M4 380mm brake rotors fits E92 m3 hub?

[gazosnic]

Originally Posted by doogee

I can now verify the following:

Front requires 380mm M3/M4 rotors and a custom caliper bracket.

Rear caliper bolts up, but will require 370mm M3/M4 rotors.

Keep in mind I'm doing this for fun, I didn't pay a penny for the calipers so why not give this a shot. Maintaining front and rear rotor size from the F80 will keep balance in check. I have a contact who can make me a front caliper bracket. I track my car quite often so I'll be able to give some input on how the system works on the E9x. I'm assuming a small upgrade in stopping power and good balance. But we will see.

I'll more than likely end up with a proper BBK setup, but anything that allows me to swap pads easier is a plus. I expect the paint on the OEM calipers is probably junk and will burn/change color.

Here are some pics of a quick test fit on the rear (with e9x rotors):

Whats the size difference between stock e9x and f8x? Visually those rotors dont look much bigger.

[doogee]

Originally Posted by gazosnic

Whats the size difference between stock e9x and f8x? Visually those rotors dont look much bigger.

Each rotor is 20mm larger than e9x rotors.

[BMW3DK]

hi,

just to sum the learnings so far:

M4 breaks should fit on our E9x M3's under following conditions:

Front: M4 Rotors fit fine / Calibers need a new bracket

Back: M4 Rotors fit fine / Calibers are bolt on.


If this is correct, then my question is if there is a supplier of the needed bracket for the front calibers?

thx

// Chris

[doogee]

Originally Posted by BMW3DK

hi,

just to sum the learnings so far:

M4 breaks should fit on our E9x M3's under following conditions:

Front: Rotors are fine / Calibers need a new bracket

Back: Rotors are fine / Calibers are bolt on.


If this is correct, then my question is if there is a supplier of the needed bracket for the front calibers?

thx

// Chris

No you’ll need M4 rotors front and rear as well

[BMW3DK]

that was what I meant, now it is spelled out.

// Chris

Originally Posted by doogee

No you’ll need M4 rotors front and rear as well

[shwaara]

Is there any update with the rotors?

[MDMA 135i]

I fitted m4 rotors and m4 4 piston brake calipers on my 1m, i will upload pictures.

[doogee]

Originally Posted by MDMA 135i

I fitted m4 rotors and m4 4 piston brake calipers on my 1m, i will upload pictures.

I think you're right. I think the M4 caliper bolts up!

Turns out the front calipers I have are from a M235i, which has a slightly different bolt pattern.

[MDMA 135i]

Originally Posted by doogee

I think you're right. I think the M4 caliper bolts up!

Turns out the front calipers I have are from an M235i, which has a slightly different bolt pattern.

No i need to made custom brackets (brake adapters) but its very easy and simpe to made it. i will post dimension of custom brackets.

[MDMA 135i]

Originally Posted by doogee

I think you're right. I think the M4 caliper bolts up!

Turns out the front calipers I have are from an M235i, which has a slightly different bolt pattern.

On M235i you can not fit m4 rotors because M cars have different hub. You can fit F series performance rotors 370mm+m4 brake calipers. I think that setup is bolt on on F and E series.

[///MPower15]

Any updates on this? I have been thinking about doing this.

[Down_Shift]

Originally Posted by slicer

Or how about if you don't have the funds to do it right, go ahead and save your money, run the more than adequate stock brakes, refrain from building a Frankenbrake and don't worry what your friends think? I know that you are being sarcastic but you are supporting my point.

FWIW - I currently only have a front BBK and run upgraded lines and pads on the rear. Guess what? It is fantastic on the track. I'll be grabbing the matching Essex rear kit once released - but I must admit that it's not necessary.

On my previous car (e46 M3), I found a front Brembo BBK brand new, in the box, for $2,500. Ran that on numerous track days with upgraded pads and lines in the rear. Zero issues and saved some cash. I'm not suggesting that everyone needs to buy the best. I'm just saying don't spend your money on a "performance" mod that doesn't actually improve performance. Keep an eye on the used market for a BBK. There are often lightly used kits in the for-sale section.

Why are you wasting your time thread crapping another persons thread/topic?

OP and topic is legit. These are the types of topics that help progress our community.

All I got from your posts are

1) you are not a brake engineer
2) you spent money
3) you spent the time to click this thread. Read the posts and then type lengthy replies that are meant to shoot down someone?s idea.

I don?t see any justification on why you can tell anyone not to do something to their car?

[Down_Shift]

Originally Posted by roastbeef

there are 355mm "bbk" options and they are far less weight than oem brakes. some of the weight is from lighter calipers, some is from lighter rotors, and most is from using aluminum rotor hats.
in relative terms of braking tech- more mass in the rotors doesn't necessarily mean more thermal capacity. these rotors are designed to get rid of heat, NOT to hold onto it. so having a high "capacity" isn't important. getting rid of heat is more important than how much they can hold.
this is why i just shake my head and usually keep my fingers off the keyboard when i see these threads- or other threads about retrofits. people shunning the "bling" kits saying they are just for looks when they themselves are trying to move to something more aesthetically pleasing to the eye while burning money on a nominal upgrade when the rotors are by far the weakest link.
the amount of misunderstanding in this thread is mind boggling when there is so much good brake tech on this forum.

Originally Posted by dparm

Yes, many of them use 355mm rotors. I'm not sure they're lighter -- remember, more mass = more thermal capacity.

