Big Brake Upgrades via the BMW G series catalog

[Z4m40i]

The rotors shouldn’t affect clearance as the caliper carrier bracket is the same for both non M and M series cars. Because of this, there shouldn’t be any offset difference between non M and M rotors. With that being said, I am running a riveted rotor from a non M car and NOT the pin drive style M rotor.

it’s really odd, it’s almost as if you don’t have the rotor fully seated on the hub. A stock caliper bracket won’t align with the mounting points because it’ll contact the rotor, not an offset gap seen here.

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[DarkZupra]

I spent a bunch of time trying to figure out what happened yesterday. It appears that the M rotors have a much lower "offset" and are much flatter, so the calipers sit closer to the wheel face. Non-M rotors sit back much further.

For now Ive ordered some cheap 370x24 rotors for a G30 to test the theory. One of the aforementioned companies that creates a front caliper adapter also sells one for the rear, so I have reached out to them to see if I can get those separate (as I dont need the full set) - https://www.ebay.com/itm/296842835809. Ill follow up with my findings here.

 

[Z4m40i]

Shoot, you’re right. There is an offset difference of approx 2.6cm. I guess the rear wheel hub is just different on the M cars.

this was a good find, but I’m sorry you had to figure it out like this

 

[DarkZupra]

Shit like this is never simple, and if youre the first person to do it, its even worse!

Good news is fronts fit great. We will see how the new rear rotors fit when they arrive and if I can get the adapters so I can use the full M rotors laters.

Edit - Since the 26.7mm difference is 1.05", I wonder if two 1" spacers would work, or if thats a stupid idea...

Edit 2 - Someone tell me if this is a horrible idea - https://www.amazon.com/Aluminum-Unt...ng-Spacers/dp/B09TY65KCM?ref_=ast_sto_dp&th=1

 

[nanaisu]

Shit like this is never simple, and if youre the first person to do it, its even worse!

Good news is fronts fit great. We will see how the new rear rotors fit when they arrive and if I can get the adapters so I can use the full M rotors laters.

Edit - Since the 26.7mm difference is 1.05", I wonder if two 1" spacers would work, or if thats a stupid idea...

Edit 2 - Someone tell me if this is a horrible idea - https://www.amazon.com/Aluminum-Unt...ng-Spacers/dp/B09TY65KCM?ref_=ast_sto_dp&th=1

Of course it's a horrible idea! But...

 

[GravyTrain]

The OEM M-Performance rear rotor for the G11 / G30 should bolt up; it's part of the kit @ Z4m40i mentioned in his first post. It's a two piece (non floating) 370mm rear rotor with a directional dimpled pattern that coordinated with the drilled pattern of the M front.

Rear left: 34216878179
Rear right: 34216878180

I'm new here and just picked up a Z4, interested in performing this hardware upgrade in the future.

 

[DarkZupra]

Im not sure what site you guys are using to check these measurements, but can you check the x3m rear rotors? Im starting to think those are what I need.

 

[speedlimit]

For those of you that went with the G80 calipers, has there been any noticeable change in pedal feel? Part numbers seem to be the same 34336892205 as far as I can tell.

 

[razorlab]

Im not sure what site you guys are using to check these measurements, but can you check the x3m rear rotors? Im starting to think those are what I need.

https://web.tecalliance.net/otto-zimmermann/en/home

 

[razorlab]

The OEM M-Performance rear rotor for the G11 / G30 should bolt up; it's part of the kit @ Z4m40i mentioned in his first post. It's a two piece (non floating) 370mm rear rotor with a directional dimpled pattern that coordinated with the drilled pattern of the M front.

Rear left: 34216878179
Rear right: 34216878180

I'm new here and just picked up a Z4, interested in performing this hardware upgrade in the future.

Yup, AFAIK, the "M-Performance" brake/rotor package of 395 front and 370 rear is what the X3M/X4M uses as well. X3M and X4M don't get the "real" M 6 piston front calipers, they use the 4 piston.

@DarkZupra

 

[DarkZupra]

https://web.tecalliance.net/otto-zimmermann/en/home

Thank you.

Yup, AFAIK, the "M-Performance" brake/rotor package of 395 front and 370 rear is what the X3M/X4M uses as well. X3M and X4M don't get the "real" M 6 piston front calipers, they use the 4 piston.

@DarkZupra

It looks like the x3M uses a 2 piece riveted rotor just like the M3, but with a different offset. Ive ordered an M550i rotor, an M performace rotor, and an X3M rotor. I WILL figure this out

 

[Z4m40i]

The rears do

For those of you that went with the G80 calipers, has there been any noticeable change in pedal feel? Part numbers seem to be the same 34336892205 as far as I can tell.

In my experience they are significantly better than the standard 348mm and 374mm 4 pot brakes. With castrol SRF and g-loc r16 or r18 pads, brake fade hasn’t been an issue the last 14 track days I ran this year. They’re incredibly confidence inspiring, even after putting a shit ton of heat into them. Unfortunately, they do discolor nearly as easily as the 4 pots. Now vs new.

 

[Keemaca]

@DarkZupra What made you decide to ditch the SW calipers?

 

[Maki2282]

The rears do


In my experience they are significantly better than the standard 348mm and 374mm 4 pot brakes. With castrol SRF and g-loc r16 or r18 pads, brake fade hasn’t been an issue the last 14 track days I ran this year. They’re incredibly confidence inspiring, even after putting a shit ton of heat into them. Unfortunately, they do discolor nearly as easily as the 4 pots. Now vs new.

I'd like to know if the G80 brakes fit the Supra without adapters? And if not, where can I get the adapters? Thanks.

 

[razorlab]

I'd like to know if the G80 brakes fit the Supra without adapters? And if not, where can I get the adapters? Thanks.

Maybe read this thread that literally explains it all?

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