Purpose and Introduction
The intent of Gridlife Cup is to allow competition of production based vehicles focusing on fun, competitive racing, in a relaxed environment with an extremely tuner friendly ruleset that allows personal customization of the car to the tastes of the owner. Gridlife Cup features a single class with a simple, open ruleset designed to attract as much vehicle variety as possible while hopefully maintaining large, competitive fields. Gridlife Cup also focuses on promoting club racing to a younger generation, heightening the spectator experience and celebrating motorsports car culture.
The general philosophy of the class is based on a target competition weight (with driver) per average wheel horsepower ratio. The target ratio is 13.0 lbs/WHP(wheel horsepower). This ratio can be raised or lowered using a points based system that accounts for certain vehicle characteristics and modifications that alter the performance of the vehicle. Vehicles with a ratio greater than 13.0 will have better handling while a ratio less than 13.0 will have better straight line speed. The rules of Gridlife Cup are designed to be inclusive while keeping the competitiveness of all vehicles as equal as possible. The broad nature of difference in potential cars that fit this class might lead to some cars being better at certain tracks, but the goal is similar potential laptimes, and an interesting and challenging race environment.
The ratio and points system is designed to keep the speed of vehicles similar to popular entry level tuner classes. Vehicles already built to similar classes in other sanctioning bodies should fit into Gridlife Cup easily with minor modifications. Vehicles built to classes with a much larger difference in speed have plenty of options to adjust their ratio using the points system. The ruleset is designed to be open with many options and tiers to attract a wide range of pre-built vehicles and also encourage new, unique builds for the class.
Vehicles used in Gridlife Cup must be production vehicles offered for sale to the public through the manufacturer’s distribution channels. Non-production vehicles such as kit cars, purpose built tube frame racecars, or open wheel vehicles are not allowed unless pre-approved within the rules or approved on a case by case basis.
The modification points system and ruleset will be closely monitored as more Gridlife Cup races are hosted, and will continue to be adjusted and fine-tuned to maintain competitiveness of the competition. Please stay updated and adjust your ratio accordingly. Drivers must submit completed car calculator forms via email to
before events, or bring printed copies to events.
- Driver must have a valid competition license or racing allowance no older than 5 years old from the approved sanctioning bodies below;
- SCCA Competition license
- NASA Competition license
- PCA, BMWCCA
- AER, WRL
- May be approved on a case by case basis if the following are met;
- Novice license from any above
- Wheel to wheel experience including Champ, Lemons (records and documentation needed)
- Experienced Time Attack Competitor, with written approval from motorsports director.
- Must adhere to all safety and conduct regulations for drivers outlined in the GTCR (Gridlife Trackday and Competition Rules) found under the Drivers’ tab on Grid.life, under Rules and Tech forms.
- Drivers must submit completed car calculator and driver experience forms via email to
before events, or bring printed copies to events.
- Any production vehicle of any year that is sold in any market with at least 300 produced.
- Non production vehicles such as kit cars, or tube chassis vehicles conforming to classes in other sanctioning bodies that have not been pre-approved are allowed only on a case by case basis if speed is similar. Additional points may be added to the ratio.
- Must adhere to all safety and conduct regulations for cars outlined in the GTCR (Gridlife Trackday and Competition Rules) found under the Drivers’ tab on Grid.life, under Rules and Tech forms.
- Standard roof line must be maintained on all non-convertibles.
- Any OEM/Replica OEM-style hardtops of any material are allowed on convertibles. Leftover OEM convertible parts may be removed.
- Aftermarket hardtops or coupe conversions that alter roof lines (ex. S2000 Spoon hardtop) will have points added to the ratio. E1: +0.5
- Entire windshield removal or modification of the A-Pillar will have points added to the ratio. E1: +0.5
- Fenders and quarter panels can be of any material. Fenders lips may be rolled or cut. The exterior of the fender may be pulled and/or spaced out.
- Fender linings may be modified or removed.
- Fender opening shape must be maintained and the heights of the fender openings may not be altered.
