Date: Mon, 19 Oct 1998 13:34:09 -0700
From: "Chris Brandt" <Chris.Brandt@nike.com>
Subject: re:e28 M5 RL/BB

A question for those in the know. I have been following some of the e28/e32 brake swap threads the last week or so. I will do this upgrade on my 85 635...The question I have is how do the e32 front brakes compare with the e28 M5 front brakes. The components look cheaper to replace and would be easier to get. Not to mention I would have two cars with all the same components...If the e32 front stuff is better than the e28 M5 stuff I might trickle the M5 stuff down to the coupe and do the upgrade on the M5.

If you can find a set of E28 M5 (or E24 M6) calipers resonably priced, go with them on your car. Forget about buying the calipers new...they're expensive. Rotor diameters are the same and many M5 owners are already using E32 rotors as replacements. My choice would still be the E32 calipers which take a larger pad than the M5.

The E34 M5 does have 15mm larger diameter rotors than the E32 but caliper clamping force and pad surface area are the same. I think BMW invented the bigger rotors for the M5 to more or less fill out the opening in the 17" wheels. If they were serious about stopping, they would have gone with large fixed 4-piston calipers on this car. Even the late Euro M5's with the Nurburgring brakes and massive rotors have pathetically undersized calipers....and the price for these brakes puts it up there in the RD & Schnitzer category (around $4k). SD