[Jadar]

Originally Posted by rlesko

Sorry for necro but...

Do you or anyone else know if a M235i caliper will fit on an F30?

Having trouble procuring the 2 piston rear brembos at a reasonable price.

Yes

[rlesko]

Originally Posted by Jadar

Yes

[rlesko]

Just bought some junkyard rear calipers from an m240i. This thread was amazingly helpful, so thanks again Jadar !! Will post a final pic once done installing.

[rlesko]

With regards to coding, is the appropriate move here to VO Code HO WORT SPBR or add 2NH SA option? or both?

[casualDIYer]

I'm thinking of the rear caliper upgrade as well for an LCI 340xi. But it seems there is a small difference in part numbers for the Brake Servo Unit. As per RealOEM,

For 340xi non-M brakes with rotors 340X30 Front + 330X20 Rear)
34336851095 - Master Cylinder
34336872636 - Brake Servo Unit

For the 240xi (with B58 6-cylinder engine)
Rotors are 340x30 Front + 345x24 Rear)
34336851095 - Master Cylinder (same as non-M 340i)
34336851098 - Brake Servo Unit (different part number)

For the 340xi M Brakes with rotors 370x30 Front + 345x20 Rear)
34337849878 - Master Cylinder (completely different to non-M & 240xi)
34337849876 - Brake Servo Unit (completely different to non-M & 240xi)

So, without the 370x30 rotors, one can use the same Master Cylinder but perhaps with the rear 345x24 rotors, the Brake Servo Unit needs to be swapped out to be the same as the 240xi? Is that even possible? Are the parts specific to a set of brakes or to a car?

[rlesko]

Originally Posted by casualDIYer

I'm thinking of the rear caliper upgrade as well for an LCI 340xi. But it seems there is a small difference in part numbers for the Brake Servo Unit. As per RealOEM,

For 340xi non-M brakes with rotors 340X30 Front + 330X20 Rear)
34336851095 - Master Cylinder
34336872636 - Brake Servo Unit

For the 240xi (with B58 6-cylinder engine)
Rotors are 340x30 Front + 345x24 Rear)
34336851095 - Master Cylinder (same as non-M 340i)
34336851098 - Brake Servo Unit (different part number)

For the 340xi M Brakes with rotors 370x30 Front + 345x20 Rear)
34337849878 - Master Cylinder (completely different to non-M & 240xi)
34337849876 - Brake Servo Unit (completely different to non-M & 240xi)

So, without the 370x30 rotors, one can use the same Master Cylinder but perhaps with the rear 345x24 rotors, the Brake Servo Unit needs to be swapped out to be the same as the 240xi? Is that even possible? Are the parts specific to a set of brakes or to a car?

That doesn't seem right. To my knowledge, the big brake kit doesn't ever include that part. See here. Furthermore the only requirement ever listed for the kits themselves are 18"+ BMW wheels.

Not sure what the differences in servos is, but doesn't make sense to read into it.

[casualDIYer]

Originally Posted by rlesko

Not sure what the differences in servos is, but doesn't make sense to read into it.

Given the servos are effectively brake boosters, it's a good question as to what the difference is in part numbers. A larger caliper would use more brake fluid. What component controls that? How does the car know exactly how much fluid to pump into the brake caliper?

[rlesko]

Originally Posted by casualDIYer

Given the servos are effectively brake boosters, it's a good question as to what the difference is in part numbers. A larger caliper would use more brake fluid. What component controls that? How does the car know exactly how much fluid to pump into the brake caliper?

I believe the coding lies within the DSC module. I am admittedly not an expert, but as long as the system has enough brake fluid and the brake bias is set properly, everything should work fine. Maybe a bigger master cylinder could probably provide more force to the pads, but its probably not necessary to even delve into such things for a daily driver.

[johnung]

Originally Posted by casualDIYer

I'm thinking of the rear caliper upgrade as well for an LCI 340xi. But it seems there is a small difference in part numbers for the Brake Servo Unit. As per RealOEM,

For 340xi non-M brakes with rotors 340X30 Front + 330X20 Rear)
34336851095 - Master Cylinder
34336872636 - Brake Servo Unit

For the 240xi (with B58 6-cylinder engine)
Rotors are 340x30 Front + 345x24 Rear)
34336851095 - Master Cylinder (same as non-M 340i)
34336851098 - Brake Servo Unit (different part number)

For the 340xi M Brakes with rotors 370x30 Front + 345x20 Rear)
34337849878 - Master Cylinder (completely different to non-M & 240xi)
34337849876 - Brake Servo Unit (completely different to non-M & 240xi)

So, without the 370x30 rotors, one can use the same Master Cylinder but perhaps with the rear 345x24 rotors, the Brake Servo Unit needs to be swapped out to be the same as the 240xi? Is that even possible? Are the parts specific to a set of brakes or to a car?

