Dynamometer Results & Comparisons - Has anyone ever nailed down driveline loss?

I was wondering if anyone has gotten a hold of what kind of driveline loss percentage different combos. cause. I ask as I am going with a t56 and 9 inch and was wondering if anyone has done an engine dyno to chassis dyno comparison of that, or anything else that one can empirically figure it from?

Thanks in advance.

I lost 100 hp from flywheel to rear wheel. That was with the ls7 clutch which is a lot lighter then the one in the car now

is that based off of the horsepower in your sig? or what was that dyno number? Thanks.

There is no 'nailing it down', as it will change from chassis to chassis, tranny to tranny, rear end to rear end, wheel to wheel, converter to converter, etc.

You could pick up rwhp going from a 12 bolt to a 10 bolt, from 20" rims to 17's, and from a glide to a t56 without touching the engine...

ok, maybe "nailed down" isnt the right term, but a little narrower than 12-25%

http://ls1tech.com/forums/general-lsx-automobile-discussion/1449182-drivetrain-loss-percentage-set-amount.html

The motor made 650 on an engine dyno with a carb only running up to 6000 rpm. It then made the number in the sig through a 90/90 and 85mm maf. As I said the clutch was a ls7, 3" steel driveshaft and the 9" with a 370 gear. No tricks with the motor, Evans water pump and an ATI dampner with 10% reduction

Awesome thanks for the responses. It at least will put me on track for realistic expectations at the dyno.

I don't know about other dynos but the dynojet 224x has a negative horsepower run option where it measures how long the drum takes to decelerate with the clutch pushed in or the trans in neutral. That would tell you exactly how much power a particular setup looses. my $.02

Just installed a Moser 9" lost 10hp at the wheels.

FWIW - which isn't much: 656 on the engine dyno. Number in sig on DJ.

I don't know about other dynos but the dynojet 224x has a negative horsepower run option where it measures how long the drum takes to decelerate with the clutch pushed in or the trans in neutral. That would tell you a little bit about how much power a particular setup looses. my $.02

Fixed it for ya!

705hp and 599 rwhp through a locked auto in a C5,

15.0% loss last I checked.

thank you for the input.

FWIW - which isn't much: 656 on the engine dyno. Number in sig on DJ.

Pretty close at the flywheel with WKMCD having a higher RW with I would guess a slightly lighter drive train.

Variations such as this, makes a good argument for calculating fuel system requirements based on FWHP....

Around maybe 18-19% for me at 800rwhp. T56-12bolt. I'd imagine less than 15% at 500rwhp. The harder and faster you accelerate, the more resistance.