M4 Front Brake Caliper Retrofit

[Player 1]

As per the title really, I recently got hold of some front brake calipers of of an M4, tidied them up and repainted them before sticking them on the Z4. Unfortunately the M3/M4 discs don't fit however 370mm performance discs from a 340i/440i etc bolt right on.

It's still in the process of bedding in somewhat but the pedal does feel a little more solid, certainly feels as though there's a lot of potential there as they bed in properly.
The calipers themselves aren't that much larger then the old ones and so don't feel any different in terms of weight, if anything they are a bit lighter perhaps? Anything gained there is likely offset by the larger discs however picking them up side by side, I'd say there isn't that much between them.
The biggest difference is in the pads themselves as the contact patch on the M4 calipers is a lot larger than the original pads.

Very pleased with them so far, shall update when they're properly bedded in.

 

[Jollyjoiner]

I'm interested in this thread. So this sounds like they bolt straight on, does the caliper need the carrier too or is it a case of old off and new straight on ? As for the discs is there a year of car they come from ? same with the Calipers ?

Might need to start myself a search for some, I bet they a tidy price though

 

[Player 1]

They really do just bolt straight on, it actually took me more time to change the discs/pads on the back axle than the whole lot on the front! :rofl:

In the process of this I did find someone offering fully refurbished calipers at reasonable cost, perhaps if there's a number of people interested then I might be able to get some money knocked off of them and put some kits together as I can get a pretty hefty discount on the discs too.
At a guess I'd say I could put something together for around £900? I'd have to look into it properly to be honest but that'd cover calipers, discs, pads, new bolts and the wear sensor.
The discs and pads I used are TRW who are one of BMW's oe suppliers.

 

[Jollyjoiner]

They really do just bolt straight on, it actually took me more time to change the discs/pads on the back axle than the whole lot on the front! :rofl:

In the process of this I did find someone offering fully refurbished calipers at reasonable cost, perhaps if there's a number of people interested then I might be able to get some money knocked off of them and put some kits together as I can get a pretty hefty discount on the discs too.
At a guess I'd say I could put something together for around £900? I'd have to look into it properly to be honest but that'd cover calipers, discs, pads, new bolts and the wear sensor.
The discs and pads I used are TRW who are one of BMW's oe suppliers.

Mmmm sounds interesting. So I'm guessing they are off any year of M4 and any year of 340i/440i as long as they are 370mm.
Your pricing doesn't seem too bad.
I was going to put some Yellow stuff pads in mine and see how it felt but might have to give this some serious thought.

Cheers
JJ

 

[Player 1]

When researching I when on realoem and took part numbers off of a 2016 440i. I don't think it matters what year as long as its the 370mm discs however I can attest that 2016 works.
Likewise, any year M4 or F series M3 for the calipers, I believe the are the same calipers on the 440i however the particular ones I got hold of were from an M4 so used M4 part numbers for the pads.

I'll get in contact with some of the parts suppliers and see how much I can get them to cut prices down by too

 

[john-e89]

I'm interested in this thread. So this sounds like they bolt straight on, does the caliper need the carrier too or is it a case of old off and new straight on ? As for the discs is there a year of car they come from ? same with the Calipers ?

Might need to start myself a search for some, I bet they a tidy price though

Settle yourself down Nigel lad.....you’ve only just bought the piggin thing.... oke:

 

[Player 1]

More people need to fiddle with these cars John!
There's a surprising amount that can be done when looking into it

 

[john-e89]

More people need to fiddle with these cars John!
There's a surprising amount that can be done when looking into it

It’s a good upgrade definitely..

I’m putting Eibach anti roll bars on mine to try to stiffen the cornering up a bit. There’s a better car in there I think, just needs some careful tinkering. :driving:

 

[Nick9one1]

More people need to fiddle with these cars John!
There's a surprising amount that can be done when looking into it

It’s a good upgrade definitely..

I’m putting Eibach anti roll bars on mine to try to stiffen the cornering up a bit. There’s a better car in there I think, just needs some careful tinkering. :driving:

I'm not sure if its been mentioned on here, but its possible to swap out the upper and lower control arms on the e89 with e9x M3 front arms.
The M3 arms use a bearing/bushing arrangement instead of the rubber bushing on the e89. Camber is also increased.

 

[Angie4m]

Are you sure they were from a M4? Only reason I ask is they aren’t silver with BMW performance on them, they are blue with the M logo or yellow if they are ceramic. The M4 also takes 380mm discs not 370mm so is it that you’ve bought the BMW performance kit from a 3/4 series which takes the 370mm discs?

It’s a nice upgrade. Probably a good job they aren’t the M4 ones cause the discs alone are over a grand.

