Class Calculator 3.0

Welcome to the NEGT class calculator.


Use this form to see your adjusted NEGT power-to-weight ratio, which class your car falls into currently, your minimum competition weight for that class and to enter your class declaration.

To compare multiple configurations, we suggest using our spreadsheet calculator tool linked on the "Rules and Forms" page.

Contact NEGT for classing if intake restricted, supercharged or you are running a ported rotary. Cars detuned electronically will be classed using their full OEM rated power, torque and all relevant modifiers.

Please reach out to us with any issues or questions.

-NEGT Staff
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Driver / Owner

Time Attack and Sprint entries can enter their last name.

General Car Info

[-0.25%] per year before 2000, [+0.25%] per year after 2000
Top rated variant of the long block, regardless of year of manufacture or model in which it was delivered
Top rated variant of the long block, regardless of year of manufacture or model in which it was delivered
As raced, with driver, any ballast and post race fuel. An approx number is okay, we will have scales available at the event to get you a more exact number if needed.

Engine

(If different than car)
Turbocharged?
Supercharged and sequential turbo applications contact the series for classing.
Added Dry Sump Oiling System?
Changes to Head, Cam, Engine Size or Compression Ratio?

Chassis & Drivetrain

Tires

Not every tire is called out by name. If you don't see your tire, choose the category where you see similar tires and make sure to inform us what tire you are running in the comments section below.

Average advertised tire width: +1% per 10mm more than and -1% per 10mm less than 245mm. (-2.5% negative modifier limit)

Brakes

Largest individual caliper piston count

Suspension

Select the highest level on car.
Moved suspension mounting point(s), non-OEM knuckle geometry (includes bolt-on / weld-on parts), any number of spherical / solid bushings (not in a “paid” for part), non-OEM style sway bar, more than one non-OEM or modified link/arm per any corner (toe adjustment/correction free). Per pair if applicable, up to 7. Purpose built racecars take max adder.

Aero

Select highest level that applies. See below to select individual items if you only have one item or wing from a higher category.
Individual Aero Items
Select if equipped. This is to allow use of an item from a higher aero category without taking the whole next adder. Each category is described in the Aero Level dropdown and more info is available in our rulebook.
Any of the following added or changed: splitter fences, side skirts (more than an inch below lowest floor or structure), ducting for hood vent, relocate radiator, radiator is leaned more than 10 degrees from vertical, swan neck wing mounts, wing end plates over 72 in² or other added or effective small aero items (per item or pair/set of matching items)
Body
Select all that apply.

Conclusion

This calculator will produce nine different classes: GT2, GT3, GT4, GT5, GT7, GT9, GT11, GT14, and GT18, plus GTU for data gathering purposes. GT5 and under are subject to change for competition. The # in each class name represents the class cutoff ratio for that class. For example, the cutoff or most powerful ratio for GT14 is 14:1. The lower the number, the higher the overall performance level of the car.
I'm interested in:
Select all that apply.
Please provide any feedback as well as include any relevant info such as current series you run in, what class your car is in, peak dyno numbers if you have them and anything unique about your car, including if running an inlet restrictor and related details. Did you have trouble or were you unsure about anything? Thank you!