Dyno Sheet Interpreter

Reading a Dyno Sheet Like a Skeptic

A dyno is a comparison tool, not an absolute one. Different dynos (Dynojet, Mustang, hub dynos), different correction standards, and different operator choices can move the same car 10% or more. These checks catch the common games:

The Trap Speed Cross-Check

Trap speed cannot be faked by dyno calibration. If the dyno-implied crank power and the trap-speed-implied power agree within ~7%, believe the sheet. If the dyno reads far higher, suspect an optimistic calibration or STD correction being quoted as SAE (run the numbers through the Dyno Correction Calculator - STD reads ~4% higher by itself).

Drivetrain Loss Games

The two classic moves: quoting a huge loss percentage to inflate the crank estimate ("450 whp is really 600 at the crank!"), or quoting wheel figures from a happy dyno. Typical real-world losses: RWD 12-18%, AWD 15-20%, FWD 10-15%. Outside those ranges, ask questions.

HP per Liter as a Smell Test

• 60-90 hp/L (crank) - typical naturally aspirated street engine
• 90-130 hp/L - high-strung NA (S2000, GT3) or mild boost
• 130-200 hp/L - healthy turbo car territory
• 200+ hp/L - serious built-motor boost; if the sheet claims this on stock internals, scrutinize it

Same Dyno, Same Day

The only comparison that settles anything is back-to-back pulls on the same dyno in the same session. Everything else - including this page - is sanity checking, not gospel.