When registering for an event, you can now use NARRA's new and improved Class Calculator to see which class of USTT or USGTC to run in. We highly recommend using the calculator BEFORE registering for USTT or USGTC events!
Check out the calculator below, and look for it on the left side of the page when you register for your next event! Gather the following info BEFORE using the calculator:
- The weight of your car. (Don't know the weight of your car? Google it here >>)
This should include the car weight in pounds (including all fluids except fuel).
- The driver's weight.
- The car's maximum rear wheel horsepower.
- If you do not know the wheel horsepower, you can calculate it using crank horsepower:
≈ crank horsepower - 15% = ≈ wheel horsepower (Use the mini Hp. Calculator on the right.)
- The tire width in mm.
Car Weight (lbs): 3000
Driver Weight (lbs): 160
Horsepower (Rear Wheel Hp): 500
Tire Width (Width in MM): 275
Your Class: GT-1 or TT-1
Register for an Event Here >>