Originally Posted by roastbeef

there are 355mm "bbk" options and they are far less weight than oem brakes. some of the weight is from lighter calipers, some is from lighter rotors, and most is from using aluminum rotor hats.
in relative terms of braking tech- more mass in the rotors doesn't necessarily mean more thermal capacity. these rotors are designed to get rid of heat, NOT to hold onto it. so having a high "capacity" isn't important. getting rid of heat is more important than how much they can hold.
this is why i just shake my head and usually keep my fingers off the keyboard when i see these threads- or other threads about retrofits. people shunning the "bling" kits saying they are just for looks when they themselves are trying to move to something more aesthetically pleasing to the eye while burning money on a nominal upgrade when the rotors are by far the weakest link.
the amount of misunderstanding in this thread is mind boggling when there is so much good brake tech on this forum.

^

[slicer]

Originally Posted by Down_Shift

Why are you wasting your time thread crapping another persons thread/topic?

OP and topic is legit. These are the types of topics that help progress our community.

All I got from your posts are

1) you are not a brake engineer
2) you spent money
3) you spent the time to click this thread. Read the posts and then type lengthy replies that are meant to shoot down someone?s idea.

I don?t see any justification on why you can tell anyone not to do something to their car?

I'm "wasting my time" for the same reason the OP created his post. To help the community. I hate to see people waste their money on a modification that has no appreciable performance increase. The whole point of the forum is to share information, perspectives, experience; I'm doing just that. Ultimately, I con't care what others choose to do with their cars. What did you accomplish with your post?

[slonik]

oem rotors on m3e9x and f8x works really excellent. they are two piece and floating, and cheap enough.

but, oem calipers too small this cars (this size works good on 1200kg cars).


we have good results o oem rotors, when changing calipers on 6 pot brembo.

[doogee]

Originally Posted by slonik

oem rotors on m3e9x and f8x works really excellent. they are two piece and floating, and cheap enough.

but, oem calipers too small this cars (this size works good on 1200kg cars).


we have good results o oem rotors, when changing calipers on 6 pot brembo.

I find the calipers have more than enough power with a good track pad.

Total piston surface area between stock and most big brake kits is almost the same.

[r0cketm0nkey]

I actually emailed turner about their kit and they came back and said for the money, I should consider stoptech's bbk instead.

I lol'd. Basically they offer it but reluctantly I guess.

Plus it looks corny if you don't do the rears as well.

[slonik]

I find the calipers have more than enough power with a good track pad.

it's all about comparing.
enough for what?
i'm defining this very easily - how long time one pads set can run.
for example, f80 with oem brake system (iron rotors) can make about two track days on best pads you can take (ccr-g, pagid rs29 etc)
and after half of the season you get burned seals in calipers.
someone really calling this "enough brake system" ...

temperature is so high, that pads works very short time, they are simply burning in hard conditions.
easiest way to change it - use larger calipers. when we change oem calipers on 6 pot, pads works much longer time. seals also works much longer, even in the same conditions.

Total piston surface area between stock and most big brake kits is almost the same.

yep, but on multi piston calipers you'll apply force a lot more evenly on surface, especially on the large pads.

[Aus335iguy]

HI guys thought that id chime in.
Ive recently upgraded my 335i's brakes to the f3x m performance brakes as well as M3 e9x master cylinder. I have some relavent experience i can share to help people understand some of what might be happening here.

The coloured front callipers vary - there are two blue types ones suited to 340mm discs and others from the M3/4/m performance that are suited to 370mm and 380mm discs. They will have a number cast into them its either 340or 370/380. The red yellow and orange M performance brakes are all suited to 370/380mm discs and can be purchased brand new for around 1200 US from your local dealer or online. You will then need M4 discs and the whole lot will bolt up.

What im saying is that MDMA 135i probably has the 340mm set and needs a bracket to suit the larger 380mm discs. The callipers and discs from an M4 should bolt straight on to a e9x m3. It's the same calliper different casting.

The rears should bolt up as well, just use the m4 discs as doogee has said.

How do i know this? Ive been wrestling with a similar conversion myself on my 335i.

For those saying things like get a proper upgrade buy a BBK etc .... this isnt an upgrade. Thanks for your input, perhaps comment on the threads about your experience with your brake kit. You've stated you dont think its a good idea... thanks. That's all we need. If this isnt a worthwhile upgrade people will post negative experiences and eventually the thread will die. But if you haven't tried it yourself maybe leave the commenting to those that have?

MDMA 135i and doogee id appreciate some pictures of your rear calliper setups with e9x and f8x discs to compare...

[slonik]

The callipers and discs from an M4 should bolt straight on to a e9x

they shouldn't.
m3 e9x/1m e8x has 138mm between caliper lug mount bolts, e9x/e8x non M has 122mm between bolts, same size as on f3x and f8x.

f3x has fully the same lug mounts as on e9x e8x non M, cause you can take 370mm rotor from f3x and fit it with same for 4 pot.

but! 4 pot caliper on f8x works on 380mm rotor with different height (from memory 62.3 vs 73mm on non M), so lug mounts has the same size between bolts but all other dimensions differs from non M upright.

and, 340 and 370mm rotors are shit, compared to 360/380 M rotors, because M rotors has floating construction (non M are two piece but fixed).

[Aus335iguy]

Well Im wrong about the fronts then. The rest still holds true ?

[MDMA 135i]

Rear m4 brake rotors and calipers bolt on 1m, e92 m3.

I made bracket for front on cnc. i will install it after new year. If you are interested we can make group by for about 250$ for front bracket.