Compare a wheel-power result with an assumed drivetrain-loss conversion and an empirical trap-speed model. The output highlights assumptions instead of declaring a dyno accurate or inaccurate.
A dyno result depends on the machine, setup, correction standard, gear, tires, temperatures, and test procedure. This page exposes two rough models so you can see whether they tell a similar story; it does not authenticate a sheet.
The trap equation is an empirical model, not a measurement of crank power. Aerodynamic drag, weather, slope, timing location, race weight, vehicle setup, and the equation's calibration all influence the comparison. Use the displayed percentage as a prompt to review the underlying data.
Drivetrain loss is not one fixed percentage by drivetrain layout. The presets are explicit assumptions, and changing one directly changes the crank estimate. A measured engine-dyno value and a controlled chassis-dyno value are needed to quantify loss for a particular condition.
Specific output can help compare engine combinations, but displacement alone says nothing about boost, airflow, fuel, speed, durability, or test conditions. The calculator reports the number without assigning a universal “healthy” or “built” category.
Peak power is one point. Complete torque and power curves show output across the tested engine-speed range, but acceleration also depends on gearing, mass, traction, shifts, and road load. Compare full curves from controlled tests and focus on the operating range relevant to the vehicle.
Dyno software applies smoothing to turn noisy raw samples into a clean line. A little is normal; a lot hides problems. Heavy smoothing erases the small dips and wiggles that reveal a flat spot, a boost-control hiccup, or a fueling glitch - it can also round a jagged peak up into a higher, prettier number. If a curve looks like it was drawn with a ruler, the smoothing is turned up. Ask for a lower smoothing setting, or for the raw overlay, when a sheet looks too perfect to be real.
For 450 whp, a selected 15% loss assumption produces about 529 crank hp. A 3,700 lb entry at 119 mph returns about 487 crank hp from the trap model, so the assumption-based figure is roughly 9% higher. That difference is the useful output; it does not identify which estimate is correct.
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.
No single conversion proves accuracy. Compare the estimates, then review race weight, weather, slope, correction standard, dyno setup, and pass data.
There is no fixed loss percentage by layout. Loss changes with components, speed, temperature, tires, test method, and load; the presets are assumptions only.
Dynamometers can use different hardware, load strategies, loss models, correction standards, and setup procedures. For modification comparisons, controlled back-to-back tests with documented settings are more useful than unrelated headline numbers.
Ask for the original run file or complete report, correction standard, weather data, gear, tire information, smoothing, and a controlled baseline. A screenshot alone usually cannot establish authenticity.
Peak power is one point; the full curves show output across the tested range. Compare complete curves under controlled conditions and relate them to gearing and the vehicle's relevant operating range.
It provides a second empirical estimate from entered race weight and trap speed. It does not prove engine power because drag, weather, slope, timing location, setup, and model calibration affect the result.
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