You are over thinking it. BMW makes the M Performance Brake Kit which is plug and play with all F3x models. That means that an F3x with the smallest brakes which are front single piston 312mm x 24mm and rear 300mm x 20mm can be upgraded all the way to the largest F3x brakes which are front 370mm x 30mm and rear 345mm x 24mm. To install this kit on any F3x car there is absolutely no change to the brake master cylinder or to the brake servo.

BMW includes a detailed list of instructions for the tech to follow. NOTHING concerns the master cylinder or the servo. The only caveats in those instructions do NOT apply to the 340i because it already has them, like the installation of larger brake dust shields, coding the front/rear brake bias which is the same for the 340’s stock F340/R330 setup and the F370/R345 setup, and installing rear rotors with the larger 185mm e-brake machined inside the rotor hats (which is just buying the correct rear rotor), and the 18” wheel size minimum to fit over the larger calipers

[casualDIYer]

Originally Posted by johnung

You are over thinking it. BMW makes the M Performance Brake Kit which is plug and play with all F3x models. That means that an F3x with the smallest brakes which are front single piston 312mm x 24mm and rear 300mm x 20mm can be upgraded all the way to the largest F3x brakes which are front 370mm x 30mm and rear 345mm x 24mm. To install this kit on any F3x car there is absolutely no change to the brake master cylinder or to the brake servo.

BMW includes a detailed list of instructions for the tech to follow. NOTHING concerns the master cylinder or the servo. The only caveats in those instructions do NOT apply to the 340i because it already has them, like the installation of larger brake dust shields, coding the front/rear brake bias which is the same for the 340’s stock F340/R330 setup and the F370/R345 setup, and installing rear rotors with the larger 185mm e-brake machined inside the rotor hats (which is just buying the correct rear rotor), and the 18” wheel size minimum to fit over the larger calipers

Still seems kind of curious why there are different part numbers. BMW phukery . . . .

[Uppal92]

Originally Posted by Jadar

I started looking into getting rid of the ugly Bosch rear calipers. I went in on a deal with peterparker , he needed the front and I took the rear. They were super cheap $1250 from eBay for yellow M performance kit.

Why did I do this? Well simple to save money $850 and the performance is 95% the same as having the 370mm up front for street use. Why waste a good 4 piston brembo caliper because it uses a slightly smaller rotor

It took me a while to find all the info, since not many go this route so I am confirming It does work! After much controversy I found out that the M235i runs this setup from the factory. 340mm front (blue) 345mm rear (blue).

You need rotors for the rear I ordered part #34206797607

1. Painted the front calipers Phoenix yellow code 455
*i used m performance cast sticker logo on front just to add a bit of uniqueness to it.
2. Install rears, use Motove bleeder to bleed the calipers.
3. CODE the rears to appropriate size under DSC
It's c_variante_bremsscheibe_hinten_c and change from 20/330 to 24/345.

If you don't, you may end up with some pedal moosh.
I did. But after coding it went away

It works! DSC works ABS works, Launch Control works as it should. No issues at all.

Tip: if you have a 35i series car do not swap out the dust shields, they're the same size in the m performance kit. And to boot I got the wrong ones designed for a 320i/328i hub.
Plus the hub needs to come off to instal the shield appropriately. SKIP this the 345mm rotor has no issue clearing a 335 shield.

Downside is I have the M [...]

Thanks for this as I just wanted to confirm if we can do this mod where I am planning to use unfinished/grey brembo callipers for the front, will get them sprayed blue and a M logo. For the rears I want to replace one piston with the brembo 2 piston blue callipers on 345 x 24mm rotors in my 328i. A quick question, what is the process of vo coding do I just have to code for the rear brakes as they are the only one to be replaced? Thanks in advance.

[rlesko]

Originally Posted by Uppal92

Thanks for this as I just wanted to confirm if we can do this mod where I am planning to use unfinished/grey brembo callipers for the front, will get them sprayed blue and a M logo. For the rears I want to replace one piston with the brembo 2 piston blue callipers on 345 x 24mm rotors in my 328i. A quick question, what is the process of vo coding do I just have to code for the rear brakes as they are the only one to be replaced? Thanks in advance.

I spent a great deal of time trying to research this and there seem to be two options. You either need to add SPBR to HO-WORT or add SA option 2NH.

In other thread, someone with 2NH compared CAFD files when adding SPBR and it seems there is no difference except the date https://f30.bimmerpost.com/forums/sh...8&postcount=16. The logical conclusion here is that 2NH is equal to adding SPBR or a superset of SPBR.

Putting on my BMW goggles for a moment, I suspect that depending on your integration level, your car may not understand what option 2NH is. This is purely speculation, so don't take it as a statement of fact. Just a guess on why BMW seemingly has two ways to do the same thing.

There are many youtube videos on how to add SPBR to your VO.

Changing individual rotor sizes via FDL coding likely has no effect.