Originally Posted by Eyeman
That's outstanding!. I'd say the comparison results prove that that dyno reads good to a little low. For the M3's, 340 on the dyno calculates out to very close to 400 at the flywheel. Mercedes probably pushes the C63 number a little just to get close to that magical 500hp number.
So really the number that is way off is the 1M. Basically BMW stock tuned the 1M to what should pretty much be called 400hp and 450ft/lbs!! What makes that especially nice is it should help y'all resist the temptation to add a tune since that's pretty much the numbers you'd get with those mods from a tune!
What makes the "tune" argument valid in this sense is the fact that two of the three M3's had a tune and both performed at this dyno on this day with less HP (by 2 HP) than the stock M3 which was +2 HP over my mark. This does not make sense to me on how you can tune an engine in the aftermarket and have near stock levels.