dsz28

If I dynoed 358 to the wheels what would the hp at the crank be?
Thanks

conan

iTrader: (5)

You can acount for about a 12% (+ -) power loss from the drive train.

dsz28

I dont know what this means .

Mike02Z

iTrader: (13)

About 401 at the crank given a 12% loss in the drive train.

seawolf18

iTrader: (18)

I thought drive line loss was about 13-15% for manual and 18-20% for auto?

RGV_Z28

iTrader: (7)

Not sure about actual numbers, but a4's do lose more hp than m6's because there is more stress on their drivetrain.

777

iTrader: (21)

I'd say you make around 420hp at the crank. Given a 20% loss through the auto and decent sized converter.

S8ER95Z

iTrader: (3)

I thought the generally accepted numbers were 15% manual and 18% auto?

BlueSix

Assuming a 20% loss (guessing the dyno was with the converter unlocked) you are making close to 450 bhp.

BrandonDrecksage

iTrader: (1)

why does it matter? you could pull the engine and dyno it on a engine dyno.

'Trust'

iTrader: (24)

OR, he could just guesstimate, pulling an mildy modded engine just to see what it'll make on an engine dyno = stupid.

staringback05

iTrader: (8)

ive seen some guys with about 20-25hp loss...im pretty sure the driveshaft grabs like 5-10 by itself

BlueSix

Drivetrain loss isn't a static number.

dedge

I have been using the 15% rule on the A4, but I was also told that changing the gears from 2:73 to 3:73 thick gears would eat up the HP too! And that the torque fiqures are wrong because that purple stall TC gets hungry. Is there any reason that someplaces lock the TC during the dyno and some don't?I know that the dyno is just another tuning tool and the real world is what counts but I was wondering why.

staringback05

iTrader: (8)

i understand that, thats why i gave a small range...im just saying what ive seen on a dyno before, so its not a figure for everyone

BiggCmass

iTrader: (1)

358 * 1.15 (15% loss) = 411.7
358 * 1.20 (20% loss) = 429.6

not exact science and I realize that the numbers are somewhat skewed based on percentages, but I'd say a healthy median is 420 HP

BrandonDrecksage

iTrader: (1)

trying to figure out what your making at the crank when you already know what you make at the wheels is stupid.

BlueSix

Your math is wrong. You divide the wheel horsepower by what percent of the brake horsepower you thinkg the whp is.

i.e.
358/.85 for a manual (15% drivetrain loss)
358/.80 for an unlocked auto (20% drivetrain loss)

FL01SS

I never knew that! I'd been doing it the other way forever.