Hey, just wondering. How much power do you think my 88 IROC loses from the flywheel to the rear wheels. Like 20%? Thanks!

-Tom

 

It depends on the setup but yea, 20 - 25%

I have heard 20% for a stick and 25% for an automatic.

 

I hear more along the lines of 15% for T-5/T56, and 18-20% on 4 speed autos.

 

20% for a stick and independant rear suspension. That's a typical Corvette figure. I think for us it's more along the lines of 10-15% for a stick on a solid rear axle.

 

I was informed by the operator of a Dynojet Dyno that the following are the drivetrain losses.
700R4 Auto 22% is average or 20/25% range.
5 SP Man. 16% " or 15/18% range.

 

the 700R4 sucks up around 18%, T5 and T56 usually take up in the 15-16% range

 

U R
What is the SOURCE OF YOUR NUMBERS??? Or are you
guessestimating??

 

I guess I don't know for sure but I have always heard 15% for manuals and 20% for auto. as well.
But I was wondering does it matter which manual or which auto.?
Like is it different for a 700R4 and a Ford AOD???

 

Hey Z28DJP1987. Can you ask that guy about 'vettes or IRS drivetrain loss, just for my own curiosity. I'm just wondering what he might say (even if it's still thirdhand knowledge). Thx.

 

Jza
I will not have a chance to talk to him soon. However; my opinion
is that percent of drivetrain losses on a vette will not vary that much. They may be on the low side of the averages but thats it.
A IRS rear or Ratio's do not affect the physic's on the Dyno, its the rear wheels on the rollers.

 

Hey

How much % lossage will u lose if u put a transgo shiftkit on the A4 Automatic transmission. Im thinking that it would go down by 5% or so, what do u think. Thanks

 

iroc
Your guess would be as good as mine. But you are using only
2nd & 3rd on a Dyno Pull and I don't think the shift kit will make a diffences, My opinion.

 

5% of 20% or to 15%.

A good chunk of power loss is through the torque converter. A shift improver will not "fix" that loss.

 

I believe the extra loss from the Vettes is due to the CV shafts since it is independant.

 

Right. On an IRS, the torque has to go through 4 more universal joints than a solid rear axle. I'm not saying that would make a huge difference, that's just the reason I wanted you to ask that guy what he's seen dynoing 'vettes (if he has).

 

on ls1s the difference between the 6 spd and the 4l60e is about 35 rwhp.