Thread: Had the 3.9 RRC dyno'd today

Originally Posted by GuyG

Would there be much difference in figures between a rear wheel dyno with centre diff in and a 4wd dyno

with a Rear Wheel Dyno there is less power sapping thru your Transmission as Power transfers thru your Clutch , Gear Box , Rear Differential then to Rear Wheels

4WD Dyno the same power transfers thru Gear-Box , Transfer Case and both F/R differential ,then to the wheels hence there is more horse-power being sapped thru the transmission line.

so if your engine is 120kw at the Flywheel on a 2wd it might translate to 100kw at the rear wheels when Dynoed , but on a 4wd Dyno same engine power at the Flywheel might translate to 80 kw of power at the wheels.

+++

Edit : I just re-read your Question and I don't have any real figures
I know mine being 83kw at flywheel was dynoed at 49.8 kw at wheels

and this translated to app 40% power loss thru transmission.

Originally Posted by GuyG

So how do you convert hp to kw, then with the torque from ft/pd to what ever the current measure is?

Cheers

100hp = 74.6kw.
100ft-lbs = 135.6Nm.

Originally Posted by Disco_owner

Edit : I just re-read your Question and I don't have any real figures
I know mine being 83kw at flywheel was dynoed at 49.8 kw at wheels

and this translated to app 40% power loss thru transmission.

Must be RPM dependent too.
My turbo Isuzu powered one puts 74kw to the ground at 2000rpm. But if that lost 40% then it'd be producing 123kw.

It'd be great if it was.

ok so my car was done in third Sweet. It is interesting to see the differences in all these motors.

So are you guys getting your cars dyno'd at all 4 wheels, or rears only. Or is it not possible to do RWD. Just asking, because for some reason my car didn't want to be dyno'd on a 2WD dyno.

Mine was done with the rear wheels only, but I have a LT230 fitted, my understanding is that if you have the viscous coupling fitted then it should not be done on a rear wheel only machine.

The mechanic lifts the front diff and puts it on axle stands.

I unfortunatelly don't have a print out atm, will get one next time its tuned and see what he says about a 4 wheel dyno - just out of comparison interest to other here

well like Philips mine was done at greames on a 4 wheel dyno.
I hope to be doing another dyno run up this way (qld) after sorting out the thor injection.