Rolling Road Results + Power @ Flywheel & wheels query

[loggyboy]

Had my nova on the Rolling Road at Janspeed in Salisbury this morning. The results were very impressive and a little suprising considering the state of tune of my engine (or lack of)
http://www.loggyboy.com/images/MeritMk2/DynoScan1.jpg
Now these figures are at the wheel, so how do i get to the flywheel figure and how accurately?

[Stanley]

Looks good.

Whats the spec?

[loggyboy]

Standard Dispak redtop, decat, custom system based on magnex, K&N filter! oh and 160k on the clock!

[R1CH]

You sure the powers at the wheels ??
They should of been able to give you the figure at the flywheel, most rolling roads usually calculate transmission losses in to the run, usually between 15 & 20%. You cant just add 15 / 20% tho, i've got a few print outs of a run i did one shows power @ dyno, one shows it with 15% losses and one with 20% losses, and if you add 15 / 20% to the power @ dyno run the figures are no where near !!
Sure someone (Stu ?) might know a way of getting a rough figure ?

Rich

[Adam]

Usually about 15% losses.
I agree those figures look a bit high for at the wheels.

143x1.13=164.45bhp
Torque-157.66

Probably slightly over-read imo, a de-catted xe will probably do 150-155bhp, but the mileage is getting on a bit,Lol.

[Philsutton]

well to be honest working out the flywheel figure from wheel bhp is kind of guess. When I did the rolling road I used a figure of 15% loss, but the guy who builds the rollers says that 30% is closer to what it should be. I always go off the wheel bhp as that cant be made up or altered much.

[scott.parker]

Well my engine when it was RR'd with engine rebuild and 2" system (the one i have forsale) and a ITG filter and Power cap ran 165bhp 158lbft

This shows the loss etc.

http://img232.imageshack.us/img232/916/scanalldataeditwh6.jpg

Scott

[loggyboy]

Usually about 15% losses.
I agree those figures look a bit high for at the wheels.
Probably slightly over-read imo, a de-catted xe will probably do 150-155bhp, but the mileage is getting on a bit,Lol.

TBH the other figures that were taken on the day were fairly realistic so im inclinded to believe they are quite close.

This would also explain why my car has been keeping up or beating cars it shouldnt. 170 at wheels would give it nearly 230/tonne. :D

[kevster]

sweet figures .