"ah atleast someone can do math"
He is not here, but I'm sure he can do the math.
I would rather not repost an actual mathematical formula from Jim C. on how to calculate loss from a Dyno without his permission.
But there it is:
[quote]"Typically the driveline loss from crank to rear wheels is around 15-20%, most BMW's are close to 20%, Porsche 911's and Honda's are around 15%. So if you make 345 at the crank you should see around 276-289 hp at the rearwheels. The type of dyno will also affect the numbers as Clayton and Dyno Jet use different methods to measure the HP. ALSO note that the PERCENT LOSS is **NOT** the same as the FACTOR used to equate RW HP w/ shaft HP!!
Example:
Loss = 17%
RW = Shaft * ( 1 - 0.17)
RW = Shaft * 0.83
RW * 1.20 = Shaft
The factor is always 1/(1-(loss%/100))
For the math impaired.. here's a table of values
Percent Factor
Loss To Use
12 1.14
13 1.15
14 1.16
15 1.18
16 1.19
17 1.20
18 1.22
19 1.23
20 1.25
Enjoy,
Jim .
[quote]
Sorry I was dividing by .75 instead of multiplying by 1.25. So its 316hp.
Didnt know it was a race engine, all I caught was the 253rwhp and 2.5l.
But here is the actual multipliers to use from now on when people are spitting out the "actual" flywheel #'s translated from thier RWHP #'s.
