[NedMorHP]

I've been modifying my 2018 M240i X-Drive I picked up a couple months ago and when I went to upgrade the rotors, I saw on a site that I can tell I have the M-sport brakes by the 2 piston caliper in the rear. The difference being 340mm vs 370mm?

My original window sticker says M-Sport brakes. I have Blue M calipers, SINGLE piston in rear, 2 piston up front.

Is there a M-Performance brake out there as opposed to the M-Sport I have?

I know I can just pull a wheel and measure, but I wanted to know if there are different packages I did not know about?, mm size, etc. as it may push me to consider a different brake set up altogether.

I just AutoX and occasional track day so I don't need massive brakes, but I'm going to be pushing 500-525hp to the wheels, so a brake upgrade at some level is prudent.

[freakystyly]

There's a piston on each side of the caliper.

M-performance do exist but are not blue, they came in red, yellow or orange with larger rotors.

[NedMorHP]

OK, Got it.

That's not how I am used to thinking about calipers. Two piston would be 2 opposing 'sets' of pistons. To operate the inside pad, there has to be an opposing piston.

So using that logic, the fronts are 4 piston calipers.

So the M-sport brakes are 370mm rotors.

[Kernel Kurtz]

No, the blue M-Sport calipers have the 340s. Lots of discussion of this in the chassis forum.

https://www.2addicts.com/forums/forumdisplay.php?f=522

[NedMorHP]

No wonder there so much confusion about this. Doing more digging, I found this:

https://www.bimmerworld.com/About-Us...-Brakes/#M235i

There's M-sport, then there's M-Sport S2NHA

base (M Sport) 340x30mm, blank
S2NHA M Sport/ZTR 370x30mm, blank

Maybe I should go back to my Porsche's.... :-)

[pikcachu]

Originally Posted by NedMorHP

OK, Got it.

That's not how I am used to thinking about calipers. Two piston would be 2 opposing 'sets' of pistons. To operate the inside pad, there has to be an opposing piston.

So using that logic, the fronts are 4 piston calipers.

So the M-sport brakes are 370mm rotors.

The right way of thinking is total amount of pistons per caliper.... any other thinking should be revisited

[freakystyly]

I think the 3 series has the bigger 370mm "M-sport Blue" brake rotors.. Just to add to the confusion.

[pikcachu]

Originally Posted by freakystyly

I think the 3 series has the bigger 370mm "M-sport Blue" brake rotors.. Just to add to the confusion.

Yes.... I've never seen a F22 with the bigger brakes that is not a M perf brake kit

[WolfGTI]

There are also adapters to allow you to keep the 340mm brake calipers but run the 370 / 380 mm rotors.

[NedMorHP]

Originally Posted by freakystyly

I think the 3 series has the bigger 370mm "M-sport Blue" brake rotors.. Just to add to the confusion.

That's what more digging revealed. From what I gather they could be swapped into the 2 series. But I'm not willing to go that far until there is a real issue after I put the slotted/drilled rotors, appropriate pads/fluid into play.

[NedMorHP]

Originally Posted by WolfGTI

There are also adapters to allow you to keep the 340mm brake calipers but run the 370 / 380 mm rotors.

This I have not seen, any links/names?

[seanroberts000]

If you're running 18" wheels, the 370mm rotors may be too tight.

Kern417 used to have the brackets available on F30/31 forums.

Learn from my mistake --
I recently replaced rotors/pads. I have the S2NHA option on my VIN sheet and blue rotors. Didn't pull off the wheel and measure, just ordered the 370mm from what I could see online. Was up on the lift with rotors detached, pads out, and everything apart before I decided to line up the new/old rotors. Thankfully Turner Motorsports didn't charge RMA shipping.

[dradernh]

Originally Posted by seanroberts000

If you're running 18" wheels, the 370mm rotors may be too tight.

Yes, the standard (old?) rule of thumb of rotor diameter + 4" says that at 18.57" an 18" wheel may be too tight for a 370mm rotor (and its caliper). However, and FWIW, as seen below the M Performance Brake Kit's 370mm front rotors fit with quite a bit of room to spare inside my OEM 436M 18" wheels. They also fit inside Apex ARC-8 18" wheels; I haven't measured the gap on those.

Bimmerworld asserts "massive caliper clearance" for its 17" TE:AL TA16 forged race wheel, leading me to wonder if that 17" wheel might possibly fit over the M Performance kit's calipers. Wouldn't that be something!

[NedMorHP]

Thanks for the link. I was planning on staying with the 18" rims, using the factory rims for winter, then in the spring going new rims/+2 tires.

Went autocrossing today and found out you CAN do a 4 wheel drift on a AWD car :-)

[NedMorHP]

Just a quick update, talked to Kern417. I ordered the adapters to run the 380mm rotors. He said they will fit the factory 18' wheels with a 5mm wheel spacer.

I may not do this till spring, I've only had the car for 2 months and I've already done the DP, Intake, TU pump, JB4 tune w/FSB, Meth injection, and xHP trans tune. I should have the Vargas GC turbo install done in the next day or two.

Not to mention the splitter, spoiler, diffuser, and other misc. mods.

I've been busy...

[flanmorrison]

I'm still figuring out the best route for my m235i, but this article gives a good explanation:
https://www.bimmerworld.com/About-Us...-Sport-Brakes/

[PaleoMan]

Hi,

I'm planning on replacing my front rotors and pads and had two questions...

Is it OK to reuse the caliper to wheel mounting bolts?

Does anyone know the torque setting for those bolts?

Thanks!

[ggggbmw]

Originally Posted by PaleoMan

Hi,
I'm planning on replacing my front rotors and pads and had two questions...
Is it OK to reuse the caliper to wheel mounting bolts?
Does anyone know the torque setting for those bolts?
Thanks!

The rear calipers are one-time use, as they have a torque-to-yield additional twist. However the fronts just have a straight torque rating. So, in theory, should be able to re-use.

Front caliper torque: 110 Nm

The bolts are fairly cheap though. ~$6 each. So I did replace them when I did mine.
M12x1.5x43 ZNS3 , 2/caliper, P# 34106864424

[PaleoMan]

Originally Posted by ggggbmw

The rear calipers are one-time use, as they have a torque-to-yield additional twist. However the fronts just have a straight torque rating. So, in theory, should be able to re-use.

Front caliper torque: 110 Nm

The bolts are fairly cheap though. ~$6 each. So I did replace them when I did mine.
M12x1.5x43 ZNS3 , 2/caliper, P# 34106864424

Thanks for the info! Any suggestions on sources where I can get the bolts?

[ggggbmw]

I bought them from FCP Euro:
https://www.fcpeuro.com/products/bmw...nt-34116772117

But this is the kind of small part where a dealer isn't outrageous especially after you consider shipping. And they are available at tons of other places online. Just google the part number.

[PaleoMan]

Thanks!