With much anxiety I bought a 2.82 rear dif and lowering springs (See a different post for that upgrade.) from Carl at BergWerks. The rear dif was $1295 (Non ASR.), the speedo gear was $150, freight was about $85, and labor ended up at $350. So total cost was about $1900.

I can't imagine another upgrade that would make so much difference! The original rear dif was not well matched to the motor's powerband, which is rather peaky. Good power starts at about 3000rpm, and gets really strong at 4000rpm. While the original rear dif made for economical highway cruising (27MPG!) it made the car very sluggish off the line. And when cruising around town, sometimes two downshifts were required to get the motor in the powerband. And there were other times when the tranny was close to a shift but would decide not to, so even with 275HP on tap, acceleration could be wimpy. With the original rear dif a strong 4-3 downshift on the highway occurred at about 75MPH.

The new rear dif provides for much quicker starts from a standstill, and allows the motor to stay closer to it's powerband all the time. The 4-3 downshift now happens at about 55-60MPH, and it is a much stronger push than before. The car feels much more lively all the time, and is much better matched to the motor's power characteristics.

Carl estimated that the 0-60 time would come down about .5 - .6 seconds, and I definitely believe it! The entire nature of the car has changed from a rather sedate family sedan with a decent high end rush to a very strong V8 with lots of go on tap all the time. Mileage does not appear to have suffered too much. Whereas I used to average about 22MPG in combined city and highway, I am at about 20MPG. (And I am definitely not being gentle driving around!)

In short this is an incredible upgrade for the money! I can't imagine a supercharger, turbo, NOS or any other upgrade providing as much bang for the buck as the rear dif swap. If you have stock 15" X 195 tires, you may over whelm them, however. I have 16", 205's, and I think they help keep the motor from spinning the rears too easily.

Please email or post if you have any questions!

Thanks -

__________________
Mike in Denver
'93 400E Now DEAD - Rear ended and totalled.
Replaced by '02 C32 AMG - FAST!