Gearing Change Calculations

[honestabe]

I'm going to be changing from a 3.73 diff to a 4.10 diff. By my calculations that's just a hare under 10% higher. Is my theory of losing 10% off my topend and gaining 10% on acceleration, and 10% higher RPM's while driving at the same speed in the same gear correct? I don't seriously think I'll be going over 130 M.P.H. very often, even on the track, so I'm not worried about the top end too much.

Adam

 

[honestabe]

Anybody?

 

[Nick M]

Well, you need to multiply the individual gear times the diff ratio to get your true reduction. That will tell you how far you are off.

 

[Jeff Lange]

It's almost exactly 10% for RPM increase at the same speed.

 

[honestabe]

That's what I thought. The only thing changing is the diff. The tranny gears are staying the same. Atleast I'll be able to use 5th gear better at higher speeds (who knows, I may actually be able to get my car into 5th before I hit the limiter at 118, although I doubt it.

Adam