 

[MrPT]

Wow, that’s a fantastic upgrade if they just bolt on to the existing carriers. How’s the match from a piston area point of view? Amazing how small some of these multi-pots can be.

 

[Player 1]

I'm not sure if its been mentioned on here, but its possible to swap out the upper and lower control arms on the e89 with e9x M3 front arms.
The M3 arms use a bearing/bushing arrangement instead of the rubber bushing on the e89. Camber is also increased.

Already did that lot Nick, here's the thread of going about doing it;
https://z4-forum.com/forum/viewtopic.php?f=23&t=108512

I should probably do one big thread with everything I've done to this car :lol:

 

[Player 1]

Are you sure they were from a M4? Only reason I ask is they aren’t silver with BMW performance on them, they are blue with the M logo or yellow if they are ceramic. The M4 also takes 380mm discs not 370mm so is it that you’ve bought the BMW performance kit from a 3/4 series which takes the 370mm discs?

It’s a nice upgrade. Probably a good job they aren’t the M4 ones cause the discs alone are over a grand.

Sorry, I think you may want to read the first paragraph in my original post again. :wink:

I said the calipers were off of an M4 and I repainted them. I then put the bmw performance decals on there, I didn't want the 'look at me' blue and it's not an M car so didn't want the M decals either.
I found the M4 discs won't fit due to the different offsets, as such 370mm ones from the 440i were used.
Hope that clears it up!

 

[Player 1]

Wow, that’s a fantastic upgrade if they just bolt on to the existing carriers. How’s the match from a piston area point of view? Amazing how small some of these multi-pots can be.

Thanks! Now they've bedded in a bit more it's feeling better and better. There's a nice firm pedal which is easy to modulate, I did get a chance to do a bigger stop or two today and there's noticeably more stopping power from higher speed.
A bit of a first world problem but it definitely takes less pedal pressure to trigger the hazard lights :rofl:

It's hard to say what difference there is in piston area, for sure it's more but the single piston was a pretty big one! I'll take a look at the old caliper a bit more closely and let you know
The difference in the size of the pads is huge though, I'll get some rough measurements and figure out some percentages too.

 

[john-e89]

I'm not sure if its been mentioned on here, but its possible to swap out the upper and lower control arms on the e89 with e9x M3 front arms.
The M3 arms use a bearing/bushing arrangement instead of the rubber bushing on the e89. Camber is also increased.

Already did that lot Nick, here's the thread of going about doing it;
https://z4-forum.com/forum/viewtopic.php?f=23&t=108512

I should probably do one big thread with everything I've done to this car :lol:

Very interesting read on the M3 parts Player...something I’ll definately be doing.

I also wondered about using the line lock from PB brakes for fitting the whole M4 brake kit if the rears will fit too.

 

[Nictrix]

With the calipers from the M4 and as said normally a 380mm disc, what pads are used with the 370mm disc?
Or do the pads hang off the edge of the disc?

 

[Jollyjoiner]

When researching I when on realoem and took part numbers off of a 2016 440i. I don't think it matters what year as long as its the 370mm discs however I can attest that 2016 works.
Likewise, any year M4 or F series M3 for the calipers, I believe the are the same calipers on the 440i however the particular ones I got hold of were from an M4 so used M4 part numbers for the pads.

I'll get in contact with some of the parts suppliers and see how much I can get them to cut prices down by too

Thanks for your effort in this, some prices and lists of the correct parts to get would be great.

Cheers

 

[Jollyjoiner]

I'm interested in this thread. So this sounds like they bolt straight on, does the caliper need the carrier too or is it a case of old off and new straight on ? As for the discs is there a year of car they come from ? same with the Calipers ?

Might need to start myself a search for some, I bet they a tidy price though

Settle yourself down Nigel lad.....you’ve only just bought the piggin thing.... oke:

Says he thats has his the same amount of time and is doing loads of mods already :rofl: oke:

 

[Player 1]

Very interesting read on the M3 parts Player...something I’ll definately be doing.

I also wondered about using the line lock from PB brakes for fitting the whole M4 brake kit if the rears will fit too.

Good to hear! If you do it and any questions pop up, just give me a shout and I'll be happy to help

I did look into the rear brakes and I don't think there's anything that's going to swap over from other cars without fabricating adaptor brackets. If it wasn't for the electric handbrake it'd be a lot easier!

 

[Player 1]

With the calipers from the M4 and as said normally a 380mm disc, what pads are used with the 370mm disc?
Or do the pads hang off the edge of the disc?

When I looked on realoem there were two different part numbers for the M4 pad and the 440i pad at first however closer inspection showed that one supersedes the other and there's other part numbers that supersede that. In terms of size and shape, they are both the same though and both correlate to the same numbers from manufactures such as TRW and Brembo.