M4 380mm brake rotors fits E92 m3 hub?

Hi , just joined so i can post this, i fitted these to my car back in August

Ok then, bought these back in August , a full set of F8* M3/M4 brakes , consisting of 370mm rear discs with 2 pot calipers ,380mm front discs with 4 pot calipers and also the front spindle/hub assembie's too, you need those for the front calipers as the pitch betwwen mounting lugs is smaller on the M4 as opposed to the E92 M3, I was assured from theseller that they would just bolt on so after many messages back and forth I took the plunge and bought them, I dont think anyone has done a detailed write up about fitting this brake set up so here goes

the full set along with spindles




so with the car on axle stands for a few days I stripped my front hubs/spindles off to compare to the M4 set.

back to back measuring to compare the centreline ,angle and height of how the damper will sit , its exactly the same










carefull measurements of the centrelines and angles of the balljoint holes, if this is different then its game over ! indeed they are exactly the same







Now this is the one where its slightly different, note the four holes for the wheel bearing , they sit around 4-5 mm lower on the M4 spindle, making the length from the strut top mount to the wheel centre 4-5mm longer, this will raise the car's ride height ever so slightly, we'll see later on!



also the E92 wheel bearing fits exactly to the m4 spindle, i tried it off the car first then bolted the disc on and caliper, its plug and play with no altering of the track ,the wheels sit exactly the same and i still use my 10mm spacer with no ill affect.

old spindles and front arms removed for cleaning and painting


removing bushes ready for powerflex items



painted








spindles cleaned up ready for painting, can you see where this is leading to?





coat of 2k primer





painted silver




bushes fitted







arch liners cleaned up




back on and bolted up, I marked the damper with a line around the top of the old spindle , its the same with the M4 spindle



caliper on and bled






Rears now, I measures the thickness of the discs from the mating face to the inner surface, i can comfirm they're the measuremnt on both sets of discs, the rears are plug and play with the handbrake shoes lining up perfect too!




the only thing thats required for the caliper fitment is these spacer washers between caliper and hub to centralise the caliper on the disc






caliper bolted on and bled



use also use the E92 brake hoses as theyre a direct fit










Also fitted these, a set of competition pack springs

this is how it sits with the comp pack springs and m4 brakes






I'd say its a little high in the front ,maybe due to that measurement I talked about earlier, making the centre of the wheel to the strut top 4-5mm longer due to the wheel bearing mounting holes, it was on eibachs for a bit and looked good with them fitted but the comp springs handle far superior!

bought some used Intrax springs , have to say they handle really well but a very hard ride, this is how it looks with those fitted, I think the drop is a bit low, even with the M4 spindles!



















so to conclude , Im happy with the M4 brake set up, a nice solid feel with no exceess pedal travel the some BBk's can give, only thing is im looking for the holy grail of springs to give me that perfect stance with comp pack ride/handling , dont say eibachs as ive had those, KW has set maybe on the cards!
would i reccommend the M4 set up ? Yes! allthough I may paint the calipers Austin yellow one day!