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Vehicle & Tire Allowance List

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Vehicles with a better than 13:1 Weight to HP ratio, but are still allowed in the Sport Class and are ruled as 13:1 or worse in the Tuner Class:

• Focus ST

• Cobalt SS

• WRX (2014 & Older non STI)

• Dodge Caliber / Neon SRT4

• Mini Cooper JCW (2001 - 2006)

• Chrysler 300C / Charger R/T

• Mazdaspeed 3

• V6 Ford Taurus (All)

• All vehicles with a solid rear axle. (Excluding any limited production High performance models ex Mustang GT500 )

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Tires rated at under 100TW, but are allowed

• Zestino Circuits 

• Toyo Proxes RR

• Pirelli Trofeo R

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Vehicle Requirements​

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• SUVs, Trucks, Vans and other high centre of gravity vehicles are not allowed for safety reasons. (Lowered Street trucks are allowed)

• Vehicles track width must be greater than its height VIEW HERE

• Performance brake pads and brake fluid are highly recommended!

• Have a structure and bodywork that surrounds and protects the driver at least to his waist level when seated in his normal driving position.

• Exhaust noise level less than 94dbA from 100 feet away

• All loose items must be removed from the vehicle

• Must have no fluid leaks that will drop oil or antifreeze on the track! 

• 3 Point seat belt at minimum (Exception for Karts)

• Kart requirements VIEW HERE *Karts are only allowed at StratoCross Competitions​

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Defintions​

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• Treadwear - The UTQG rating that is stamped on the tire from the factory. 

• Tire Width - The manufacturer's rated width of the tire.

• Bolt On Part - A part that bolts up to the original factory mounting points.

• Drop In Turbo - A commercially available turbo that is designed to fit directly into the stock turbo location without modification.

• O.E - Original equipment parts, or options, that your vehicle came with from the factory. 

• Solid Rear Axle - Both rear drive wheels are connected together by a solid beam 

• N.A Engine - Naturally aspirated engine

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Full Classing Rules: 

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Sport Class

For vehicles with a 13:1 weight to horsepower ratio or worse and vehicles on the allowance list. Calculation is the factory listed curb weight in pounds of the vehicle divided by the factory listed horsepower of the engine in the car.

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Engine:

The engine must be an O.E available engine for that model and remain stock, as from factory, with the exception to:

• Air filter & intake upgrades up to the turbo inlet or throttle body/carburetor inlet. Whichever comes first.  

• Exhaust upgrades from the first flange off the header on naturally aspirated cars and the first flange off the down pipe on turbo cars. 

• Engine tunes 

• Common reliability mods or fixes that don't increase the horsepower of the engine are allowed. e.g. oil cooler & baffles, catch cans, upgraded radiators, motor mounts etc.

• New! Vehicles with a 18:1 or worse weight to hp ratio are allowed external bolt-on upgrades. Turbo & supercharger must remain O.E  

 

Drivetrain:

Drivetrain must remain stock as from the factory with the exception to:

• Gearing ratios may be changed in the differentials only

• Limited slips may be added

• Upgraded shift linkages & parts may be used

 

Suspension & Brakes:

• Any part that can be bolted or fitted into the factory mounting locations, without modification, may be used

 

Interior & Exterior:​

• New! Interior - must have a dash, door cards & passenger seat at minimum unless a roll cage is installed, then interior can be fully removed.

• New! Exterior - minor cosmetic changes are allowed, performance enhancing aero upgrades beyond factory options are not permitted.

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Wheels & Tires:

• Any wheel may be used

• Tires must have a rating of 100TW or higher

• Tire width is limited to a maximum of 225 or +10mm over the widest O.E available size for that model's generation, including the optional factory installed packages and higher trim levels. **This excludes any trim version or added package that upgrades the model to a better than 13:1 ratio. (e.g. Widest O.E size is 235 = Max allowable width is 245)

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Slow Tire Extra Modification Allowances View Slow Tire List

If you use one of the tires on the Slow tire list, these additional modifications are permitted: 

• New! No tire width restriction

• External engine bolt-on upgrades excluding adding forced induction.

