Rear Disc Brakes

[Guest Anonymous]

I am exploring the possiblity of converting my rear brakes to discs in hopes of improving braking on the track. Several posts have mentioned the use of VW rotors and the need to modify the hubs. I obtioned a VW rotor and was suprised to find that the centering hole in the rotor is larger than the coresponding part of the hub, so it cannot be used for centering, but that the overall hub diameter is too large to fit into the rotor. Is the rotor mod reducing the outide diameter of the entire hub (ie outside the studs)? Any help would be appreciated.

[Guest Anonymous]

...to machine the hub so that it fits and centers the rotor from the inside. Early front VW rotors will works, but you should also check front 318i (1984/85) discs as they are bigger in diameter (10.25 vs 9.5 inch) and can be had as scrap for test fitting at your local independent BMW shop.

[Guest Anonymous]

Lee - Thanks for the feedback. When so say to machine the hub to fit the inside of the rotor, I'm assuming you mean the outside of the hub, not the center of the hub where the drum is centered on the hub. The rules allow the rotor to any size up the size of the front (256 mm), so a turned down version of the 318 may be the trick.

[Guest Anonymous]

(nt)