp or hold-down is mandatory. Ratchet straps and camlock straps are not allowed. The positive terminal must be insulated. If located in the cockpit, batteries other than AGM or LiFePO4 must be enclosed in a battery box (Marine style or similar).
3. HARNESS: Installation and use of 5, 6, or 7-point racing harnesses with a current FIA or SFI rating are required, following manufacturer specifications. Webbing must not be stretched, cut, frayed, or deteriorated from weather. Sub belts and lap belts must be attached to structural members or bolted through the floor with 3” Dia. (minimum) backing washers or plates. Shoulder straps must be securely fastened to the harness bar.
4. WINDOW NET: Seats without a Head Restraint design necessitate a center net running from the rear bar to the center dash.
5. SEAT: A current FIA/SFI, one-piece seat with a rigid shell, specifically designed for auto racing, is compulsory. The seat must be securely mounted at a minimum of four points at the base. If bolting through the floor, 3” Dia. (min) washers or backing plates are required. Seats lacking a current FIA rating must have a seat back brace if the seat back is more than 3” from the harness bar for any driver. The back brace can be adjustable and must not pose a risk to the driver by its design or installation.
6. OEM SAFETY: Ignition and steering locks must be disabled, and airbags must be removed.
7. MIRRORS: Each car must have one functional side-view mirror on each side and one interior rearview mirror.
8. GENERAL PREP: Cars may undergo a "freshening" process with OEM/equivalent drivetrain internals, bushings, bearings, etc., to ensure they are generally safe and reliable as when new. Owners are encouraged to make their cars look presentable. AEC reserves the right to refuse any vehicle that does not meet these requirements.
9. CHASSIS: The chassis must be structurally sound, with all body panels in place. Aftermarket panels and body kits are acceptable, but alternate materials must resemble OE panels.
10. GLASS: Except for mirrors and headlights, any glass used must be OEM (laminate or tempered). Front and rear glass may be replaced with polycarbonate/lexan. Front windows will be removed or fully down during the race. Windshields should be free of large cracks or damage that could compromise integrity. Minor damage may be allowed at the discretion of AEC. Cars with windshield damage compromising driver protection may not be allowed to continue.

3.1 The official classes are APEX ENDURANCE 1, 2, 3, M.

Any mass-produced car offered for sale and operation on public roads. AE-class cars are subject to the Basic Prep Rules and Modifiers in below.

Apex Endurance 1 (AE1) = “Adjusted Wt/HP Ratio” equal to, or greater than, 10.00:1 or below

Apex Endurance 2 (AE2) = “Adjusted Wt/HP Ratio” equal to, or greater than, 12.00:1 or below

Apex Endurance 3 (AE3) = “Adjusted Wt/HP Ratio” equal to, or greater than, 15.50:1 or below

Apex Endurance M (AEM) = All Spec Miata Rules will be followed according to NASA SM rules:

https://nasa-assets.s3.amazonaws.com/document/document/23772/2024_Spec_Miata_Rules.pdf

3.2 Calculating Power

To calculate the Power-to-Weight Ratio (PWR), the car's peak power is divided by the weight of the car plus a 200 lbs driver ballast added for all vehicles. The weight will be measured by AEC at tech at the track with a full fuel tank, no cool shirt water, and no undisclosed ballast. The resulting value is rounded to the nearest tenth, with .05 rounding up. This calculated value represents the car's Base Power-to-Weight Ratio (Base PWR).

For modifications not allowed in the Basic Modification Rules below, a modifier value is assigned based on the tables in section B of rule 3.4. This modifier is then applied to the Base PWR to determine the Adjusted Power-to-Weight Ratio (Adjusted PWR), which is used to determine the car's class.

Example:   ( [WEIGHT + 200] / [POWER] ) + [MODIFIERS] = PWR

                           ( 2350lb / 150 ) + ( -0.2 ) = 15.5 PWR

3.3 Cage Rules

Section A - General Principles

Professionally designed and constructed roll cages are strongly recommended, and it is advised that individuals without proper training or skills should not attempt to build them.

