Autocross Classes

Three or four performance levels (A, B, C and D) will exist for each model’s group.
Models are assigned to a specific level by definition.
Performance Level A is presumed the highest and C/D the lowest.
Three stages of preparation are herein defined.
Stage One preparation is permitted in the assigned base level.
Stage Two preparations elevate the car one level. (C>B or B>A)
Stage Three preparations elevate the car two levels. (C>A)

STAGES OF PREPARATION

STAGE ONE

• Any Appearance, comfort or convenience modifications that do not materially reduce weight without affect on handling or performance are allowed.
• Alternate seats, belts and steering wheels are allowed.
• Engine power chips and flash software are allowed.
• Any non-R-Compound, DOT-approved tire with discernable tread, safely fitting specified wheels for this class may be used. 140 UDQG or higher is considered non-R.
• Any wheel of stock diameter that does not require wheel spacers or body modifications, provided tire contact patch does not extend beyond fender opening when viewed from the top, perpendicular to the ground, is allowed.
• Any make and type of shock absorber using original type mounting hardware and attach-ment points is allowed.
• Substitution, addition or removal of sway bars using any bushing material, OE mounting points, and OE style end links is allowed. Tubular bars are allowed.
• Standard OEM springs may not be cut, shortened or collapsed.
• Suspension may be adjusted within OE design parameters without cutting or modification.
• Bushing type changes are not allowed.
• Any spark plugs, points, coils and/or ignition wire brand is allowed.
• Any make of exhaust system using OE header/ manifold without modification or removal of catalytic converter is allowed. Exhaust system must be operational.
• OEM active suspensions are permitted.
• Limited slip friction clutching ratio, rear drive ratio, transmission ratios, carburetion and fuel injection must be of standard OE type.
• Progressive 32/36 DGV 2-barrel type carbure-tors are considered as standard type.
• 38/38 DGAS or 40/40 DGAS are considered synchronous 2-barrels and are not allowed.
• All brake linings and pads are allowed.
• Non-stock brakes are allowed.
• Drilled rotors are allowed.
• Strut braces are permitted.
• Cone filter-type air intakes are allowed.
• Short-throw shifters are allowed.
• Non-stock transmission and engine mount bushings are allowed.
• No modification of the mounting points are allowed.

STAGE TWO

• Any non-software-programmable ignition system is allowed.
• R-Compound tires are allowed.
• Battery may be relocated, but not in passenger compartment.
• Ride height may be altered by change or modification of springs using original attachment points.
• Any type of suspension bushing material permitted.
• Offset bushings and adjustable camber plate may be used.
• Original mounting holes may be slotted.
• Bodywork may be modified for tire clearance.
• Tire contact patch may extend beyond bodywork.
• Tires must be DOT approved.
• Wheels may be any diameter, width or offset.
• Limited slip differentials may be added or slip clutch friction ratio increased above 41%.
• Locked/welded units are allowed.
• Roll cages are permitted.
• Exhaust headers are allowed.
• Gasket matching, but not porting, is permitted.
• Lightweight flywheels are allowed.

STAGE THREE

ANY OF THE FOLLOWING MODIFICATIONS ARE ALLOWED:

• Any non-stock camshaft change.
• Fuel injection modifications including inject-tors, flow meters, or control units such as Haltech, etc.
• Rear drive ratio may be changed to greater than 4.11:1.
• Carburetion changes greater than 2-barrel.
• Nitrous, Turbo, or Supercharger additions.
• Compression increased above 9.5:1 by change of pistons and/or shaving of cylinder heads.
• Porting or polishing of intakes or cylinder heads.
• Stroker engines or overbores beyond +1 mm.
• Suspension change requiring cutting or weld-ing of any component other than the spring itself, such as spring mounts, control arms, or cross members.
• User software programmable ignition systems and add on crank fire systems such as Electromotive.
• Removal of bumpers, interiors and seats.

RACE

THE FOLLOWING MODIFICATIONS WILL BE CLASSED AS RACE:

• Non-D.O.T. tires.
• Non-street legal vehicles.
• Stripped body shells.
• Non-stock chassis.