AudiWorld Tech Articles

Tech Article Title	Author	Date
996 Porsche brakes on 20V 90 Coupe	90quattrocoupe	2005

These are the pieces needed for upgrading a Coupe brake system to use Porsche 996 brakes. This model caliper comes on two different cars, the Porsche 996 or the Boxster S. The 996 brakes are black and the Boxster S brakes are red. You can also get these brakes in silver.

In order to run this set up, you will need to change you hubs from the standard 4X108 hub to the Euro 5X112 S2 hubs. There are other hubs you can use, but this is the easiest bolt up solution.

Hub carrier with S2 5X112 hub installed
Porsche 996(BoxsterS) caliper
RS2 caliper carrier
314X30 Euro A8 rotor (Audi part #441-615-301AA)
323X30 A8 rotor (not shown) (Audi Part #4D0-615-301A
Carrier to hub bolts - M12X1.5X22mm cap bolts with washer
Caliper to carrier bolts - M12X1.5X72mm hex bolt (standard BoxsterS bolt)

This is the caliper in its standard Porsche setup. This caliper is used with a 28mm wide rotor. You will need to file down these pins, because they are too close to the 30 mm rotor used in this conversion. You need to file about 1mm off. This will give you 2mm clearance on each side of the rotor. This will allow for heat expansion in the rotor

S2 hub installed on the coupe strut. The Coupe hub carrier is same as early S2 3B carrier. The bolt holes for the hubcarrier to strut are 12mm.

On the later S2/ABY cars, the hubcarrier to strut bolts are 14mm. If you buy the hub with the carrier you should be aware of this. You can ream the coupe strut holes out to 14mm to fit this hubcarrier. This is what I had to do.

This picture shows the RS2 carrier installed on the hub with the M12X1.5X22mm cap bolts

This is a picture of the A8 314X30 rotor installed on the S2 hub. You need to hold it in place with a couple of lug bolts.

The Porsche 996 caliper bolts right up to the RS2 carrier with the M12X1.5X72mm hex bolts and fits evenly over the rotor. Spin the rotor and the caliper carrier pins do not hit, even before they are filed down.

Brake pads are installed in the caliper using the center pin and spring plate. There is a cotter pin holding the center pin in place.

This picture shows the A8 314X30 rotor from the side. The pads in the caliper so not quite cover the sweep area of the rotor. The pads stick out about 1.5 mm above the radius of the rotor.

The A8 323X30 rotor has all the same dimensions as the 314, but is available in the states. It fits the same as the 314s. If you compare the picture below of the 323 rotor vs the picture above of the 314 rotor, you will notice the pads sit more centered on the rotor.

The rotors have the same offset dimension. The only difference in the rotors is the diameter.
This is a bolt up installation for the USA coupes. For the brake lines you can change out the hard line that curves around the strut and the flex line from the strut to the caliper. You can change this to a pseudo RS2 hard line. You buy a already made 400mm line from VW and bend it to the new caliper. You don't need a flex line from the strut to the caliper, because the Porsche brake pads pull out of the top of the caliper.

Greg