Anyone.. know

 

approx 342

 

Depends on what flywheel you have, pullies, etc...

 

i would say about 313 to 322 !

 

auto or manual?
Most 287HP flywheel Z's dyno 220-240 stock.
Figure 330-365 using similar driveline percentage losses.

 

There is roughly a 15% difference between flywheel HP and rear wheel HP.

There is less that 15% loss on FWD and more than 15% loss on AWD.

 

I don't think a 40-50rwhp gain would equate to a 26-37 flywheel hp gain

I'd guess in the 340-350hp range

 

About 340 crank!

 

There is no guessing required ppl. There is a 15% difference between flywheel and rwhp.

280hp X 15% = 322rwhp

 

How does a Sti (awd) 280 whp dyno 350 at flywheel?

 

shouldnt you subract the 15 % from the crankshaft HP figure to get the RWHP number?

In that case its


330 Crank HP - 15 % Drivetrain loss = 280.5 RWHP

 

Actually, for most 350Z's, the drivetrain loss is 6.3-7.3%, assuming that, 315-335 would be your number at the flywheel.

 

i always thought it was about 17% drive train loss for manual Z.. :-/

 

Assuming the stock crank is 280-287hp. Most Z's (manual) are 236-244rwhp, that's around 6-7% drivetrain loss.

 

this is wrong math

you're doing it backwards

for example, 322 x .85 does not equal 280
it's 273.7

you'd actually need to multiply 280 by 1.1764 (or 100/85)

that'd give you 329.4 crank hp

it's all contigent on what the base dyno whp was at..

maybe someone has 280whp, but their base dyno was 270 - so that wouldn't be much of an improvment.

Without knowing the base dyno, we can only guess what crank hp it'd be

 

You divide crank hp by Y (any number you want to use as the drivetrain loss), then take number, remember it, do the crank hp minus the number you got when you divided crank hp by Y, and there's the WHP, it's a trial and error to see what drivetrain number is closest to the WHP number.

Here it is:
A= Crank HP
B= Drivetrain loss %
C= Wheel horsepower
D= Drivetrain loss in hp

A divided by B = D
A minus D = C

 

I hope no one cheats off your math test:

287 HP to crank - stock figures
240 HP to th wheels - give or take stock figures

240/287 = 83.6% which equates to 16.4% drivetrain loss

Using this figure to find what 280rwhp equates to:

280/X = 83.6% - Where X = our crank HP number
So:

280 = .836X
280/.836 = X
or
X= 334.9 BHP

EDIT:
334.9 BHP assumes a stock Z with 287BHP will produce 240 HP at the wheels.

simple algebra - not "trial and error" -

 

Trial and error for me. Never was good at algebra.

How do you get 16.4% from 83.6%?

 

100 - 83.6 = 16.4

 

A 6% loss would mean that a 287hp Z would lose only about 17 hp by the time it got to the rollers. And a stock z does not dyno at 270. A manual rear wheel drive car usually loses around 15-18% to the wheels.