RULES - NATIONAL COMPETITION RULES - UNLIMITED CATEGORY
Unlimited Category is for production-based vehicles prepared beyond Sport, Tuner and Max which means any vehicle on DOT tires with less than 200 treadwear or on non-DOT tires. We do not expect these vehicles to be streetable. This is where you will find Time Attack monsters, Tube Frame GT cars and race cars that don't fit with the street-driven philosophies of the other categories.
As with Max, Unlimited Category vehicles may only be driven, stopped and steered through the wheels and tires. When the word “unrestricted” is used in these rules, it is under the assumption that the modifications and controls are within this parameter.
For National Events, Unlimited Category vehicles must be based on production automobiles and bear a noticeable resemblance to their production counterparts.
1. Kit cars and reproductions listed in Max Category are eligible for Unlimited Class.
2. There will be two classes in National Unlimited Category Competition—Unlimited 1 and Unlimited 2. Both classes must be production-based.
3. Full-scale tube-frame Grand Touring (GT), Production (P) and Prepared-Class cars are considered “production based.”
4. If Regions run under National Events Classing, and include a non-production class for Unlimited Category vehicles, it is recommended that Regions run the suggested classes for Formula Cars, Sports Racers and Specials.
Vehicles in Unlimited Category must meet Safety Level 2 or Safety Level 3 Standards, depending on tires.
A. Vehicles running on DOT-Approved tire will need to meet Safety Level 2 Standards.
B. Vehicles with non-DOT tires will need to meet Safety Level 3 Standards.
Unlimited Category - Authorized Modifications
Unlimited Category vehicles may do any modification listed in Sport, Tuner and Max Categories, plus allowances listed below.
Unlimited Category Classing
Unlimited is divided into two categories: Unlimited 1 (U1) and Unlimited 2 (U2). There is absolutely no guarantee of competitiveness for any vehicle in Unlimited Category, even though there will absolutely be a wide range of vehicle performance.
Cars which are production silhouette, but are over the displacement limits or under the weight limits for Unlimited 2. (U2)
1. U1 minimum weight: None
Cars which are production silhouette and meet the following criteria:
1. U2 minimum weight: 1 lb. per cubic centimeter of corrected displacement w/driver.
Example 1: a 1.6-liter naturally aspirated car would need to weigh 1,600 lbs. w/driver.
Example 2: A 1.6-liter single-turbo (1.5 x displacement for the turbo) would need to weigh 2,400 lbs.
Example 3: A 3-liter naturally aspirated car would need to weigh 3,000 lbs. w/driver.
2. U2 Maximum Displacement, 3.0 Liters corrected displacement.
- Rotary: Actual displacement X 2.0
- 2-Cycle Engines: Actual displacement X 2.0
- Forced induction: Actual or corrected displacement X 1.5
- For each additional forced induction unit 0.5 should be added to the forced induction displacement modifier (e.g., twin charged, twin turbo: Actual corrected displacement X 2. Quad turbo: Actual displacement X 3).
If Regions run under National Events Classing, and include a non-production class for Unlimited Category vehicles, it is recommended that Regions run the suggested classes for Formula Cars, Sports Racers and Specials.
1. Time Trial Special (TTS)
For any open wheel, sports racer or other vehicle which doesn’t fit into any other class. Cars must meet safety requirements for SCCA HillClimb or GCR.
2. Time Trial Atlantic (TTA):
SCCA Road Race legal Formula Atlantic cars, Formula B/1000 cars, P1 and P2.
3. Time Trial Winged (TTW):
Time Trial Winged. SCCA Legal Formula Continental/F2000, Star Formula Mazda, Formula Enterprise, Sports 2000.
4. Time Trial Non-Winged (TTN):
SCCA Legal Formula F, Formula 500, Solo Vee, SRF3.
5. Time Trial V (TTV): TTV:
SCCA Legal Formula Vee, Formula First, SRF.