WHP and HP - the difference?

[Dunrick]

Why do people post hp, when I'm getting the idea that WHP is the only thing that matters....If somebody could explain this for me...just basically tell me if whp is all that matters...thanks! Peace

[02blksi]

crank horsepower differs from WHP (wheel horsepower) due to the fact its the actual power at the crank, before it is affected by drive train loss.

WHP- is the measurement of just that horsepower @ the wheels, most commonly used to measure actual power your car has "street value"......


HTH- Joe:)

[Dunrick]

so basically whp is everything.....our car only has 138whp...is that other 22 hp just totally lost to drivetrain?

[02blksi]

kinda sorta not really...... sometimes car manifacturers "inflate" their crank horsepower numbers, best example off hand was the new nissan spc-v's originally when they came out they were advertised with like 180 crank horsepower, after testing most were only making low 140 whp on the dyno 40 or so horspower loss, this resulted in nissan "revising" their numbers. Dont forget crank horspower does not take into consideration such things as the accesories that are also powered by the engine, alternator, water pump, ac compressor, etc everything right down to the weight of the crank pulley affects the total output to the wheels of our cars, so that 22 horspower loss is pretty efficient considering all factors. HTH- Joe :)

[Dunrick]

Lets say I was to go dyno tommorow, would my car test say 134 whp just because its not made as well? I'm wondering if they vary a lot...can some have more? Thanks for all the info man, peace

[ssvr6]

You can take 10 brand new Si's off the dealer lot, dyno them all and get 10 different numbers. It's that simple.

All cars and engines are different.

Steve

[Dunrick]

How common is it to have different hp #'s? Also do they very widely? Like say by 5 hp at times? Thanks

[ssvr6]

Yes, in some cases.


Steve