- Fender vents or louvers are allowed solely for the purpose of reducing wheel well pressure.
- Tire tread/ contact patch must be under the fender and not visible when viewed from directly above the tire.
- Fender flares and wide body kits are allowed solely for the purpose of fitting wider wheels and tires. Original fender opening shape (when viewed from horizontal perspective, IE-side view) must be maintained. Non visible sections of the OEM fenders behind the flares/body kit may be cut and removed.
- Wide body kits may not have any winglets, canards, or any elements that help increase downforce.
- All attached body work must be firmly attached and suitable for track use.
- Standard door shape must be maintained.
- Doors can be of any material.
- Door internals including crash beam may be gutted or modified with “nascar style” protruding door bars.
- It is mandatory that all doors can be opened from both inside and outside.
- Mirrors are free and can be relocated to inside the car but one per side is required.
- Front bumpers can be of any material.
- OEM bumpers can be used from other trims within specific vehicle model
- Aftermarket front bumper(covers) are allowed and worth no points as long as they satisfy the following;
- May not have canards/winglets molded into it.
- Any item that is molded into the fascia that increases downforce such as winglets, canards, dive planes, etc. are not allowed.
- If any feature on the lower portion of the bumper that extends past its immediate surroundings and acts as a splitter, will be classified as a splitter and will have points added to the ratio. C2: +0.4
- Modification of front bumpers is allowed for brake ducting, radiator cooling and other cooling/ducting purposes.
- Aftermarket lip kits are allowed on OEM and aftermarket bumpers;
- If any feature on the lower portion of the lip extends past its immediate surroundings and acts as a splitter, will be classified as a splitter and will have points added to the ratio. C2: +0.4
- Air dams are allowed;
- Must be vertical (+ or - 5 degrees maximum, for material deflection. intent should be full vertical)
- Can have any sized openings for brake ducting, radiator cooling and other cooling/ducting purposes.
- Bumper hidden behind the air dam may be cut and removed.
- Under trays are allowed;
- May close out the underbody from the leading edge of the front bumper the centerline of the front wheels
- May not protrude past the bumper otherwise it will be classified as a front splitter and points will be assessed. C2: +0.4
- Dive planes/canards/winglets are not allowed
- OEM crash beam may be modified or replaced with an alternative option. Using a crash beam is highly recommended to prevent frame damage.
- Grilles and other bumper openings may be blocked off and sealed for regulating air flow.
- Rear Bumpers can be of any material.
- OEM bumpers can be used from other trims within your model.
- Diffusers are not allowed unless part of the OEM bumpers.
- Aftermarket rear bumper are allowed and worth no points as long as they satisfy the following;
- May not have dive planes/canards/winglets molded into it.
- May not have a diffuser.
- Bottom of the bumper must be below the location of the OEM crash beam
- Modification to the bumper is allowed but only to the section below the location of the OEM crash beam, no higher. This lower section may be completely cut off.
- OEM crash beam may be modified or replaced with an alternative option. Using a crash beam is highly recommended to prevent frame or unibody damage.
- OEM side skirts may be modified or completely removed.
- Aftermarket sides skirts are allowed and worth no points as long as they satisfy the following;
- May not have dive planes/canards/winglets molded into it.
- Does not extend any higher than the OEM side skirt
- No lower than 3” from the ground, and not more than 1.5’’ outward from widest point of bodywork above them.
- May not extend more than 4” inward from oem pinchweld
- Holes are permitted only for use of an exhaust exit
Hoods and Trunks
- Hoods may be replaced to any aftermarket unit of any material.
- Hoods may be modified, cut and/or vented to aid with engine bay cooling.
- Hoods may be modified and or cut to increase engine clearance if needed (ex. J32 Integra). Hood risers up to 1” max are also allowed.
- Any hood and trunk fasteners are allowed as long as the hood is fastened adequately for potential speed.
- Rear trunks may be gutted and/or replaced with any material as long as original shape is maintained (not including license plate frame).
- Windshield may be replaced with ¼” thick Lexan. Lexan should be rigidity attached using metal fasteners. If only adhesive is used, windshield tabs or bracing is recommended.
