Bavarian Motorsport Performance Differentials

Most German production vehicles, BMW included, are built with a relatively high differential gear ratio. This is mainly done to satisfy the Autobahn pilots of Germany. Since Autobahn speeds average approximately 180 km/h the vehicles are geared to operate at a fairly low engine R.P.M. for that rate of speed. As our speed limits are set at 100 to 110 km/h we rarely see the opportunity to drive our cars at their full European Autobahn potential.

By reducing the differential gear ratio we can experience a tremendous improvement in acceleration, both City and Highway driving. This modification is used by all of the European tuners to even further improve the performance of an engine modification package.

In most cases top speed would suffer less than 10%. On vehicles with performance modifications and increased rev. limits top speed reduction would be negligible. All BMW performance differentials include replacement ring and pinions, new bearings and seals. All limited slip units with the standard 25% lock-up units.

E36 325i/323I/328i/M33.0 1992-1999 ALPINA Differential Cover

In any track driven BMW Cooling the oil is a must. Endurance racers verify this point.
On track events our BMW technicians found a half-hour event on the track is enough for oil to thin out and leak through the BMW differential's vent hole. Top Grade Oil Combined with the fins on the bottom of the cover, your differential will be significantly cooler and thus, will last longer.
BMW uses a very similar cover on the E39 M5, E46 M3, and M Coupe/Roadster. Includes Orginal diff cover mounts, zinc-plated hardware, and a port for installing an e36 ALPINA Digital Cockpit temperature sensor.

M Roadster Finned Differential Cover Upgrade for 1984 -1992 e30 325 / e30 M3 / M Roadster

This factory finned differential cover bolts directly to the E30 diff housing. This is a must for track cars with limited slip differentials. The clutch packs in these diffs generate a lot of heat, the more heat you can dissipate the better. The fins on this cover will do just that. This is an inexpensive upgrade that may save you a lot of money down the road. Plus it looks cool. Kit includes diff cover, gasket and all necessary hardware.

Street & Track Differentials

Bavarian Motorsport differential units have proven to make as much a one second per mile difference in lap times on road courses. We can provide you with the unit for your own installation, or install it here in our facility. The picture below is an example of one of our differentials fifted to our customer's Supercharged E46 330i with a 3.91 final drive ratio.

"Alpina Bavarian Motorsport is in no way affiliated with Alpina GmbH Germany or BMW AG Germany"