How much does the set gear impact the dyno result?

Lada-1 · 03-29-2026, 04:04 AM

How much does gearing affect dyno numbers?

Im used to using the PerfectPower(https://www.perfectpower.pro) connected to the Racebox Mini for the road power measurements. I accelerate from 2000rpm to the injection cut. This shows the delta of ca 7% between the gear 5° vs 4°. This seems a bit high to me.

Additional info which might help (All numbers recalced at the crank power):
Im stage 2 (custom tuned BM3, OE cats, Midpipe 3.5", Eventuri intakes). If measured on 5th gear the Perfectpower numbers match the dyno numbers. Lower number for 99OCt pump fuel; higher mixed to (17-20%) Ethanol content (also shown on the PerfectPower graph).

The second PerfectPower graph shows pull on gear 4° (20% Ethanol).

RACE M3 · 04-11-2026, 10:17 AM

Everything affects it. The goal is to see a before and after doing things the exact same way.

Even doing it in the summer and winter will net you difference results on the same dyne, same gear and same way.

If you want to see how your car stacks up get a draggy. 60-130mph or 100-200khm will give you the best idea if the cars performing as it should. I don't like the idea of the high speed all the time so I measure my car in 3rd gear from exactly 2000rpms and bang the rev limiter. My cars 30-35% faster than stock with that test depending on the weather.

03-29-2026, 04:04 AM	#1
Lada-1 Private First Class 41 Rep 134 Posts Drives: G80 CS ; F31 340iX Join Date: Sep 2022 Location: CZ iTrader: (0)	How much does the set gear impact the dyno result? How much does gearing affect dyno numbers? Im used to using the PerfectPower(https://www.perfectpower.pro) connected to the Racebox Mini for the road power measurements. I accelerate from 2000rpm to the injection cut. This shows the delta of ca 7% between the gear 5° vs 4°. This seems a bit high to me. Additional info which might help (All numbers recalced at the crank power): Im stage 2 (custom tuned BM3, OE cats, Midpipe 3.5", Eventuri intakes). If measured on 5th gear the Perfectpower numbers match the dyno numbers. Lower number for 99OCt pump fuel; higher mixed to (17-20%) Ethanol content (also shown on the PerfectPower graph). The second PerfectPower graph shows pull on gear 4° (20% Ethanol). Attached Images Last edited by Lada-1; 03-29-2026 at 04:12 AM..
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04-11-2026, 10:17 AM	#2
RACE M3 Captain 901 Rep 772 Posts Drives: 02 S2k, 04 Rx8, 22 M3P, 23 m3 Join Date: Sep 2022 Location: USA iTrader: (0)	Everything affects it. The goal is to see a before and after doing things the exact same way. Even doing it in the summer and winter will net you difference results on the same dyne, same gear and same way. If you want to see how your car stacks up get a draggy. 60-130mph or 100-200khm will give you the best idea if the cars performing as it should. I don't like the idea of the high speed all the time so I measure my car in 3rd gear from exactly 2000rpms and bang the rev limiter. My cars 30-35% faster than stock with that test depending on the weather.
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