- Rear door glass, rear quarter glass and rear window may be replaced with ⅛” Lexan.
- Sunroof may be removed and replaced with a plug.
- Front driver and passenger door glass must be removed or lowered at all times while on track.
- Window frames and channels on front doors may be removed.
- NACA ducts are allowed on side windows only for the purpose of cooling the driver.
Headlights and Taillights
- Headlights and taillights may be replaced with aftermarket units
- Headlight and taillight sections may be removed and replaced with block off plates resembling the original shape
- Openings are allowed in the headlights solely for the purpose of ducting air to the intake.
- Glass headlights and tail lights must be covered in vinyl or tape.
- One brake light per side is required.
- No Splitters (C1: 0.0)
- Any oem bumpers, air dams, aftermarket front lips or aftermarket front bumpers without a splitter or splitter elements. Please see section 4.d. for more details.
Splitters (C2: +0.4)
- A front splitter may be used with an OEM or aftermarket front bumper and will have points added to the ratio. C2: +0.4
- Splitters may extend no further than 4” past the furthest point of the bumper body lines when viewed from above and no further rearward of the center point of the front wheels.
- Bottom of the splitter must be flat with no vertical deviations and has an allowable angle of attack of +/- 5 degrees from horizontal.
OEM Aero (C3: 0.0)
- Any OEM or OEM-style device such as a wing, spoiler, deck lid, hatch duck bill etc. OEM aero can be transferred to any trim of the same model.
- Active OEM aero is not allowed.
Wing Stage 1 (C4: +0.3)
- A single element rear wing that does not exceed a height of 6” below the highest point of the roof line. For hatchbacks or wagons, the wing must not exceed a height of 4” above the highest point of the roof line.
- Wing assembly may be no wider than a maximum of 48.25 inches
- Maximum chord length of 8.5”.
- Wing end plates must not exceed 64.0 square inches each.
- The trailing edge of the rear wing may be mounted no further rearward than the center of the rearmost part approved bodywork.
- Active aero is not allowed
Wing Stage 2 (C5: +0.4)
- Single element rear wing that does not exceed a height of 8” above the highest point of the roof line,
- Wing assembly no greater than the vehicle’s body width (not including flairs or widebody),
- Chord length is free,
- End plates no greater than 144 square inches each.
- Active aero is not allowed.
Wheel and Tires
- Select a tire from one of the 3 categories below;
- DOT Slicks, Hoosier A7/R7/SM7/H20, BFG R1S/R1, Hankook Z214 or any 40tw. (B1: +0.5)
- Semi Slick, Toyo RR, Maxxis or any 60tw-140tw. (B2: +0.2)
- Street Tire, 200tw or greater. (B3: 0.0)
- Select a tire width from one of the 4 categories below
- 205 or smaller (B4: -1.2)
- 215 – 225 (B5: -1.0)
- 235 – 245 (B6: -0.7)
- 250 – 275 (B7: -0.3)
- Points are assessed based on the widest tire used on a vehicle.
- Must be aluminum alloy.
- Widths and diameters are free.
- Pedal systems are free and non stock systems must be adequately constructed.
- Brake lines, proportioning valves, master cylinders, brake boosters are free.
- Drum to disc conversions are free.
- Brake ducting and water cooling is free.
- Handbrake systems can be removed.
- Aftermarket calipers and mounting location are free.
- Aftermarket 1 or 2 piece rotors are allowed but must be of ferrous material and located in the original location.
- Vehicles not using ABS will be assessed less points. Vehicles equipped with ABS may remove the entire system or disable the system by pulling a fuse is which must be verified. (D1: -0.2)
- The OEM firewall must remain intact to protect the cockpit from flames within the engine compartment. Any holes in the firewall must be sealed with metal (no holes larger than 1/2 ‘’ in diameter can be sealed with metallic tape, larger holes must be sealed with sheet metal ). The firewall is to remain OEM and un modified unless clearance is needed for an engine swap or for roll cage tubing to shock towers or strut towers. The firewall can be altered up to 10” from its original location for engine swap clearance only.