Professionally manufactured bolt-in cages are permitted, provided they are installed using the tools and hardware specified by the manufacturer and meet the design criteria outlined in Section B. (Bolt-together cages are prohibited, with an exception for non-steel chassis, which may affix the roll cage using mounting plates of .188" or thicker steel, supported by 4 or more 5/16" or 8mm bolts, grade 8 or higher per mounting plate. All tubing junctions must be fully welded.)

Welds must exhibit professional quality, providing 360 degrees around every tube joint with full penetration. The minimum tubing size is determined by the car's weight, and all tubing must be seamless mild steel or DOM (ERW is not acceptable unless a waiver is granted for an existing cage).

For cars under 2500 lbs: 1.50" x 0.095"

For cars 2501 lbs and over: 1.50" x 0.120" or 1.75" x 0.095"

Tubing should be Rotary Drawn or Mandrel Bent and properly notched with appropriate tools, ensuring bends have a radius no less than 3 times the outside diameter of the tubing and show no signs of crimping, stretching, or potential failure.

Any cuts made in a firewall to accommodate tubing must be re-sealed once the tubing is installed. The use of gussets to reinforce connecting points is allowed. Any part of the completed roll cage that may be contacted by the driver's helmet, body, or limbs must be padded with roll bar padding.

Vehicles not meeting these criteria but carrying a FIA homologation on the safety cell may request approval by emailing info@apexhpde.com.

Section B - Roll Cage Design

1. Main Hoop must be a single, continuous length of tubing with no more than 4 bends and should follow the B pillars and roofline as closely as possible with a rake of no more than 15 degrees off vertical. The Main Hoop will be tall enough so that any driver's helmet does not extend above a line connecting the centerlines of the Front Hoop and Main Hoop.
2. A diagonal brace will be added in the same plane as the Main Hoop, with one end connecting at lower right of the Main Hoop at the mounting plate or as close as possible, and the other end connecting to the top left (horizontal) of the Main Hoop within 12" of the bend nearest the driver's head
3. The Main Hoop will be braced with two uncut, continuous tubes extending rearward from the top corners (bends) of the Main Hoop, or within 6" thereof, running straight to the floor, factory cross member or strut/shock towers. The rearmost point of the rear bracing must not terminate on another tube. Rear bracing will not have any bends and should be at a 30-60 degree angle to the plane of the Main Hoop.
4. Forward section of the main cage may be one of three configurations:

1. Side Hoops (aka "Forward Hoops"): Tubes extending forward from the top corners (bends) of the Main Hoop and down to the front floor, following the roof line and a-pillars as closely as possible, each with no more than 2 bends, and both connected by a tube running as close to the top of the windshield as possible. (SCCA Production cages that do not follow the original roof line may qualify, petition the officials before the race to gain approval), or;
2. Halo: A single tube bent into a "halo" that extends forward from either corner of the Main Hoop in a horizontal plane to the top of the windshield and follows the roof line as closely as possible. The front of the halo will be supported from the floor/sill by a continuous section of tubing that follows the A-pillar as closely as possible from each front corner of the halo to the floor.
3. Front Hoop: A single, continuous length of tubing with no more than 4 bends, which should follow the A- pillars and roofline along the top of the windshield as closely as possible, mounted on either side to a floor plate or sill. The front Hoop and Main Hoop will be connected together on either side by tubing running from the top corners of each hoop and following the roof line as closely as possible.

5. Door Bars: A minimum of two door bars are required on the driver's side, x-bars are acceptable. Bars must be placed to protect the driver in the event of a side impact. Door bars may be bent to push into the door cavity, but S-bends are prohibited* on new cage builds (2014 or later) unless the car has a valid log book from a club racing or higher-level organization and are approved by AEC officials. A minimum of one door bar is required on the passenger side. If you are unsure, submit pictures and descriptions to AEC BEFORE you show up to race *S-bend bars may be submitted for exception to: info@apexhpde.com in cases where they are the only option..
6. Dash bar: A dash bar running horizontally between the front hoop a-pillar bars, and at the height of the original dash is required. Factory dash bars may be approved at AEC discretion - email info@apexhpde.com for approval.
7. Harness Bar: A horizontal bar between the left down tube of the Main Hoop and the Diagonal Bar may be installed for shoulder harness strap mounting, at a height recommended by the harness manufacturer. Harness bar may have bends to accommodate aft seat travel
8. Seat Mount: A seat mount tube or tubes mounting the seat to the roll cage is highly encouraged, and does not count toward cage attachment points

