Calculating kw at wheels to kw at the crank

[justinfox]

Hi guys. Here's one for the mathematical/technical peeps out there.

I just dyno tested my little Alfa Romeo for the fun of it. She's reading 78.8kw at the front wheels. Hahah, so small in comparison to your cars (thus I am still hunting for a Skyline!).

But how do I calculate 78.8kw at the wheels to how much power I have at the engine/crank?

Any help appreciated.

Here's a pick of her on the day:

[JimX]

Usual drivetrain loss for a front wheel drive car of around that power is usually around 15-20%. So at a guess I would say it's got around 90-100kw at the crank? It looks fairly new, you could probably even go off the factory spec for a pretty close estimate.

[benm]

Yum ! Nice car

[SLY33]

yeah, alfa should be able to give you the engine power.. its prob even listed in the buyers index of mags such as wheels or other.

[Guest Robo's]

As a rough guide, i translate the kw to hp at the wheels, 78.8*1.34= 106rwhp, then that roughly translates too 106 kw.

[rb25]

a good guide for rwd gts skylines is the the NUMBER of kw @ the flywheel is the same number but in hp @ the wheels. Example:

187kw @ flywheel = 187hp @ wheels (140kw) or

300kw @ flywheel = 300hp @ wheels (225kw)

and so on and so forth.......

Pretty much what Robo's said.....

-rb25