Korman Adjustable Short Shift Kit

• Adjusts in minutes from inside your car

• Accepts original or aftermarket gearshift knobs

• Assembled unit saves on installation time

• Adjustment locking mechanism

• Replaceable, self-lubricating bushings

• Includes shifter cup bushings and complete instructions

• Easily installs in less than an hour

All E30 M3's P/N 25250001

Lightweight Flywheel

Precision machined and balanced steel flywheel. 35% lighter for reduced inertia and more rapid acceleration. The flywheel and ring gear are machined from one piece of steel for greater strength and lower weight. As supplied by BMW on the Evolution 2 and 3 M3's. Weight is 12.5lbs.

P/N 11220003

Sachs Heavy Duty Sport Clutch Kit

Includes spring loaded disc with heavy duty lining, a heavy duty release bearing which features a strong aluminum housing (OEM is plastic), and a heavy duty pressure plate. Components also available separately

P/N 2151151020

Sachs Heavy Duty Light Weight Clutch Kit

As above but the center part of the clutch plate, normally cast iron, is replaced with a hardened aluminum plate with  a bonded friction surface. The reduced inertia forces enable quicker acceleration. Unbeatable when combined with our Light Weight Flywheel. Components also available separately

P/N 2151151021

Heavy Duty M Release Bearing

As used in our clutch kits, above.   Aluminum housing instead of plastic.  P/N  21511510019

Close Ratio Gearbox

A popular option on European M3's, the five speed close ratio provides quicker acceleration through more optimum use of the M3's power band. There is no overdrive like the U.S. unit. Fifth is a 1:1 ratio. A direct bolt in on U.S. specification M3's. We recommend changing the final drive ratio when using this transmission.

P/N 23001221372, Core Charge P/N 2300M3CORE

Korman M3 Gearbox Rebuild

We rebuild your gearbox using only BMW original parts. Includes new bearings, synchronizers, seals, gaskets and labor.  2 year/24,000 mile warranty.

P/N 23231800

Quaife Automatic Torque-Sensing Limited Slip Units

Already used in Formula 1, IMSA, SCCA and Pro Rally applications, Quaife Automatic Torque Biasing Limited Slip Units are now available for your BMW. Quaife units utilize a gear driven mechanical process to direct power at an infinitely variable rate (as opposed to a fixed 25%, 40% or 75% rate) to the wheel with the most traction. Unlike the more complicated and fragile Torsen design and the BMW OEM clutch pack limited slip units which tend to transfer power abruptly, the Quaife units are simple and rugged in design and provide a very smooth power transfer between the two driven wheels. Quaife 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.  P/N 33146900

Korman 50% and 75% Limited Slip Differential Conversions

If you race, autocross, rally, do BMW driving schools, or otherwise tend to push your car to the limit, let us convert your 25% limited slip differential to 50% or 75%  limited slip. Wheel spin is reduced or eliminated, improving track times significantly. Additionally, the reduction in internal slippage lowers lubricant temperatures, helping prolong bearing life. The conversion requires special machining at our facility, making it necessary for you to ship your differential to us for modification.  Your salesperson can help you decide which percentage is right for you.

75% Limited Slip Conversion P/N 33126375 

50% Limited Slip Conversion P/N 33126350 (price when done with gear change, rebuild or similar)

Korman Standard Differential Rebuild

2 year/24,000 mile warranty

Differentials with normal wear don't usually require the replacement of the ring and pinion gears. Our standard rebuild includes complete disassembly, through cleaning, close inspection of all parts, replacement of all bearings, seals gaskets, crush sleeve and lock ring. Includes meticulous attention to correct gear lash, gear contact, precise pre-load of bearings and exact torque specifications. We expect our rebuilds to last well over 100,000 miles. Note: UPS can pick up and deliver your differential at your door!

Standard Diff Rebuild P/N 33126030

Rebuild with 75% Limited Slip Conversion P/N 33126475

Rebuild with 75% Limited Slip Conversion and 4.45 Gear Set P/N 33126030B

Rebuild with Quaife Unit and 4.45 Gear Set P/N 33126030C

Optional Gear Ratios

Korman Recommended Gear Ratio Changes

4.45 Gear Conversion

M3 stock gearing is 4.10:1. We recommend changing to a 4.45:1 for improved acceleration. This 8.5% change results in 0-60 times around 6.9 seconds (other modifications notwithstanding), more flexibility for spirited driving, and of course faster lap times at autocrosses and drivers' schools. You get quicker acceleration in every gear at all RPM ranges.

3.46 Gear Conversion

Korman's recommendation for best performance with our Close Ratio Gearbox.

Other  Available Gear Ratios-E30 M3

M3 Finned Differential Cover Kit

Bolt-on cover with deep cooling fins lowers differential temperatures and increases the service life of your diff.  Compatible with Delrin solid diff mount.  Kit is complete with special length bolts, gasket and drain plugs.  P/N  33112228335

Improved mounts reduce differential movement under heavy loads.  Use the hard rubber mount for street or track.  The delrin unit is not recommended for street due to transmission of noise into passenger compartment.

Hard Rubber Differential Mount P/N  3330109

Delrin P/N  331200325