In Reply to: Who has done Kormann diff. ratio change (more)? posted by Krit on June 22, 2000 at 01:23:59:
That was me. I have an M3aC, with the auto's stock 3.38:1 ratio. I swapped that for a 3.73:1. Costs were as follows:
$450 freight (overnight from CA -> NC -> CA)
$290 R&R rear diff
$272 R&R gear set
$650 3.73 gear set
$160 misc parts
The change was immediately apparent to me. The car accelerated noticeably faster off the line, and the shift points moved down. Testing using a G-tech showed a .45 sec improvement in 0-60 times (from 5.65 to 5.2) and a smaller improvement in the 1/4 mile. All in all, a very worthwhile modification.
IMHO, Korman did an excellent job both in the turnaround time (5 hours to do the job, received the diff in the morning and put it back in the mail in the afternoon) and in the quality of work. I'd recommend them without hesitation.