Did a baseline dyno at Torque Freaks today.

[outofstep]

More power with 4.3:1 gearing would only be the result of lower frictional losses because the drivetrain would be spinning slower.

Re-read what I said. 4.3s will give you less power than the 3.X series.

The steeper the gear, the fewer splines it will have. The fewer splines, the more power is lost across the gap of the splines as the engery trasnfers from the one spline to the next across the ring & pinion gears in a centrifical manner. Power is needed to turn the gears, but the further the gap in splines, the power loss will be greater. Even though power is lost from the steeper gears, there are less splines to spin. This results in less time to rotate the ring and gear pinions. This is why you will accell faster even though you lost horsepower.

Now with a turbo car the power loss is even more pronounced. When the engine isn’t as loaded the turbo will spool up slower and to a lower maximum.

 

[Jeff Lange]

I was just thinking out loud, heh. I read what you said.

I don't think the difference would be as pronounced as you claim, but I haven't seen any dynos to prove either way.

I'd like to see an N/A guy dyno his car in 3rd and 4th and post the sheets.

 

[outofstep]

Dyno results on the 7M with gear changes were talked about on SF. DocJ posted the differences that he saw when he changed gears and that of someone else.

Check corral, ls1, ls6, corvette forums for dyno difference changes.

 

[toyota_supra_1988]

sweet, thats a pretty good baseline, i would turn up the boost and get it tuned, it should give you alot more pper