NEWBIE Q#2: hp

[project trueno]

ok this one is more simple...what does bhp stand for...? sometimes u guys say hp and bhp, are they same, or are they not?

also what initials stand for hp AT THE WHEELS? (or is there none?)

thanks :o

more questions to come

[toymaniac]

whp= wheel horse power
chp= crank horse power
bhp???

[project trueno]

ya doesn't it piss you off? what the hell is BHP?

[Lafora]

bhp = brake horsepower

brake horsepower is the actual or useful horsepower of an engine, usually determined from the force exerted on a friction brake or dynamometer connected to the drive shaft.

should i elaborate further on what that means?

[project trueno]

ok got it :wink:

so you would refer to a dyno'd hp figure BHP right?

[Lafora]

from a guy's site who's from the UK

Three different horsepower values are used in talking about engine performance: (1) Indicated horsepower is the theoretical efficiency of a reciprocating engine, which is determined from the pressure developed by the cylinders of the engine; (2) Brake or shaft horsepower is more commonly used to indicate the practical ability of the engine, or the maximum performance, which is the indicated horsepower minus the power lost through heat, friction, and compression; (3) Rated horsepower is the power that an engine or motor can produce efficiently for sustained periods of time.

*******
and no, bhp != hp from a dyno. Brake horsepower is a common term and refers to the power measured at the crankshaft using a "prony" brake. A prony brake was a simple lever that was connected to the crankshaft with a brake. As the brake is applied, the lever would deflect and power was indicated.

in case you are still confused, lemme reiterate. Brake horsepower is a calculation where the engine horsepower is measured at the point of output with no load from a chassis or any accessories and with fuel and ignition operations under ideal conditions. Brake horsepower is often called gross horsepower today.

i just don't want you to confuse bhp with dynoed hp which usually means whp

[project trueno]

so WHP is the hp rating WITH load from the chassis and pretty much everything the power needs to go through all to way to the wheels right?

where or when does one use BHP?? :-? shouldn't the figure be far off the WHP figure since it bears no load? (besides the heat and friction as mentioned above)

[Lafora]

whp = hp at the wheels

where or when they use it is up to the manufacturer. as far as i know, thye've stopped using that figure for quite somet ime.

and yes it would not be the same as whp cuz they aint' the same thing!

[fatredcircle]

if bhp is ever used, its just a marketing termonology.

manufacturers, 90% of the time, messure th hp from the crank. Then, when it would go to press or to print, they just rate it as BHP...pretty insignificant and innacurate for the layman's sake.

two popular ways to measure hp is at the crank and at the wheels.

the crank hp is app. 30% more than what is measured at the wheels because of the loss in the drivetrain.

100 hp at the wheels = 130hp at the crank.

Nick

[Consynx]

i think they still use BHP when talking about Concept cars...
or cars to come(some now out)

i.e. before the 350Z was released, they were giving horsepower figures w/ bhp.

[PeaZs]

Originally Posted by Consynx

i think they still use BHP when talking about Concept cars...
or cars to come(some now out)

i.e. before the 350Z was released, they were giving horsepower figures w/ bhp.

yea, new cars nowadays on ads, i see them say bhp