Rwhp
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
crank horsepower x 0.88 for manual and 0.82 for auto trans = rwhp
RWHP/0.88 or 0.82 = crank horsepower
These are your mathamatic formulas to convert crank horsepower and Rear Wheel horsepower.. 0.88 represents a 12% drivetrain loss for manual transmission cars and 0.82 represents an 18% drivetrain loss for automatic transmission cars. Assuming the white FRC is your car and you have the stock 6 speed it came with.
440rwhp divided by 0.88 = 500 motor or crank hp.
or
500 crank horsepower times 0.88 = 440 rwhp
Using these formulas on a stock 2000-2004 Ls1
350 crank horsepower times 0.88 = 308 rwhp (manual tranny)
308 rwhp horsepower divided by 0.88 = 350 crank hp (Manual tranny)
350 crank horsepower times 0.82 = 287 rwhp (auto tranny)
287 rwhp divided by 0.82 = 350 crank horsepower (auto tranny)
RWHP/0.88 or 0.82 = crank horsepower
These are your mathamatic formulas to convert crank horsepower and Rear Wheel horsepower.. 0.88 represents a 12% drivetrain loss for manual transmission cars and 0.82 represents an 18% drivetrain loss for automatic transmission cars. Assuming the white FRC is your car and you have the stock 6 speed it came with.
440rwhp divided by 0.88 = 500 motor or crank hp.
or
500 crank horsepower times 0.88 = 440 rwhp
Using these formulas on a stock 2000-2004 Ls1
350 crank horsepower times 0.88 = 308 rwhp (manual tranny)
308 rwhp horsepower divided by 0.88 = 350 crank hp (Manual tranny)
350 crank horsepower times 0.82 = 287 rwhp (auto tranny)
287 rwhp divided by 0.82 = 350 crank horsepower (auto tranny)
Last edited by David426; Sep 11, 2011 at 02:29 PM.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
You're welcome.
I use: RWHP/.97 x 1.15 = FHP It's a bit more accurate and more realistic. Btw, the "15" (15%) in the 1.15 is not cast in stone but still represents a good, conservative number to use for "sticks". Some guys say 12%, some say 13%, etc.
Safety Car
Joined: May 2007
Posts: 4,812
Likes: 46
From: Taylorsville North Carolina
If you are making badges to put on car, you car round to whatever looks/sounds good. When I was sc'd at 527 rwhp, I had some Z06 badges made that said "620hp" - nice rounded number. I am na at 513 now but still have the badges. Close enough.
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Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
I have always used this for my manual 6 speed:
RWHP/0.85 = Flywheel HP
0.85 assumes 15% driveline loss for manual
Example..... My 448RWHP/0.85 = 527 Flywheel HP.
Toque
RWHP/0.85 = Flywheel HP
0.85 assumes 15% driveline loss for manual
Example..... My 448RWHP/0.85 = 527 Flywheel HP.
Toque