[thielepr]

Would it be possible to mount the rotors from M2/3/4 into ours F22’s? Ours run 340mm and the M cars runs 380mm but same pads and calipers

[cooolone2]

Why not try it and let us know?

[dradernh]

Originally Posted by cooolone2

Why not try it and let us know?

My thinking is that a very good reason is that it can cost a large sum of money for an owner to discover that he or she has made a major mistake.

Having rolled down that road myself on numerous occasions, I would suggest that is a reason to "not try it".

-----------------------------

P.S. They're not going to fit. (As it turns out, they will fit; see further down for specifics.)

[dradernh]

Originally Posted by thielepr

Would it be possible to mount the rotors from M2/3/4 into ours F22’s? Ours run 340mm and the M cars runs 380mm but same pads and calipers

I recommend contacting Bimmerworld; they'll know what fits and what doesn't.

I think they'll suggest the kit below is your sole(?) larger-rotor option. It's got 370mm front rotors, no need for new rear rotors (although they're available if you want rear matching dimpled & slotted rotors), and a full set of calipers in a choice of colors. The calipers come loaded with a fresh set of pads.

https://www.bimmerworld.com/BMW-M-Pe...t-F22-F3X.html

Note that the kits are substantially cheaper at getbmwparts.com, which is a BMW dealer in Maryland:

Red - https://www.getbmwparts.com/oem-part...ed-34112450468
Orange - https://www.getbmwparts.com/oem-part...ge-34112450470
Yellow - https://www.getbmwparts.com/oem-part...ow-34112450469

The kits require 18" wheels and coding by the dealer. I have the orange kit and the 18" BMW wheels that came on my car fit over the calipers easily.

[BillG2A]

It is possible. Stock calipers , custom brackets, M3/4 retention screw and M3/4 380mm rotors

[jordan24c]

Originally Posted by BillG2A

It is possible. Stock calipers , custom brackets, M3/4 retention screw and M3/4 380mm rotors

These are the brackets from Kern, correct?

[BillG2A]

True

[dradernh]

Originally Posted by BillG2A

It is possible. Stock calipers, custom brackets, M3/4 retention screw and M3/4 380mm rotors

Originally Posted by jordan24c

These are the brackets from Kern, correct?

Good to know. I'd made the assumption that no one was selling brackets.

Do either of you have a link to the brackets or contact info for the vendor?

[BillG2A]

Here is the email for kern with the brackets for 340-380 mm conversion. Fronts brackets are $250. I put together front conversion for $780 with brackets , rotors and retainer screws for rotors.

Kern also makes a 370-380 mm conversion uses an offset bushing only , no bracket.

a different company , SeemsLigitGarage.com makes kits brackets for 370 mm to 380 mm conversion you may be interested in one of those two for your m performance calipers. I added a picture below

Bill

[grocerylist]

That's pretty awesome! I thought I'd previously read that this wasn't possible, glad to see someone made a bracket for them. I'm curious what the weight difference is between the stock aluminum hat 340mm discs vs the M3/M4 380mm discs.

[aerobod]

Originally Posted by grocerylist

That's pretty awesome! I thought I'd previously read that this wasn't possible, glad to see someone made a bracket for them. I'm curious what the weight difference is between the stock aluminum hat 340mm discs vs the M3/M4 380mm discs.

According to the weights on realoem.com, stock 340mm discs are 10.3kg each, F8x M3/4 discs are 11.3kg each.

[grocerylist]

I'm trying to figure out a reason that you wouldn't want to do this. Beyond the initial up front cost, long-term if you were buying rotors from FCP Euro, you'd only have return shipping costs of the rotors and new rotors would be free via their lifetime replacement guarantee.

I've always heard that the sport brakes were a weakness for the 2er. As far as track performance, would these be expected to significantly improve resistance to brake fade via larger cooling surface/vanes and the addition of a quality high performance brake fluid or are the calipers the weak point?

[thielepr]

Nice info guys. Really good information

[thielepr]

Any link for Kern adapters? I see the email there but wonder if there is a website

[dradernh]

Originally Posted by grocerylist

I'm trying to figure out a reason that you wouldn't want to do this. Beyond the initial up front cost, long-term if you were buying rotors from FCP Euro, you'd only have return shipping costs of the rotors and new rotors would be free via their lifetime replacement guarantee.

I've always heard that the sport brakes were a weakness for the 2er. As far as track performance, would these be expected to significantly improve resistance to brake fade via larger cooling surface/vanes and the addition of a quality high performance brake fluid or are the calipers the weak point?

