For Manual Transmissions Only

The factory torsen center differential in the S4 and A4 provides a 2:1 torque distribution between front and rear. What does this mean? This enables the end of the car that still has traction (most of the time the rear) to deliver double the torque to the tires with traction. Our experience has proven that this closer to even distribution is best for drag racing. So this modification is not for you if you are into drag racing primarily. However for Auto Crossers, Road racers and others who prefer the twisties JHM recommends a bias ratio of 4:1. This is the same bias ratio that Audi has provided in the stock RS4 driveline.

So if you are tired of going through corners while using a lot of throttle and still getting "understeer" then this product is for you and will help you get a little more "oversteer" and allow you to drive the car a little more like a RWD car but still have the superior control of AWD.

NOTE: PROFESSIONAL INSTALLATING HIGHLY RECOMMENDED. WE ARE OFFERING THESE SHIMS SEPERATELY DUE TO DEMAND. THESE SHIMS DO NOT COME WITH A WARRANTY UNLESS YOU PURCHASE OUR 4:1 DIFF UPGRADE DUE TO THE INCREASED CHANCE OF INSTALLATION ERROR.

NOTE: THESE SHIMS ARE PRECISION MACHINED AND HARDENED AND EXCEED OEM QUALITY. USING STANDARD WASHERS OR SHIMS YOU FIND ON THE INTERNET IS A SURE WAY TO DESTROY YOUR EXPENSIVE DIFFERENTIAL.