Posted by Gregory Bradbury on November 27, 2003 at 06:53:48 from 195.141.59.2
In Reply to: brake upgrade early E12 >76 (long) posted by Zolka on October 31, 2003 at 02:56:24:
Hei Zolta,
I know your SU FI Club's webmaster (Samuli) so say hei for me. For upgrades on the E12 brakes, there are a few choices depending on the year of the car you have and how much stopping you want.
Early (72 to mid 76) cars have a front hub that requires you to remove the disc from behind the hub (you need to remove it from the car). This version attaches the disc to the hub with four or five bolts. If you have solid discs, you change to early vented 528i discs, use the 528i caliper pin kit and add caliper spacers and longer bolts (source comes later OR buy exchange Ate calipers for an E12 528i and give them your old ones for cores. This disc is 19 mm thick (vented front up to mid 76) and is the same as the E3 or E9 with vented front discs.
Later (mid 76 to 81) cars have the disc held on by a single allen key bolt. THE ultimate upgrade for this car is to use the M535i / 745i front disc and the thicker M535i caliper pin kit and add caliper spacers and longer bolts. This disc is 25 mm thick and specially heat treated and stress relieved vs. a 528i vented disc that is only 22 mm thick. 528i calipers will not work with the 25 mm disc. You can find the caliper bolts & spacers one some E23 cars (measure the caliper spacer FIRST) OR buy exchange Ate calipers for an E12 M535i and give them your old ones for cores.
If you want to know more or have trouble finding parts, I can help. Switzerland is good for these things.
For the rear, it is possible to upgrade to vented rear discs, I can detail this if people are interested.