Quote:
Originally Posted by Alext
Sorry - I don't think the 1M has 390HP from factory unless I am missing something?
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It all depends what correction factors you use to estimate crank power. Many 1Ms are dynoing around 320-330 hp at the wheels, up to around 370 torque on a dynojet. With these numbers I'd estimate the stronger 1Ms are putting out around 370 crank hp under optimum conditions, up to 420 torque (so up to 110% of factory ratings).
I understand that during BMW's standard power test they heat-soak the motor, which reduces power and may partly explain why the factory numbers are conservative.
The E9X M3's V8, on the other hand, seems to be slightly over-rated by the same measure, generally dynoing at 350 hp at the wheels (so more like 95% of factory ratings). It's likely that in BMW's test they don't drop off as much due to heat-soak, however...