The size and design of the 380mm rotors should make a significant difference in how quickly the braking system's components heat-up. My guess is that they're not so robust that the rest of the system's components can no longer be overheated. It seems to me that a driver braking too much on a high-speed, heavy-braking track will still be able to overheat every component in the system.

Our car's braking systems' weak point is the lack of an opening available to route air through the rotor centers and out past the vanes. That's how rotors are kept cool, and that leads to all of the downstream components staying within their respective temperature specifications (e.g., pads and fluid).

[jordan24c]

Originally Posted by thielepr

Any link for Kern adapters? I see the email there but wonder if there is a website

No, you'll have to email him and get on the waitlist as the demand has been super high since he rolled these out a few weeks ago. He's pretty active on his instagram as well as youtube; quick to respond to emails too.

[BillG2A]

Tested the M2/3/4 brakes at Road Atlanta last Friday
15 stops at turn 10AB from 130-135 mph No Fade nor excessive heat issues Ran Hawk dct 70 pads Motul 660 fluid

Great front BBK upgrade for $780

[cooolone2]

So, new bracket and rotors with an adapter that offsets the caliper mount to accommodate the rotor diameter. Are the pads for the new rotor, not stock (rotor) as well. I believe yes, just want confirmation!

And thank you for sharing and posting!

For the original response to my "try it" and let us know... I've been a modder for a very long time (other platform) and that's how it worked, how it's shown now here by @[BillG2A]

I wasn't being smart, just noting that many go through that trial an error to find the right moves and shakes for upgrades like this. BMW aside who seem to want to limit the sharing of information and specs that DIY would need.

Thanks again and thank you for posting!

[BillG2A]

So to be clear you asked if pads need to be changed ? The answer is no. You can use stock pads with this modification. No change required

They even fit under stock 18" wheels (you may have to use 5-10mm spacer) I had a 7 mm spacer already On car and have not tried to fit them without the spacer

Depending on the year M240. M2/M3/M4 used same caliper design with same pad design / shape/size. Pad material / friction were different

You may want this modification for looks and or performance. I did it for performance / factor of safety for track events So I use Hawk DCT 70. Great bite and release and no fade even with 340 mm but extra bite generated so much heat that calipers discolored and dust seals cracked at 26k miles after just a few events

So I was looking for a better heat sink which I got with 380 mm larger with there aluminum hats and they have a superior rotor vane design compared to the 340 mm to enable air to pass through them
Those pads have a down side 1) are more expensive than stock 2) heavy dust 3) are very very loud
I also run Motul 660 brake fluid which is ~$30 a bottle and requires more maintenance

I do not believe there would be any performance gains for street driving with rotors or pads , not even shorter stopping differences Probably better fade resistance if you drove mountains canyons

Life long enthusiast. I started with Mitsubishi Starion and drove all over us including One Lap of America / Cannonball Run event Owned 1st gen NSX , BMW E39 CTS-V., Golf Type R Modded all of them and only thought the CTS-V came with sufficient brakes for track events.

This F22 bracket solution Kern has developed is very well done and inexpensive. I found him on YouTube and he does not have a web site and there was a bit of a wait. He primarily focuses on B58 power for straight line performance The machining of brackets and quality of fasteners/bolts appears high
They are not highly finished like the 370 to 380 brackets that seemligit garage sells

[cooolone2]

Yes, thank you for your prompt reply. I was wondering if the pads for the larger rotors can be used then? Wouldn't they be slightly larger due to the increased diameter? Otherwise using the same pad naturally wouldn't increase stopping performance because the same surface area is applying friction. Heat dissipation aside.

I'm going to order these brackets, even though I won't need them for a while because I still haven't cracked 10k miles yet, lol. But unlike being prepared! . I've seen Kern's vids before as well. Good stuff!

And thinking about it too, with 10mm spacers, are longer wheel bolts needed/available? Is Grade-8 hardware needed?

Sorry for all the questions, appreciate your thoughts!

Cannon Ball Run!!! That's amazing and awesome!

My last toy E46, and before that my Pontiac L67 engine Grand Prix with a complete custom build, self built & tuned, still have it but is neglected now that I have the M240 . Always a Pontiac nuff from my first car, a 73' Grand Am and was hooked! Lol

TIA

[jb-slow]

Originally Posted by cooolone2

And thinking about it too, with 10mm spacers, are longer wheel bolts needed/available? Is Grade-8 hardware needed?

Do yourself a favor and do a stud conversion instead, it's the 1 thing american cars get right. No more balancing wheels while you're trying to line up holes, or having the wheel fall off when you miss.



I have both the front and rear brackets on the way. Already have the rotors here waiting for their arrival. Will post pics when it's all together.

[BillG2A]

I did stud conversion