Do You Need a Dyno Sheet for NASA TT?

Short answer: TTU, TTGT, and TTEV never; TT1–TT6 in practice yes, and the smart move is treating the dyno session as part of your build budget, not an annoyance. Here's the protocol and the strategy.

The protocol

Classing horsepower comes from a certified three-run dyno session — Dynojet mandatory for 2WD cars. The number that feeds your ratio isn't peak; it's the averaging method from the classing formula: engines revving past 7,000 rpm average peak plus seven points at ±250 rpm intervals; 6,000–7,000 rpm engines use five points; under-6,000 and all forced-induction cars use three. You may always declare straight peak or a higher number instead.

Multiple maps? Every map must be dyno'd and disclosed, the highest one classes the car, and any Dyno Mode must be declared. Power-switching during competition is banned outright.

Why "declare high" is the only sane strategy

Enforcement is real: officials can demand a dyno at any time, and GPS power monitoring operates at events. The rule that catches people is precise — dyno over your declared HP and it's a procedural violation even if your ratio still fits the class floor. First offense is a DQ, escalating from there.

So the game theory is one-directional. Declaring 10–15 hp above your sheet costs you a few hundredths of ratio; declaring optimistically low costs you event results and eventually a license. Heat, fuel, and a healthy engine on a good day all push power up, and your declared number has to survive the best dyno day your car will ever have. The GT3 RS worked example shows this headroom logic applied to a real declaration.

When you can skip it

No form, no dyno in TTU/TTGT (and TTEV runs its own near-stock EV ruleset). Also, as a practical matter, cars far from a class floor sometimes run on declared factory-spec numbers — the form uses your declared figures, and officials compare against them if and when they test you. But "far from the floor" is doing heavy lifting in that sentence: if your adjusted ratio sits within half a point of a boundary, get the certified sheet before someone gets it for you. Class boundaries and floors are in the class guide.

Budget reality: $75–150 for three pulls at most shops, once per configuration. Cheapest insurance in motorsport. Get the sheet, feed the real numbers into the TT Engineer tool, declare with headroom, and never think about it again — full onboarding in the complete guide.

FAQ

Which classes never need a dyno? TTU, TTGT, and TTEV — no classification form at all.

Can I use my tuner's dyno sheet? The rules specify a certified three-run session on a Dynojet for 2WD. A random single-pull tuner sheet isn't the certification format — and if the sheet shows more power than you declared, you've documented your own violation. Do it properly once.