Section C - Mounting points

1. Cage must be mounted to the floor, frame, factory cross member, towers and/or sill plates at a minimum of 6 points (2 each at the Main Hoop, Rear Braces and Front Hoop). 2 additional mounting points may be used at the Front Hoop to the firewall or front wheel wells
2. The use of Body Tabs is open, but tubes added for no other reason than to increase chassis rigidity may be disallowed or penalized at the officials' discretion
3. Mounting plates must be at least 16 square inches at 0.080" thick and must be welded completely around the perimeter. If bolted in, the plate must be 3/16" thick minimum, bolted at a minimum of three points with Grade 5 hardware

Final Authority on whether your cage passes a safety inspection or not lies solely and completely with the race officials.. If the cage is deemed unsafe at AEC sole discretion it will not be allowed to race. For example - if there are missing bars, missing/inconsistent welds, or any other issue that presents a safety hazard, the car cannot be allowed on track. When in doubt, submit pictures and descriptions before you show up to an event.

3.4 Modifiers

The following values will be deducted from a car’s PWR. The value on a given line is for EACH of the items in the list. Any missing items or gray areas will be dealt with at the AEC Officials’ discretion and must be disclosed on the car’s disclosure worksheet.

Section A - BASIC MODIFICATION RULES

1. Open, Allowed or “Free” Modifications: All cars are allowed to make the following modifications to build reliable, cost-effective, and competitive cars. NOTE: OE-Originally equipped. OEM - Original Equipment Manufacturer.

1. Engine: Open. Engine Modifications are addressed by dyno testing as described.
2. Brakes: Stock master cylinder or OE equivalent. Caliper/rotor may be upgraded to any caliper/rotor offered in a USDM variant of the same make/model/generation. OE Calipers or non-OE calipers with 4 or fewer pistons, single piece metallic rotors, and pads are open. Proportioning valves are allowed.
3. ABS: Any ABS system from a mass-produced, non-motorsports specific vehicle is allowed. Must retain original programming.
4. Springs: Metallic springs open, may heat or cut.
5. Shocks/Struts: Shocks, struts, and coil overs with non-adjustable dampening characteristics are allowed. Adjustable shocks with adjustment knobs removed are still classified as adjustable and shall take the associated modifier per the modifier table.
6. Other Suspension: Sway bars and Panhard bars/Watt’s linkage open. Camber and toe adjustment through camber plates; eccentric bolts, bushings, ball joints or adjustable control arms are allowed if these components attach to the OE mounting point(s) and serve no other purpose. Adding reinforcement to suspension attachment points to gain durability is allowed.
7. Bushings: Open
8. Factory Aero: Any factory, OE aero that was sold for the make/model/submodel of the chassis is open. Added aero items specific to factory prepared race cars, even if it is the same model, will be assessed as aftermarket aero.
9. Wheels: Must affix to hubs via 4 or more “lugs” and lug nuts. Centerlock wheels are not permitted.
10. Tires: DOT approved with tread wear (UTQG) rating of 180 or higher.
11. Powertrain Cooling: Transmission, engine and other oil coolers allowed.
12. Limited Slip Differential: Open. Factory and aftermarket limited slip differentials are allowed.
13. Exhaust: Open, must meet any sound restrictions listed in Race-specific information and/or supplementals. Affixed to OE mounting places only.
14. Weight reduction: Open, but exterior skin, and chassis structural integrity must be retained. Fenders, hoods, trunk lids, firewalls, floors, and inner wheel wells must remain intact. Alternate bodies must be approved.
15. Driver comfort/information: Cooling, gauges, control devices, data and telemetry systems are open.

