RUQWIKR

iTrader: (11)

Would like to take a quick "poll" of % driveline loss between engine dyno and chassis dyno results. If you never ran your motor on an engine dyno, then, no need to post up.

What I think would be interesting is % driveline loss instead of actual hp / tq numbers...list the % loss and the trans, converter, whether converter was locked, and which rear gear and tires.

A friend with a very similar combo saw a 22% driveline loss with a 4L60E, YTP4400 unlocked, 12-bolt with 4.11's, on 275/60/15 DR's (I use 325/50's for DR's which would have more loss due to extra weight). I have not had my motor dyno'd nor ran my current combo on the chassis dyno.

Just wanting the % drop vs. the raw numbers due to variation in correction factors, dyno types, dyno-to-dyno variation, etc. Not that other factors like engine temp, rear wheel / tire weights & pressures won't matter.

Plus, for those of you wanting to keep secrets, , then the % drop won't give the real number.

Thanks for the info. Take care. Dave

gator's 99TA

iTrader: (2)

ttt - i am interested in this, particularly in the A3 th400 setup

METALBEAST

iTrader: (1)

Big Mike ran his 408 LS1 on an engine dyno and it generated 592 HP. His Chassis dyno showed 504 RWHP thru a six speed tranny. That equates to 14.9% drivetrain loss.

BIGBOS

Thats about right on for a 6-speed, I think an unlocked TH400 with a big stall, through a 12-bolt dynoing on slicks could be upwards of 25%

427

iTrader: (3)

I ran a gen 1 sb with a blower at just a touch over 1300 at 7000rpm. The car has a Bruno 3 speed auto with a 7000 stall and a nine inch rear end. The rear wheel hp was 976.

Kurt

RUQWIKR

iTrader: (11)

Sounds about right...that'd be 25% with a loose converter and sticky tires. Another buddy with a 700 hp (flywheel) last 25% (A4, 5000 stall)...gained 3% back going from slicks to hard, real street 235's on the rear on the dyno...just to get a higher "number"...