Roadfly.com         Roadfly Home | Features | Car Review Videos | Car Reviews | Cars For Sale | Used Car Parts Classifieds | Forum | Car Review Archives | Forum Archives Index



PDA



carbonragtop
08-05-2003, 08:58 AM
...thinking of changing over to 3.91 differential;

Local firms who'd do the job are:
1.)Dinan quotes $1999 parts + labor
OR
2.)***************.com at around $2800 complete job

would appreciate
any input on the specific change in MPH per RPM (if I weren't
so intellectually lazy I could probably work the existing numbers
backwards to arrive at a formula)

or if anyone who's installed 3.91 just a seat-of-the-pants assessment
on the change in the car's behavior.

cbailey781
08-05-2003, 10:21 AM
Diff ratio compare:

3.64 vs 3.91 @ 8000 RPM

Left column 3.64 and right column 3.91

approximate numbers are..

1st 40.25 mph 37.47 mph
2nd 67.30 62.65
3rd 101.95 94.91
4th 138.43 128.87
5th 170.26 158.51
6th 205.14 190.97

Drive force = constant * torque@RPM * gear ratio * differential ratio * transmission/wheel radius

3.91 diff ratio yield about 6.91 % increase in drive force<br>


<img src="http://members.roadfly.com/cbailey781/signature.JPG">

carbonragtop
08-05-2003, 11:48 AM


Roadfly Home | Car Reviews | Forum Archives Index