• Full interior removal & aero upgrades allowed

• "Drop in" turbo upgrades are allowed if the vehicle has a 18:1 Weight to HP ratio or worse, otherwise turbos & superchargers must remain O.E​​​​​

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Tuner Class

For vehicles with a 9.5:1 weight to horsepower ratio or worse, or with modifications not allowed in the sport class. Calculation is the factory listed curb weight in pounds of the vehicle divided by the factory listed horsepower of the engine in the car.

 

Engine:

Modification allowances are based on the weight to horsepower ratio of the vehicle using the factory listed curb weight of the vehicle divided by the factory rated horsepower of the engine that is currently in the car. Allowance list vehicles are considered 13:1 or worse.  

• For engines with swapped blocks & heads, use the horsepower rating from whichever engine had the higher rating. E.G. K20A2 (200hp) head on a K20A3 (155 hp) - use the 200hp horsepower rating of the K20A2    

 

12.99:1 or better

Vehicles must use the O.E equipped engine or a swapped one of the same manufacturer with the following restrictions:

 

Turbo & Supercharged Cars

The engine must remain stock, as from factory, with the exception to:

• Air filter & intake upgrades up to the turbo inlet or throttle body/carburetor inlet. Whichever comes first. 

• Exhaust upgrades up to the first flange off the down pipe 

• Engine tune 

• Common reliability mods or fixes that don't increase the horsepower of the engine are allowed. e.g. oil cooler & baffles, catch cans, upgraded radiators, motor mounts etc.

 

Naturally Aspirated Cars

The engine must remain stock, as from factory, with the exception to:

• Any externally bolted on part may be replaced & upgraded

• Minor internal reliability mods that don't increase engine performance are allowed. e.g. Oil baffles & pumps, better head gasket etc.

• Engine tune

• Turbocharging & supercharging is not allowed 

 

13:1 or worse

Any engine (stock or swapped) and modification is allowed with the exception to:

• Turbo must be the stock one for that engine or a commercially available turbo that is designed to bolt directly into the stock location. Also known as a "drop in" turbo 

• Naturally aspirated engines can't be turbocharged or supercharged

 

Drivetrain:

• No restrictions

 

Suspension & Brakes:

• Any part that can be bolted or fitted into the factory mounting locations can be used

 

Interior & Exterior

• No restrictions

 

Wheels & Tires:

• Any wheel may be used

• Tires must have a rating of 100TW or higher

• New! Tire width is limited to a maximum of 255 or +10 mm over the widest O.E available size for that model's generation, including the optional factory installed packages and higher trim levels. **This excludes any trim version or added package that upgrades the model to a better than 9.5 :1 ratio. (e.g. Widest O.E size is 265 = Max allowable width is 275)

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New! Slow Tire Extra Modification Allowances View Slow Tire List

If you use one of the tires on the Slow tire list, these additional modifications are permitted: 

• No tire width restriction

• Intercooler & downpipe can be upgraded on 12.99 :1 or better cars

• Any 2000 & older vehicle can use a "Drop In" upgraded replacement turbo

• Forced Induction can be added to any naturally aspirated vehicle with a 13:1 ratio or worse if using an O.E available engine for that model.

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Performance Class

For vehicles with a 9.4:1 weight to horsepower ratio or better, or with modifications not allowed in the other classes. Calculation is the factory listed curb weight in pounds of the vehicle divided by the factory listed horsepower of the engine in the car.

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Engine:

• No restrictions 

 

Drivetrain: 

• No restrictions 

 

Suspension & Brakes:

• Any part that can be bolted or fitted into the factory mounting locations can be used 

 

Interior & Exterior

• No restrictions 

 

Wheels & Tires:

• Any wheel can be used

• Tires must have a rating of 100TW or higher 

• Under 200hp vehicles & all naturally aspirated 4 cylinder cars are allowed to use under 100TW rated tires ​

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Open Class

For Karts, open wheel race cars and anything non production or street car based 

• Must be a commercially available vehicle that is made for racetrack use or one built to a sanctioning body rule set.

• New! Only for vehicles that do not fit into the other classes 

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