[p912guy]

So this thread has been successfully hijacked with a discussion of crank HP vs wheel HP. Any update on the OP's efforts to possibly take over this lease?

[M235]

Originally Posted by Viffermike

This is waaaaay oversimplified. It's not all good engineering; it's also partially a function of the drivetrain used. For instance: a 911 has less driveline power loss because a RWD rear-engine car doesn't need mechanisms that sap crank power -- driveshafts, extra differentials, etc. -- that a front-engine RWD car requires. It also doesn't need a transfer case because the engine is mounted longitudinally (crankshaft alignment: front to back) instead of transversally (crankshaft: left to right), as is the case with many FWD cars.

Bryan_f22's 15-percent figure is a good one to use for engines mounted on the opposite end of the drive wheels. It can be lower for cars such as RWD 911s or mid-engined cars, or higher for AWD cars. It all depends on the hardware in the way between the crankshaft and the driven rubber because it all robs some power.

But back to the issue: All that's important is to understand where any power figures you come across or need are taken from, then translate them as needed. No one's going to laugh at you ... and if they do, they're not worth your time. Who has time for mod snobs?

Your Right! excuse the over simplification . using porsche was probably not the best example since the engine is right at the back which decreases fly wheel power loss

figures are based on the environment the engine is operating on, many variable need to be taken into consideration...

- coolant/oil temps, air pressure
- air pressure/temp/humidity
- engine temp it self
- fuel type used

all the above can effect engine performance, Im sure i missed out more variables.

Then theres the marketing perspective of things, why say 265hp when you can say 320hp.

[M235]

Originally Posted by p912guy

So this thread has been successfully hijacked with a discussion of crank HP vs wheel HP. Any update on the OP's efforts to possibly take over this lease?

.... respectfully hijacked