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American Road Racing Series Rules

2020 Rules Version  1.0 (Click here to download a copy of the rules)

Drivers, owners and mechanics shall have no claim against or cause of action for damages, expenses or otherwise against ARRS Race Officials or Promoters by reason of disqualification or damage to either race car, driver or both.

We recommend that drivers build cars conservatively or speak with their local series directors.

1. Intent

The Intent of the American Road Racing Series, and the following rules, is to create a class that is inclusive of a variety of late model stock car chassis types, including but not limited to, late model, super late model, pro-truck, sportsman, modified, perimeter and offset type chassis that can compete in a series that encourages parity, low cost, racing skill, and sportsmanship.

We’re trying to make this a spec series for drivers, based on driving and having fun, with attempts to minimize differences in cars and emphasize driver skill. ARRS cars are fast and the most fun you’ll have on track for the money (we are also trying to be affordable). That said, all safety requirements must conform to the sanctioning bodies rules that ARRS is running with, please consult the appropriate CCR to ensure your car is safe.

2. General Overview

Competitors must assume that anything that is not explicitly stated in these rules is not allowed. 

3. Tolerances

There are no tolerances. The limits we have placed in this rule book already include a tolerance and are not to be exceeded. Build your cars conservatively so that there is no chance that you may exceed these limits.

4. Safety Overview

All safety requirements must conform to the sanctioning bodies rules that ARRS is running with. Please carefully read and adhere to their rules and CCRs or else you will not pass tech inspections!

– Any discrepancies or single weekend allowance are at the discretion of the governing sanctioning body

5. Chassis & Bodywork


  • Late model stock car – tubular chassis type cars allowed includes
    • ASA chassis
    • late model chassis
    • super late model chassis
    • sportsman chassis (stock front and/or rear clip)
    • perimeter or straight rail
    • modified chassis
    • 3 link and 4 link, no bird cage
    • metric chassis
    • pro-truck
    • super stock chassis (street car chassis or partial tubular chassis)
  • * Any circle track or road race chassis can be adapted to work in the series.

Frame & Frame Clearance

Minimum frame ride height is 4 inches, but, if a car excessively contacts the racing surface, the driver will be black flagged.


  • “Newer” car body styles are encouraged (5th gen Camaro, S197 Mustang, Challenger, CTS-V, etc).
  • Five star “ABC” style bodies are allowed.
  • Ducting may not enhance aero or downforce in any way.
  • A small, rectangle opening may be cut out of the very back center of the hood in order to allow fresh air to the carburetor.
  • Functioning brake lights (minimum of two) are required.
  • Exterior Side mirrors are allowed.


  • All cars must have a rear spoiler that is 6.5 inches tall, 60 inches wide and placed at an angle of 50 degrees mounted on the rear of the trunk lid.
  • No under body splitters, additional spoilers/wings/canards, or any device that increases downforce beyond what the “ABC” body style offers.
  • A small pan, directly underneath the engine is allowed as long as it’s purpose only serves to protect the engine and oil pan from track hazards.


  • No in-cockpit devices that allow the adjustment of suspension, engine power, chassis, aero, or any performance allowed (only exception is mechanical brake bias adjustment).
  • Passenger seats are encouraged.
  • No aero advantage may be gained through any interior modification.

6. Weight

All cars will have a post-race minimum weight of 2800 lbs with driver.

  • Cars that are under powered from baseline will be allowed to run 4 pounds lighter per average TQ under the limit.
  • Cars that are overpowered from baseline must add 16 lbs per average TQ over the limit.

* The logic behind this weight penalty/allowance is that the class baseline specs produce a car with 8 lbs/average TQ. If a car enters the series over that TQ number then they will be penalized with a weight addition double the optimal weight ratio for the class or, if they are underpowered, a weight reduction half of the optimal amount. This is to provide an incentive to produce cars as close to the baseline TQ and weight numbers as possible and eliminate the advantage of different setups for each track configuration. These adjustments are subject to change per year and with the addition of different types of chassis. Safe, LOW COST, Fun.

  • Weight is measured after timed competition sessions, this includes qualifying, qualifying races and main races.
  • Ballast must be added in block form and properly attached to the chassis, conforming to safety requirements per sanctioning body.
  • “Pellet” style ballasts are not allowed.

7. Engine

Engine power output levels are derived from a stock Chevy CT400 (604) or Ford 347 SR crate motor with approximately 400HP/TQ at the crank. 

Any naturally aspirated (no turbos, superchargers, nitrous, etc) engine configuration is allowed as long as it meets the specified torque requirements. If you have an engine with a power adder and would like it to be included in ARRS racing, contact your local series director for a possible waiver.

Baseline engine output is 350 TQ (+/-10) averaged at 3 different RPM points (3k, 4k and 5k)


  • at 3000 RPMs  TQ is 340
  • at 4000 RPMs  TQ is 360
  • at 5000 RPMs  TQ is 357

((TQ @ 3000) + (TQ @ 4000) + (TQ @ 5000)) / 3 ≤ 352. Legal, but a little high.


HP/TQ deviations from this baseline will result in a weight adjustment that is less optimal for performance.

All cars, regardless of motor type, will have an rpm limiter not to exceed 5400 RPMs. 

ARRS may require any car to be subject to dyno or data acquisition at any time in order to confirm compliance.

8. Transmission

A maximum of 4 forward gears and 1 reverse gear is allowed. 4th gear ratio will be 1.00

Transmissions must be manually shifted (no electronic or assisted gearbox mechanization).

9. Drive Shafts

No carbon fiber drive shafts, yolks or slip yolks allowed. Drive shaft must have a minimum of two 360 degree brackets placed around the drive shaft and fastened to the floor or cross member preventing the shaft from being dislodged and dropping onto the racing surface.

10. Fuel & Fuel System

Fuel pressure is open.
Fuel octane is open.
Fuel safety rules are deferred to the sanctioning body.

11. Suspension

Maximum track width is 80 inches for the front and rear wheels.
Maximum MSRP of shock absorbers must not exceed $250 per shock.
Only monotube shocks are allowed.

  • 101-110 inch wheelbase is required.
  • Traction control, stability control, launch control, and/or any electronic driving assistance is strictly prohibited.
  • Any solid rear axle is allowed, independent rear suspension is not.
  • All cars must be driven only by the rear wheels.
  • Sway bars are open as long as they are not cockpit adjustable.
  • Spring rates are open for front and rear.

12. Wheels & Tires

  • Wheels must be 15 inch diameter and steel
  • The spec tire is the Hoosier 3045 Asphalt Short Track 27.0 / 10.0-15
  • Any 8 inch wide tire is allowed.

13. Brakes

  • Brake calipers and pads are open.
  • ABS devices are prohibited.
  • Brake ducting is allowed.
  • Brake fluid recirculation is allowed.
  • Brake fluid coolers are open.

14. Protest

We recommend talking to the competitor about it first before telling everyone else that they are not compliant with the rules. After that please bring your concerns to the local series director.

  • Random tech inspections can and will occur on any/all cars at any event.

15. Sportsmanship & Conduct

This is our hobby… we do this for fun. It is each driver’s responsibility to promote fun, encourage ARRS class growth, and ensure that crew members, family, friends, pets and anyone who knows you conform to the highest standards.