- The OEM frame rails and/or main unibody structure between the front and rear wheels shall remain unmodified and in the original location. stich/seam welding is allowed, as is boxing and reinforcing of Frame rails in non unibody applications.
- The transmission tunnel, floor pan, rocker panels and fender wells shall remain generally unmodified and in the original location. Modifications to fit seats or larger mufflers may be made to exhaust or transmission tunnels and seat-area of floorpan, but must serve no other purpose.
- The strut/shock towers shall remain unmodified and in the original location. Bracing and strengthening the strut/shock towers is allowed.
- On non-convertibles, the A-pillars shall remain unmodified and in the original location.
- On convertibles, is it permitted to remove the front windshield and A-Pillars but points will be assessed. (E1: +0.5)
- Front and rear subframes must be installed in the OEM location. It is permitted to replace the subframes with updated or backdated OEM replacement alternatives as long as they are a direct fit and can be installed without modification. Subframe bracing and strengthening is allowed. Modifying the suspension pickup points is not allowed.
Suspension and Steering
- Suspension components shall remain OEM unless noted below.
- It is permitted to update/backdate or replace suspension components including spindle/knuckle, hubs, control arms, etc. with alternatives as long as they are sourced from the same manufacture and can be installed without modification to the original locations. These components may be reinforced.
- Suspension shocks, struts, top hats, coilover conversions, springs and sway bars are free.
- Adjustment to any suspension component by the driver during a session is not allowed.
- Any form of camber/caster/toe adjustment methods including top-hats, camber plates, alternate upper control arms, adjustable upper ball joints, eccentric bolts, shims or slotting are allowed as long as they attach to the OEM locations.
- Replacing bushings with spherical bearings are permitted.
- Changing suspension pickup points on the chassis or subframe is not allowed.
- Cars equipped with front MacPherson strut type suspension are assessed less points. (E2: -0.3)
- Lower ball joints are free
- Lower control arms may be replaced with aftermarket alternatives as long as suspension mounting points (excluding sway bar mounting points) on the aftermarket arms remain in the same location as the OEM part.
- Front and rear tie rods/toe links are free.
- The steering rack shall remain OEM and in the original location. It is permitted to raise or lower the steering rack to correct bump steer. It is permitted to modify the steering rack to alter lock-lock ratio. It is permitted to swap the steering rack with an OEM alternative. The power steering system may be modified.
Engines & Transmission Swaps
- Any engine swap is allowed from a production vehicle of any manufacturer. (ex. K20 swap in a Miata).
- The engine must be in the similar location of the originally installed engine but orientation may be altered.
- Transmission options to complete the swap include the following;
- Any OEM transmission from the chassis manufacturer. (ex. K20 swap in a Miata using any Mazda trans),
- Only the OEM transmission connected from factory to the chosen engine swap. (ex. F20 swap in a Miata using an F20 trans),
- All other OEM and aftermarket transmissions but will be assessed additional points. (ex. K20 swap in a Miata using a BMW or sequential trans). (F4: +0.5)
- Bellhousing adapter plates to fit transmission to different engines are allowed.
- Any differential housing may be used.
- Any OEM gear sets (or aftermarket replacement gear sets identical in spec to the OEM gear and ratio) from the transmission selected may be used if they fit without modification.
- Any final drive ratio is permitted if it fits without modification.
- Differentials are free.
- Differential and transmission coolers are free.
- The following transmission modification are assessed additional points. (F4: +0.5)
- OEM transmission that does not match chassis manufacturer or chosen engine swap,
- Aftermarket sequential or dog box transmission,
- Aftermarket gear sets that do not match OEM ratios,
- Driven wheels may not be changed except for AWD to RWD conversion.
- The following driven wheels will be assessed the following points;
- All wheel drive (F1: +0.7)
- Rear wheel drive (F2: +0.6)
- Front wheel drive (F3: 0.0)
- All engine mods are free to get to the desired HP target.
