Originally Posted by
AndyJ
If the SRT differential were installed in a Limited 6 speed, by how much would the RPMs go down at 70 mph? Any idea how to calculate this?
Yes, simple math, just divide 3.07 by 3.27 and multiply that by whatever RPM you see now.
Say at 60 you have 2200 (just a close guess/example) 2200*.94=2068 or if you like dividing 2200 / 1.065 (rounding...) 2065
You don't need to do any tire size, gear ratio calculations, you only want to know the difference, basically %6½ less RPM, simple as that.
Or if you want to see the difference at the max, at 150MPH it will be somewhere about 350 RPM less from 5500 down to about 5150, but then, maybe you won't have enough torque to the wheels to get to 150...