bdford

So does anyone know around how much tq and hp is lost through the resistance in the drive train of a 6-speed f-body on stock 3.42 gears?

CBIII

iTrader: (6)

um. Ill be corrected if im wrong, but whp is wheel horsepower and bhp is brake horsepower, so your drivetrain/gears make no difference since the only variable being changed is rotational mass of the wheel.

HTX

iTrader: (1)

there is HP loss in the drivetrain. For example all LS1's dyno in the ball park of 350 hp at the flywheel. But depending on the drivertrain of the transmission, gears, tires, power to the rear wheels will be significantly lower.

I i remeber corectly the M6 usually has a RWHP # that is approx 10% lower than FWHP.

Im not sure what BHP is measured at, but i know that FWHP and RWHP are big differences.

AU N EGL

On a Corvette, not sure about F-body:

Manual is about a 15% loss

Automatic is about 18% loss

So for a 350 BHP rated ( Brake HP or at the Fly wheel )

Manual is ~ 297 RWHP ( Rear Wheel Hp)

Automatic is ~287 RWHP

These are good estimates, but do very.

JDP

iTrader: (21)

i dont get why its a percentage. use 15% for instance

if a car makes 500 at the flywheel, it will make 425whp, so it loses 75hp through the drivetrain

say now it makes 1000 at the the flywheel, with a 15% loss it will only make 850whp, it loses 150hp, so why does it take more power to turn the same drivetrain.

i think the percentage system is bullshit

CBIII

iTrader: (6)

he ias asking about difference betwen rwhp and bhp, not rwhp and fwhp.. driveline doesnt affect the difference between rwhp and bhp....

bdford

bhp is at the flywheel, that is what I meant. It is a common misconception that bhp is measured on the hub w/o the wheel but it is actually the correct term for the more common term fwhp. sorry for the misunderstanding.

bdford

this sounds like a valid argument. why would it take more power to turn the same drivetrain with a more powerful engine (the 15% rule)?

Sammyboy

iTrader: (9)

Just use the 15% rule and you'll be fine....

ndfrsd6

iTrader: (5)

if you look at bhp and flywheel there usually close if not the same ....but i agree with JDP the percentage system seem to go away when your putting the bigger numbers down...

ndfrsd6

iTrader: (5)

but i guess really who cares about flywheel hp its whats getting to the ground that matters imo...

JDP

iTrader: (21)

thats saying that my car takes 75hp to turn my 6speed and 10 bolt, then if i spray a 300 shot its going to take 120hp to turn the same drivetrain.

dont worry about drivetrain loss, a 6 speed car is going to dyno higher than a th400 car, those are just numbers, track numbers are what count

ndfrsd6

iTrader: (5)

at first i was worried about my loss by converting to the th400 but like you said its track #'s that count

AU N EGL

I agree. YES the percentage does very depending on all the drive line components, but the 15% is GOOD ESTIMATE.

The only real way to know is to do run the engine on an engine dyno. Install the engine in YOUR car and do a rear wheel dyno.