[kemiksiz]

Hi Folks,
I'm just spicing up my build (you may click in my signature) and I wonder if we can bolt on the M8 brakes?

I have done the 850i brakes on (395mm w/4 pistons) but I'm tempted by that M8 set and rears are 380 which is a very good improvement on visuals and performance I believe

When I have done the F30 - F80 conversion, the M3 brakes could not be bolt on. You have to make new arms for the mounting process so I went for the 370mm M perf ones, I did not want to risk anything.

But on G20 I know G30 395mm M perf brakes are bolt on, so any chance for the M8 ones, any ideas or experiences?

Thanks a lot

[kemiksiz]

Originally Posted by blau3er

M8 would not be bolt on - it would require a custom adapter to mount the caliper onto the hub.

The ///M discs bolt on, but the retaining screws do not line up.

If you want ///M discs, then you can fit X3M / X4M discs to your car with the 395mm caliper you have - however, again, the retaining screw doesn’t line up.

Found that one;

What do you mean by "the retaining screw doesn’t line up"?
So can it be done or how can it be done?

Thnks a lot

[TheDudeMan]

Originally Posted by kemiksiz

Found that one;

What do you mean by "the retaining screw doesn’t line up"?
So can it be done or how can it be done?

Thnks a lot

The retaining screw holds the rotor to the hub - not a critical component. My concern would be the backspacing for the caliper itself It's a lot bigger and will and as result will not center over the caliper, even with the correct rotor. Why not run the M340 performance brakes?

[kemiksiz]

Originally Posted by TheDudeMan

The retaining screw holds the rotor to the hub - not a critical component. My concern would be the backspacing for the caliper itself It's a lot bigger and will and as result will not center over the caliper, even with the correct rotor. Why not run the M340 performance brakes?

I think you mean the allingment screew, in the picture? Without it, the lugs will do job if we carefully lock them, right?

On the other hand, I'm already using 395mm 850i brakes, so m340i is not an option for me. I'm doing a G80 M3 conversion, you may check it from my signature as well

What about the REARS of X3m / X4M ? same calipers with the 850i calipers? Can I just buy the rear discs in that case?

Sorry bunch of questions around

[kemiksiz]

Originally Posted by blau3er

I recently bought a full set of F97 X3m brakes to sell on, however I thought it might be of use to share this info incase anyone is looking to go for a [relatively speaking] cheap BBK kit made entirely of OEM parts.

What you see here are a set of Brembo 4 pot calipers in 395mm variation with ///M compound brake pads of the ///M pin drive semi-floating discs.

I have a G20 hub as I have previously used it verify other brake fitment options, so I popped the calipers and discs on to see what was what. The good news is that its effectively a plug and play set up. It all lined up perfectly, with the calipers bolting down without any interference from the knuckle. The discs fit on the hub and there are no issues with alignment, except for the disc retaining screw, which must be different on the F97 hub.

Essentially this could be a pretty good set up for G series owners, as its not just the G20 that this would work on. M compound pads and discs coupled with the far superior looking 395mm caliper body is a winner!

Pics:



Pad sweep identical to OEM fitment on X3m.





The only known issue; brake disc retaining screw does not line up



Perfectly seated on G20 hub, no issues with CB or PCD alignment



Fitment detail





G20 hub for reference



Not much meat left on the hub to facilitate re-drill for disc retaining screw

I think we can lock the thread, I am upgrading mine with X3M setup 👍🏻

[Boosted6]

I am assuming you are doing it without the retaining screw?

[bimmerstar]

as a bump to this thread, I am looking to either upgrade to the F90 M5/M8 brake setup or the X3m F97 setup. Did the X3m F97 setup clear with 19" wheels? I am worried with the F90/M8 setup not clearing all 19" wheels. But i really like the 6 pots from the F90. Any one done testing?>