could someone with 4.10 rear axle ratio and the m6 trans. please let me know what the engine rpm is at 80 mph. i have the 3.23 rear axle ratio right now,i run about 1800 rpm at 80 mph. i'm considering going to the 4.10 ratio soon. thanks alot!!!!!!!!!!!!!

 

www.f-body.org/gears/

Edit: Sure you don't have 3.42's?

 

I think mine is a little over 2 grand, like 2200 or so but I never really go 80, unless I am racing...

 

recently swapped from a4 over to m6, thats why i have the 3.23 ratio. thanks

 

Reason I asked was because on a '97 M6 1800 RPM is 80 MPH in 6th. My car came with 2.73's, but put 3.42's in it a few years ago. Sometimes the door codes don't match what's in the car.

 

Depends on the tire diameter. With a 3.23 rear, stock tire diameter (25.65" with the Z-rated tire option) you would be at 1,700rpm in 6th gear. You might want to check your tach vs. the PCM RPM reading, since the tach typically reads 100-200RPM higher than actual. The PCM will give you the true RPM.

When you go to other gear ratios:

3.42 - 1,800
3.73 - 1,965
4.10 - 2,160