2. Additional Modifications: Modifications not listed in Section B below are allowed, but must be fully disclosed and may require a classing modifier as listed below based on the discretion of the Officials after a thorough inspection of the number and extent of the additional modifications.
3. Engine and Drivetrain Swaps: Engine/drivetrain swaps are allowed and must be fully disclosed.
4. Multiple / Switchable tunes: Any device, switch, software program, boost controller, etc. that alters ECU or other engine parameters to change tunes, whether mechanical or electrical, shall not be installed within reach of the driver. If one exists within reach of the driver it must be disclosed, disabled and inspected by tech officials. Tunes that change based on vehicle parameters like boost-by-gear, wheel speed, etc are not permitted. Deliberate tuning to change tunes on-the-fly or subvert the intent of the switchable tune rule will result in immediate DQ up to series ban. Under hood manual boost controllers must be disclosed and will be taped with tamper-evident tape prior to the event. Compliance will be verified by black box, radar, physical inspection or other means at AEC’s official’s discretion. Power sticks, or any empty port that can accept changeable ECU maps must be inspected and security taped by AEC officials. TEAMS MUST SELF-REPORT THESE FOR TAPE BEFORE GOING ON TRACK.
5. Failure to Disclose: Any team that does not fully disclose modifications outside of the scope of this section may be subject to disqualification. Teams that blatantly subvert the classing rules may be banned from competing in future AEC events.

Section B - GRADED MODIFICATION RULES

AE AERO

AE BRAKES

AE SUSPENSION

AE TRANSMISSION / CLUTCH

3.5 Ballast

Ballast Up to three hundred (300) lbs. of added ballast is permitted. All ballast must be of solid material (no fluids or shot pellets), safely secured in any location on the vehicle not disallowed by AEC safety technical inspectors.

3.6 Air Jacks / jacking systems

The use of any device other than a manual jack(s) or a manually operated hydraulic jack to raise the vehicle during competition is prohibited.

3.7 Fire Suppression

Fire suppression systems must adhere to FIA technical list #16 or #52, or SFI 17.1 standards. Regular servicing by an authorized center is mandatory every two years to ensure compliance with testing standards. Note that FIA systems have a 10-year cylinder life, while SFI systems have a 6-year cylinder life.

An easily accessible activation point must be within the driver's reach when seated with tightened belts. It's highly recommended to have an external activation point for safety personnel, marked with a "E" label. Ideally, this location should be close to the master switch/battery/power kill switch, marked with a triangle lightning bolt label.

To withstand heavy impacts, mount the fire suppression system securely. It's advised to place all components within the main crash structure to prevent removal or damage during an impact. Follow the manufacturer's installation instructions without modifications, and ensure the activation mechanisms function correctly. Check that cables move freely, and for electrical systems, the power pack should include a battery and circuit check function.

Before hitting the track, ensure all safety pins are removed, valves are open, or electrical system power packs are switched to the ON/Active position. For larger cockpit cars with FIA technical list #16 systems, a 3kg (6.6lbs) or 3L (approximately 6lbs) system or larger is recommended. In cases where FIA Technical list #52 systems are not required, such as certain GT class rules, a 10lb system is suitable for SFI 17.1 compliance.

4. Format

4.1. Grid

Pre-grid closes 5 minutes before the pace car leaves. Late vehicles must start in the back of the entire field or may be held to start from pit lane at the discretion of the Steward or Race Director.

4.2. Race length

The effective race duration may fluctuate and conclude either at the scheduled time of day or after a specified duration, not exceeding 3 hours. The Race Director will ascertain the precise length and end time before the race commences. Nevertheless, the Race Director retains the authority to modify the race duration in the event of unforeseen circumstances. Competitors are accountable for obtaining relevant information on the race duration from the Race Director. The official clock initiates when the pace vehicle embarks on the warm-up lap(s), unless otherwise specified for a particular event.

4.3. Race finish

The leading racer will receive the checkered flag at the finish flag stand promptly after the official race time expires. Typically, the Starter provides a "last lap" flag signal, though it may not always be the case. It's important to note that finish lines may not always be directly aligned with the finish flag stand.

4.4. Starting order

• The Race Director will select a starting method for establishing the starting order. The methods are at the discretion of the race director and involve gridding based on a qualifying session (or reverse), vehicle number, etc.
• The starting method, as determined by the Race Director, is not open to questioning or dispute. However, if there is an error in the assigned starting position based on the chosen method, a competitor or team’s representative should inform the Race Director.
• Substituted vehicles: substitute vehicles are not allowed in AEC Endurance events.