- Supercharging, turbocharging or the removal of forced induction is allowed and the components are free.
- Methane and Nitrous systems are not permitted.
- Radiators and fans are free but must remain in the approximate OEM location. Radiator angle may be changed. Please replace coolant with water, as coolant is quite a bit more slippery on a racetrack if spilled, and more difficult to clean up.
- Intercoolers are free.
- Exhaust systems from the header back are free but must exit rearward of the wheelbase midpoint and not protrude more than 3” at the point where it exits the body work.
- Please be aware of decibel limits which may vary track to track.
- Fuel systems are free unless noted below;
- Fuel cells/tanks can be fitted into the vehicle provided that they are rigidly attached to body, with a metal bulkhead to separate the fuel cell/tank from the driver. Aftermarket fuel cells should be heavily reinforced when mounted, and not merely hanging off sheetmetal, etc.
- Batteries and electrical systems are free unless noted below;
- At least two brake lights are needed at all times.
- Weight reduction such as removal of OEM interior pieces, brackets and more, is free unless noted below;
- Any components bolted down within the interior must be properly attached to withstand substantial potential impacts.
- Ballast must be rigidly attached using Multiple, large hardware of grade 8+, ½” or larger, and installed with safety in mind.
- Driver seating location is free and can be swapped from LHD to RHD and vice versa.
Car Numbers and Banner
- All cars must display the car’s number on both sides as well as the front and rear of the vehicle.
- Depending on the event, Number boards for the side of the vehicles may be provided by the Gridlife team and if provided, must be used during competition. Numbers must be of adequate height with a 1.5” stroke and fit within the Gridlife Cup approved number board, if provided for specific event.
- Front and rear numbers must be at least 4” tall. It is recommended the front number in white color is placed on the upper corner of the windshield right below the banner opposite of the driver.
- Left over numbers and other class designations shall be removed or covered to prevent confusion.
- A Gridlife Cup Windshield Banner, if required for the event, is mandatory and will be provided by the Gridlife team.
- It is recommended to have the drivers last name on the front lower corner of the windshield opposite of the driver and on both sides of the quarter glass, white (or similar bright/readable color).
- All vehicles must be in good condition and appearance. Excessive damage must be repaired.
- The points system is designed to be open to a wide variety of vehicles with different types of speed while keeping competition equal and fair between all. The starting target ratio, which determines your competition weight at a chosen average whp, is 13.0 lbs/whp. While most mods in Gridlife Cup are free, the ones suspected to have the biggest impact on performance are assessed a points value. These points are added to the target ratio and can either raise or lower it. Cars with a ratio below 13.0 lbs/whp will be faster in a straight line with worse handling while cars with a ratio above 13.0 lbs/whp will handle better with less straight line speed. The goal is to keep the lap times of cars on both sides of the spectrum as equal as possible but please note this depends heavily on the track and not all combinations are guaranteed to be competitive.
- To determine final ratio, add the value of each mod selected together and add 13.
- The mods are split into 6 sections;
- Section A – Weight: Heavier cars can lower their ratio to help maintain brakes and tires. Make sure to select the correct range once all mods have been selected and weight has been calculated.
- A1: 2200-2499 -0.1
- A2: 2500-2799 -0.2
- A3: 2800-3099 -0.3
- A4: 3100-3299 -0.4
- A5: 3300-3499 -0.5
- A6: 3500-3699 -0.6
- A7: 3700-3799 -0.7
- A8: 3800-3899 -0.8
- A9: 3900 plus -0.9
- Section B – Tires: Competitors must select a tire compound from 3 different categories. Faster tires raise the ratio while slower tires lower the ratio. A tire size must also be chosen with the narrowest size lowering the most amount of points.
- B1: DOT Slicks 0.5
- B2: Semi Slicks 0.2
- B3: 200tw 0.0
- B4: 205 or Smaller -1.2
- B5: 215-225 -1
- B6: 235-245 -0.7
- B7: 250-275 -0.3
- Section C – Aero: Competitors can choose to run a splitter and multiple styles of rear aerodynamic devices. Adding downforce will raise your ratio.
