what are some of you guys running for rear end gears? for acceleration? thanks.

 

Autos on average 3.73s, manuals 4.10s.

 

ok that was easy. and how can i tell what in my car now? it does have true posi. but thats all i know.

 

Look in the glove box and see if you have the code GU5. That's the only one I know and is for 3.23 gears from the factory.

 

The m6 97 model comes stock with a 3.42 ratio.

 

oh thanks
so is gearing a good thing to do to get fast quarter mile times?

 

Search the Drivetrain Section, its been discussed a few times...

 

All V8 models left the factory with a limited slip differential ("posi"). Why would your car not have one?

Going to a higher numerical rear axle ratio increases the torque available at the rear wheels. 3.73's will increase torque by 9% over your 3.42 gears. 4.10's will increase the torque at the rear wheels by 20%. Obviously, the car is going to accelerate faster from a stop, IF you have decent enough tires to maintain traction. But, you are going to hit redline on the engine at lower MPH in each gear. So how much you "gain" is going to depend on how far you are running (1/8th mile, 1/4 mile), and how much HP you are making. You want to cross the line at the 1/4 mile near your redline in 4th gear (1:1). You choose you rear axle ratio and tire diameter to accomplish that.

But... in very general terms, a street car is going to feel/be a lot quicker with the higher numerical gears, particularly for the "stop light drags". But traction will become more of a problem.

You may see a slight loss of fuel economy as the rear axle ratio goes higher, but the double O/D gear ratios of the M6 generally limited the impact of gas lileage loss.

And..... moving to the "Drivetrain" forum.