PoonerElRay

According to the Dyno report posted on the forums, the max HP is 167.9 and max torque is 178.5lbs.

Why is that different from what MB posts 192 HP and 200 lbs torque?

dasMafia

looks like the car experiences about 12-13% driveline loss, which is EXCELLENT.

I'd be damn happy with that, that is about what we get in teh Z3s, and we are the best of the BMWs, so I would be VERY happy with those figures.

Buellwinkle

Factory numbers are average numbers done on an engine dyno and represent HP/Torque at the crankshaft with all accessories (altenator, water pump, A/C, flywheel etc..) and stock intake and exhuast. To do an engine dyno would be very expensive and require removing the engine, intake, exhaust and setting it up on the dyno so you are unlikely to see this sort of testing from anyone except a manufacturer or race team. When a tuner gives you HP/Torque numbers, they are estimating what it may give you on an engine dyno using chassis dyno numbers. Of course some have been known to exagerate these numbers for marketing reasons in the same way many CEO's use clever math to "cook the books".

The dyno's you'll see on this forum are done on a chassis dyno and represent how much HP/Torque is developed at the rear wheels (RWHP). It takes energy to rotate the wheels, differential, driveshaft, transmission and that explains the difference. You can minimize the difference by getting lighter weight components like light weight wheels and driveshaft but it will never be zero. Some say that 15% is an average driveline loss for a manual trans car and closer to 20% for an automatic. The only way to tell for sure is to remove the engine and put it on an engine dyno and I've never heard of any anyone doing that on a regular (non-race) car but it's possible.