- C1: No Splitter 0
- C2: Splitter 0.3
- C3 OEM Wing 0.0
- C4: Wing Stage 1 0.3
- C5: Wing Stage 2 0.4
- Section D – Brakes: Running no ABS lets you lower your ratio.
- D1: No ABS / disabled ABS -0.2
- Section E – Body & Chassis: Changes to you roofline raise your ratio while front MacPherson Struts lower your ratio.
- E1: Modified Roof Line 0.5
- E2: Front MacPherson Strut -0.2
- Section F – Drivetrain: RWD and AWD vehicles must raise the ratio as well as custom transmissions.
- F1: AWD 0.7
- F2: RWD 0.6
- F3: FWD 0
- F4: Sequential or Dog Box 0.5
- The ratio has a possible range from 11 lbs/whp to 15 lbs/whp but competitiveness, especially on both ends of the extremes are not guaranteed.
- It is possible to start at a chosen desired weight and determine the average whp as a result. Just divide your desired competition weight by your ratio to determine your average whp value.
- Please note some of the points assessed to certain mods may not be designed to be competitive but instead designed to prevent exclusion of cars with unique modifications or to have cheap alternative options available.
- The Gridlife Cup staff will continue to closely monitor all mods and their assessed points. The points system may be changed at any time if tweaking is needed. Please stay up to date.
- You may change your mods and points at any time during the year but you must submit an updated points sheet anytime you do so.
- Aftermarket ECU’s and hardware are allowed but will be closely monitored to prevent cheating the dyno readings.
- Any system where the driver or crew is able to change the tune/ECU MAP/boost levels during or after a session to cheat the dyno is strictly prohibited.
- Competitors found altering any system manually or automatically to change average whp during or after a session to blatantly cheat the dyno confirmation will be banned from Gridlife Cup, potentially indefinitely. There is a zero tolerance policy for cheaters.
- Competitors are subject to dyno confirmations after any session. Dyno checks will commonly be done on podium finishers, randomly chosen, or suspect vehicles that need to be verified. Dyno checking of power might not happen at every event. Data boxes may be used in some cases to determine acceleration rate and rough power of a vehicle.
- A dyno jet must be used on all rwd and fwd vehicles. Awd vehicles can use Mustang dynos but have to multiply their calculated average wheel HP by 1.1.
- Rwd and fwd competitors who have dyno results from other dynos need approval by staff. Their calculated average wheel HP may be raised as a result.
Average Wheel Horsepower
- To determine average horsepower, an electronic dyno plot file with HP data points in increments of 50 rpm is recommended. A dyno plot print out can be used but may not be accurate.
- It is possible to use peak horsepower instead if you are unable to calculate average horsepower.
- Average Wheel Horsepower Calculation
- Step 1: Determine peak horsepower and it’s RPM location as well as the redline
- = Peak wheel horsepower
- = RPM at
- = Maximum RPM at rev limiter
- Step 2: Determine how many additional data points are needed using the equation below.
- N = Number of Data Points. Round to the nearest whole number.
- Step 3: N determines how many additional data points for horsepower are needed. Start at and record the horsepower at each location at increments of 250 RPM in both directions. Do not go above . It is recommended to record more than N horsepower data points and then select the highest horsepower readings for the next calculation.
- = Additional horsepower data points
- Step 4: Using , the additional horsepower data points, and N, calculate your average wheel Horsepower.
- = Average wheel Horsepower. Round to the nearest whole number.
- Step 1
= 190 HP
= 8300 RPM
= 9000 RPM
- Step 2
- Step 3
- Step 4:
Lists of Changes and Edits
- 3/19/18 by Eric Kutil
- Section 5.a.
- Added no splitter section
- Section 5.c.
- Removed no aero and replaced with oem aero only.
- Section 19.b.
- Added wording on how to calculate final ratio
- Section 19.c.i.
- Added wording on point breaks for weight
- Section 19.c.iii.
- Updated oem aero classification
- Section 21.b. and 21.c.
- Added dyno types requirements.