M3 engine HP overrated vs dyno vs drivetrain losses

[pbonsalb]

Originally Posted by Sal@Evolve

We test as many 335's on our dyno as M3's. That's alot of cars tested.

The quoted different in HP of the two different cars is 108HP.

What do we actually see? Around 100-110hp difference on average.

That's the important fact for us.

I am aware that in the US, 335i's make nearly the same power at the wheels as the manufacturer suggests should be at the flywheel.
However......... we don't see this and quite frankly none of the european tuners see this.

Something is up with the testing of 335's in the US.

Even still, it still doesn't matter. The dyno is used to show a difference.

Maybe the the US tuning is different. Euro M3 get 420 and US get 414.

Maybe our gas is not as good. A lot of US gas has 10% ethanol and some premium US gas is only 91 octane by our standard (I know our 93 octane is supposed to be pretty close to Euro 98 octane).

[Dave07997S]

Originally Posted by pbonsalb

Maybe the the US tuning is different. Euro M3 get 420 and US get 414.

Maybe our gas is not as good. A lot of US gas has 10% ethanol and some premium US gas is only 91 octane by our standard (I know our 93 octane is supposed to be pretty close to Euro 98 octane).

No its DIN vs. SAE..same output.

[tscdennab]

The 335i gets about 273whp on a Dynojet, while the M3 gets about 340whp. About 70whp difference. Or 80 crank hp difference. It does seem overrated to me. The crank difference should be 110hp.

BUT at 8200RPM where the M3 has the most power, the drivetrain losses should be significantly higher than a 335i at 5800RPM where it has the most power. Maybe at 8200RPM the losses are much higher than 15% like you are counting on a 6500-7000RPM car. However, this is not a reason for joy because the wheel power is all that matters. And the M3 wheel power is low because maybe the drivetrain losses are high at high RPMs. A strong case for a turbo M3

[J08M3]

I say it's the dyno that is overrated