Prompted by the recent thread discussing some brake options, I figured I should share my recently completed front brake upgrade.
I did a lot of testing with many different Brembo front calipers, testing blue calipers from an F82 M4 and F20 M140i. The M4 calipers can be made to work on E46 M3s, so the expectation was that they would work with the Z4M but alas the slight difference in steering knuckle meant it wouldn't work. The M140i calipers can be made to fit but would need a significant spacer so that the wheel spokes will clear the caliper.
In the end, I saw how nicely the E82 135i Brembo 6 piston calipers worked on another member's car and decided to stop giving myself headaches and go down the tried and tested route :lol:
I'm running the 6 piston Brembo fronts on the stock CSL rotors and the stock rear brake setup. Based purely on piston sizing calculations this will have adjusted the bias backwards slightly, however accounting for a more aggressive pad in the front I feel that there's no significant difference in the bias.
I had the new calipers and the stock rear calipers both painted a metallic blue, similar to the M4/M140i calipers, then M decals added and a clear coat. All high temp paint. At first I was unsure about drawing attention to the small real calipers, but justified it due to the fact that the F10 M5 has a similar setup: big, 6 piston calipers up front and little single pistons at the back.
He best thing is that a new caliper bracket isn't even necessary! They bolt straight up to the knuckle with some 8mm spacers and longer mounting bolts (the mounting bolts from the 135i are perfect). The spacers are basically M12 washers 8mm thick and 32mm diameter - I machined mine from some 304 grade stainless round bar. I also fitted some braided steel brake lines to the front calipers while I was at it
How do they perform? Well I haven't had a chance to give them a workout with a hard drive yet, but for day to day driving they feel fantastic! The pedal feel is improved but also still very "BMW factory" feeling, if that makes any sense. Still very linear.
I am familiar of reports of the ceramic part of the pistons fracturing on these calipers but in the very few cases I've heard of it has been restricted to cars under heavy track use. I'm not concerned, but worst case they need rebuilding one day.
I'll have a better idea/confirmation of the performance in heavy use in a couple of weeks but so far is proving to be a very satisfying upgrade. They look amazing and give the Z4M a more modern feel.
I did a lot of testing with many different Brembo front calipers, testing blue calipers from an F82 M4 and F20 M140i. The M4 calipers can be made to work on E46 M3s, so the expectation was that they would work with the Z4M but alas the slight difference in steering knuckle meant it wouldn't work. The M140i calipers can be made to fit but would need a significant spacer so that the wheel spokes will clear the caliper.
In the end, I saw how nicely the E82 135i Brembo 6 piston calipers worked on another member's car and decided to stop giving myself headaches and go down the tried and tested route :lol:
I'm running the 6 piston Brembo fronts on the stock CSL rotors and the stock rear brake setup. Based purely on piston sizing calculations this will have adjusted the bias backwards slightly, however accounting for a more aggressive pad in the front I feel that there's no significant difference in the bias.
I had the new calipers and the stock rear calipers both painted a metallic blue, similar to the M4/M140i calipers, then M decals added and a clear coat. All high temp paint. At first I was unsure about drawing attention to the small real calipers, but justified it due to the fact that the F10 M5 has a similar setup: big, 6 piston calipers up front and little single pistons at the back.
He best thing is that a new caliper bracket isn't even necessary! They bolt straight up to the knuckle with some 8mm spacers and longer mounting bolts (the mounting bolts from the 135i are perfect). The spacers are basically M12 washers 8mm thick and 32mm diameter - I machined mine from some 304 grade stainless round bar. I also fitted some braided steel brake lines to the front calipers while I was at it
How do they perform? Well I haven't had a chance to give them a workout with a hard drive yet, but for day to day driving they feel fantastic! The pedal feel is improved but also still very "BMW factory" feeling, if that makes any sense. Still very linear.
I am familiar of reports of the ceramic part of the pistons fracturing on these calipers but in the very few cases I've heard of it has been restricted to cars under heavy track use. I'm not concerned, but worst case they need rebuilding one day.
I'll have a better idea/confirmation of the performance in heavy use in a couple of weeks but so far is proving to be a very satisfying upgrade. They look amazing and give the Z4M a more modern feel.
