Why e34 brake life/perf better than e28?

[Gene in NC]

Thinking about replacing "85 e28 535 front brakes with e34 front setup. My experience says anything but stock e28. E28 vs e34 results below.

'85 e28 got less than 50k on new ATE rotors and Metal Masters. Pass side rotor seems to have a high spot and grooves. Did sit for about 10 months waiting for UCAs. After UCAs front susp felt like it was coming off the car. Had to replace very bad idler and worn pass tierod. Helped a lot but some rotor type shake still there.

'89 e34 525 got 100k on same (ATE/MM) rotor and pad setup. Had bad idler and pass UCA ball joint so bad that it rattled. Little or no shake. Replaced UCAs and idler. Rotors so clean that only needed pads.

If e28 needs rotors and pads anyway, I'd like to get performance/cost effectiveness like the e34 for the small addnl cost of calipers.

[BMWCCA1]

Just a thought but sitting for ten-months does not a valid comparison make. Most rotor "warp" is not from warping but from surface problems like rust or pad goo from sitting. Couldn't really tell if you had a brake shake problem before the car sat. MM's are made in so many different countries under so many different labels you can't say for sure that the same pad material is in play on both cars even if the box is labeled the same. Also, I've had very poor luck with Ate rotors on my E28, even Brembo rotors sucked using E34 rotors and E28 M5 calipers. I'd try and stick with Balos if you can, or whatever brand come from your local BMW dealer. They always seem to work better.

[Gene in NC]

BMWCCA1, thanks for the tips. Maybe e34 rotors not enough meat for those e28 M5 calipers.

[Gene in NC]

PADS in my "test" were PBA Metal Masters on both cars. Would expect some consistency within a single supplier. However, the original problem that led to UCA replacement on the e28 may well have been rotors.

Shoot!

[Gene in NC]

E32 seems to be the most popular replacement for e28 fronts. Would e34 work as well?

[winfred]

e32 is a thicker rotor with wider vents, e34 would also work just less of a heat sink, same sweaped area and pads

[Ross]

50k on brakes, what's the problem?