Stupid question: what the difference with WHP and HP?

[hawaiiannights]

I know WHP is wheel horse power but I don't really understand what is the WHP compared to HP? Could someone explain.

When cars manufacturers state our cars have 130HP what are they reffering to? And is there a simple formula to translate WHP to HP?

Thanks in advance....

 

[tonkabui]

there's no real "formula" for translating the difference between crank horsepower and wheel horsepower. we suffer from a lot of drivetrain loss, and being automatic, we lose even more. the reason i say there's no easy formula is because the corolla, which also has a claimed 130 crank horsepower, dynos at over 120whp. we, on the other hand, are lucky to break 103. generally, it is agreed upon that fwd cars lose about 25% power through drivetrain loss, but that doesn't hold true for some cars.

so in the end, our ultimate goal is to see the #'s dramatically increase in whp. it's what really counts.

 

[hawaiiannights]

I see....

 

[seakrait]

usually manufacturer's advertise with crank horsepower (basically, what the engine is making)..... but the power that really matters to us is wheel horsepower (the power at the wheels)....

losses are mostly due to frictional losses, esp. with our slushbox (literally a slush box because of the atf - automatic transmission fluid).... regular trannys with clutches lose less hp.....

in this month's edition of SCC, Dave Coleman talks about HP/WHP and drivetrain losses...... apparently around 17% is average. he makes more sense than i do. go read it.

thus, when you see 130hp, expect less because 130 sounds better in ads then 103.

 

[70]

25% is high for a front driver. 18-20% loss is in the average zone. Or 17% if you like SCC.

25% is closer to the all-wheel drive cars.

 

[DooMer_MP3]

Maybe he meant 25% for front wheel auto? But yeah, if the MP3 is indeed 140hp, we typically dyno at about 109. So thats about 21-22% driveline loss.

Chris