What is RallyCross?
RallyCross is the most widespread and readily accessible form of extreme dirt motorsport in the Sports Car Club of America, and the perfect place to see if you have what it takes to power slide your way to victory. Imagine a scaled down version of a rally stage laid out on a non-paved plot of land where the course is delineated by traffic cones instead of trees or rocks.
The entry fees and equipment requirements are considerably less than those necessary to enter any other forms of performance rally, so in most locations one need only arrive at event registration with a safe hardtop vehicle and the entry fee. Our SCCA Region has helmets to loan and will assist the first-time competitor with entering the appropriate class, making their way through technical inspection and finding their way around the course. Best of all, it’s great fun!
The stock category of SCCA RallyCross is the most restrictive and made up of three classes: Stock Rear Wheel Drive (SR), Stock Front Wheel Drive (SF) and Stock All Wheel Drive (SA). Cars must run on DOT-approved tires which are not marked “For competition only”, “Not for street use” or similar. There are a few minor modifications allowed, most for RallyCross-specific protection/safety, non-performance cosmetic accessories or minor performance enhancements like cat-back exhaust or drop-in air filter.
Like Stock, the Prepared Category is made up of three classes: Prepared Rear Wheel Drive (PR), Prepared Front Wheel Drive (PF) and Prepared All Wheel Drive (PA). Cars in prepared class may do anything allowed in stock, and some additional modifications. Additional mods including allowing any tires (other than home-built studded tires) exhaust modifications, any shocks/struts and more.
In keeping with the category structure in Stock and Prepared, Modified also has three classes: Modified Rear Wheel Drive (MR), Modified Front Wheel Drive (MF) and Modified All Wheel Drive (MA). These classes see the most modifications including major weight reduction, aftermarket forced induction, and aero-devices like wings or splitters.
(text from https://www.scca.com/pages/what-is-rallycross)