rw hp vs flywheel hp

[zguy00]

ok, i have always wondered this. i know the hp at the wheels will be less then at the fly wheel. how much is lost? the dyno said i had 295 at wheels, what does that put it at the flywheel?

[95 Camaro Z28]

is no exact calculation. Raw power dyno'ed from the flywheel is the best way to find out. Typically a 295 rwhp should be, 315-320 fwhp. But there are alot of factors. Once the power moves to the trans its all dependant on wear and tear or freshness of the parts it is running through. Older parts that slip are not very efficent.

[VetteC5RFrEak]

Originally Posted by 95 Camaro Z28

is no exact calculation. Raw power dyno'ed from the flywheel is the best way to find out. Typically a 295 rwhp should be, 315-320 fwhp. But there are alot of factors. Once the power moves to the trans its all dependant on wear and tear or freshness of the parts it is running through. Older parts that slip are not very efficent.

It's actually referred to as 315-320bhp (brake horse power I believe is the terminology). Otherwise if you use FWHP...it is like saying Front-wheel horsepower.

[toofazt]

Usually you loose about 10-15% on a M6 and 15-20% on a A4.

[Wild Willy]

Yeah, there is drag and heat in the fluids- every time you change directions, like in the driveshaft/axle turn, you loose a couple percent.

Varies, depending on fluid viscosity, temp, bearing clearance- manuals are generally more efficient, less loss- figure aproximately 10-15% in a manual, maybe 15-20% in an auto- better if the auto has a lock-up torque converter, too. These are just general figures, but will get you in the ballpark-

[zguy00]

ok, thanks guys. slp was pretty close. they say increase about 20hp.

[CRASH00527]

Originally Posted by toofazt

Usually you loose about 10-15% on a M6 and 15-20% on a A4.

its really no more than 15% max on almost all cars. that the avg.

[CRASH00527]

FWHP is the hp rating that ALL car manufacters use to test and sell their vehicles. that the engines max peak hp. (ie:Camaro SS 330) b/c the engine is out of the vehicle in a lab on dynometer. the industry avg. is about 15% less than advertised

the RWHP is the power put out on your actual RW's hitting the pavement. all the power your engine is putting out going thru to the RW's. (ie: Camaro SS 270-290ish)

your losing all that power from engine to RW's . you have to bridge the gap. thats what mods are for. ie catbacks, headers, CAI etc.. you have to relieve the pressure to achieve max claimed hp. than you can make more hp with more mods..ie cams engine work, tq converters.

picture holding garden hose at full blast (FWHP) than twisting it to stop or slow down flow.(losing flow to RW's) now release. (mods added to release) more power

[Silver35thZ]

nicely said crash, i like the analogy at the end

[95 Camaro Z28]

Originally Posted by CRASH00527

picture holding garden hose at full blast (FWHP) than twisting it to stop or slow down flow.(losing flow to RW's) now release. (mods added to release) more power

Not quite.

Modifications to the motor release motor restrictions, increase flows, increase fuel, sometimes bore and stroke of the motor and allow the motor to create more power at the flywheel, but there is still a loss of power through the drivetrain.

there is really no way to run a motor through a transmission and have it free of drag (meaning free of hp loss).

Adding mods can make the motor more powerful, but it does not in anyway affect how much horespower is lost through the drive train.

THINGS YOU CAN DO. like lighter flywheels, better trans components, transmission cooler, lighter balanced drive shaft and fresh rear end WILL affect the power transition through the drive train. and increase the efficiency of the components.

[CRASH00527]

Originally Posted by 95 Camaro Z28

Not quite.

Modifications to the motor release motor restrictions, increase flows, increase fuel, sometimes bore and stroke of the motor and allow the motor to create more power at the flywheel, but there is still a loss of power through the drivetrain.

there is really no way to run a motor through a transmission and have it free of drag (meaning free of hp loss).

Adding mods can make the motor more powerful, but it does not in anyway affect how much horespower is lost through the drive train.

THINGS YOU CAN DO. like lighter flywheels, better trans components, transmission cooler, lighter balanced drive shaft and fresh rear end WILL affect the power transition through the drive train. and increase the efficiency of the components.

maybe i didnt clarify it enough like you did in addition to my explantion. but this is coming from slp and a few other guys ive spoken to.

if im wrong please correct me

[00SSvert]

His explanation did correct you (or like you said, add to and correct).

If you have 300 hp at the flywheel and lose 10% through the drive train, you'll have 270 hp at the rear wheels. If you increase the engine's efficiency, through modifications (such as exhaust, intake, cam, supercharger) you're still loosing 10% through your drive train. After modifications at the flywheel you're now making 400 hp, you'll put 360 hp to the rear wheels.

From the above 300 hp at the flywheel scenario, if you only modify the drive train without touching the engine and reduce the drag to 5% instead of 10%, you'll increase the rear wheel hp to 285 hp, and on the 400 flywheel example you'll increase the rear wheel hp to 380 hp.

[CRASH00527]

kool. no prob.

what else can we do to increase hp w/out touchi g engine. what was he talking about changing the flywheel? or driveshaft?

[VetteC5RFrEak]

Originally Posted by CRASH00527

kool. no prob.

what else can we do to increase hp w/out touchi g engine. what was he talking about changing the flywheel? or driveshaft?

Lightening the flywheel and driveshaft allow the motor to spool up quicker right? As well as allowing the motor's RPM's to drop a lot quicker? It's also less rotational mass that the motor has to compensate for.

[CRASH00527]

thats what i thought. how much would something like that cost? never really though about doing anything like that. but now i will lol