4.5. Leaving cold pits

Vehicles may be held from leaving the cold pits when the pace vehicle is on track. The stewards may hold a vehicle on grid until the pack comes by, if they estimate that the vehicle cannot catch the end of the pack before reaching the incident.

4.6. Red flag

During a red-flag situation, all activities on vehicles in the cold pits, including refueling, are allowed. Cars not on the track and involved in a time-controlled apron stop during a red flag will be detained for the elapsed time of the red flag condition in addition to the 5:00-minute restriction. For example, a 3-minute red flag will result in an 8:00-minute hold time before re-entry. Please note that while you may return from cold pit to the grid for a restart, you will not be released back onto the track until the green flag is displayed at the starter’s stand.

4.7. Repair on cold pit

Vehicles shall have at least one jack stand under a vehicle if a crewmember(s) is working under the vehicle.

4.8. Full-course yellow

Drivers may return to grid and eventually to the track during yellow flags. Any team already in the cold pit during a full-course yellow may continue working on their vehicle. Any exit of the track during yellow flags will be subject to the 5-minute cold pit rule.

5. Scoring

5.1. Finishing Position

The final placement will be decided based on the overall laps accomplished, regardless of whether the vehicle is operational at the race's conclusion. In the event that two vehicles have an equal number of laps completed, the one that crosses the finish line first will be ranked higher. If two vehicles experience breakdowns on the same lap, the vehicle that covered the greatest distance since the green flag will be granted the superior finishing position. The term "distance" is measured from the starting line and excludes the grid's length or variations in grid starting positions.

5.2. Provisional results

Provisional results may be announced at the track, coinciding with the trophy presentation; however, these results are not considered official until marked as such and published by the AEC director.

Impound procedures dictate that podium cars from each class, along with the fourth position, will be impounded after each race at the discretion of the Race Steward. AEC officials and competitors will conduct inspections and weigh-ins for a duration determined by race officials.

Podium cars are required to report directly to impound upon exiting the track, and failure to comply may result in disqualification. During impound, "Parc-ferme" rules apply, prohibiting teams from opening doors, trunk, hood, or touching the vehicle for any reason without permission and supervision from an AEC official.

Impounded cars will be weighed without driver but adding the flat 200 lbs driver weight, and the weight will be verified against their submitted entry. The vehicle must meet the minimum weight requirement for its class, based on POWER and modifications.

Fuel capacity checks may be conducted through pump-out, and teams are responsible for providing means to completely empty the fuel system into a fuel container. Teams are encouraged to add a quick-disconnect under the hood to expedite fuel pump-outs.

Fuel density will be determined by weighing one gallon of the team's fuel in a certified container, and fuel capacity will be assessed by filling the car under AEC supervision and pumping the system dry into weighed jugs.

Impounded cars may undergo POWER verification by dyno, operated by an AEC-appointed official. Teams must comply with the dyno verification process, and failure to do so may result in disqualification.

All podium finishing cars must furnish a printed copy of the disclosure worksheet including dyno results for review by officials and competitors in impound. Failure to provide this may lead to disqualification.

Competitors have the right to protest a podium car for any undisclosed modification or major rule violation. Protests must be submitted through a form along with a fee, which will be refunded if the protest is upheld. The protesting party can remain anonymous, and the AEC protest fee is $200.

5.4. Penalty Laps

In cases where vehicles incur penalty laps affecting finishing calculations and a tie arises, the tiebreaker is determined by the fastest single lap during the actual race, excluding practice or qualifying sessions. Penalties, though undesirable, are implemented by event officials when necessary, and they may result in one of several unpleasant experiences. AEC employs one of two basic penalty systems:

1. Post-race penalties involve subtracting laps after the race.
2. Timed stop-and-go penalties are assigned for each infraction. Any penalty specifying "laps" can be applied to the "timed stop-and-go" system (No. 2) by replacing "lap(s)" with "minute(s)" (e.g., a 5-lap penalty translates to a 5-minute penalty if using system No. 2).

Note: If system No. 2 is employed, and it is too late in the race to issue the full-time penalty, the race results will be adjusted to penalize the team with the assigned time penalty plus an additional 30 seconds.