F82 M4 brakes on an E86 Z4. Doable?

S

Scooby216

Member
Hello everyone! 👋🏻
New to the forum and new to the Z4. In fact, I haven’t bought one yet! 😂

I’m looking to buy an E86 Z4 Coupe and prepare it for track use (whilst remaining road legal). An area I would like to make sure is up to the job first off is the brakes. I have available to me a set of front callipers and discs off an F82 M4. Does anyone know if these will fit? Or if there are any adaptations available to make them fit?

Thanks in advance for your help. :)

Cheers,
Scooby.
 
I'll jump on that one as I have recently gone down a rabbit hole about brake swap ideas.

Basically I came across and realised big Range Rover calipers are cheap in comparison to BMW options or aftermarket BBK. On top of that discs PCD and hub diameters are compatible, at least for front. Digging more into that I realised the big calipers are really massive and would need at least 19" wheels so I gave up but still looked at options thinking I could find a way to make a BBK on the cheap with limited modifications.

Conclusion is: Yes F20/F30 and matching F80 calipers are supposed to bolt straight to our hubs BUT the disc offset from F30 and F80 is too much (73mm vs 53mm) , someone played with it here: https://www.e46fanatics.com/threads/e46-full-f30-f-r-brembo-big-brake-conversion-non-m.1313278
On top of that, bolting the 370/380 caliper straight on our hubs should result in a fitment for a 370mm disc from F30 not the 380mm from F80.

After scanning through the Brembo website what I concluded could be a fairly good match would be a 363mm disc from Disco 5 / New Defender and an F30 caliper but from the 340mm disc with a braket to adapt to the slightly higher offset from the disc (62mm vs 53mm, which I am not sure would actually clear the hub) and diameter (idea being to use a 340mm caliper pushed out for a 363mm disc). A key push for that disc choice is that it could take the full pad swept area contrary to other options tried here where pads had to be chamfered: https://www.e46fanatics.com/threads/f30-m-sport-brembo-big-brake-install.1075669

For the rear, the F30 caliper for 345mm disc should bolt straight on (seen in a link above) but once again offset are an issue. Best match should be an E65 rear disc but would require changing the handbrake system from Z4 to E46 resulting in a drum diameter of 185mm instead of 160mm. Another option would be using F20 disc but it has less offset which might require caliper spacing and the handbrake shoes not being fully in the drum. On Z4M, rear offsets is much reduced and the opposit problem will appear.

I am not in a position where I need more brakes and can justify spending money and try all that but if someone want to built some track setup mostly based on OE parts that could be "affordable" without needing to heavily machine stuff; I'd like to see it done :driving:
 
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