128i BMW Performance Brake Kit Questions and Discussion

[b1aze]

I picked up a set of front BMWPerformance calipers and rotors for a good deal and it made me start to consider what, if anything I should do with the rear calipers/rotors etc.

The RealOEM diagram ( https://www.realoem.com/bmw/enUS/sho...diagId=03_0118 ) doesn't spec out a rear rotor anymore however the caliper part number is slightly different than the OEM 128i PN ( 34216768697 / 698 for BMWPerf rears 34216768693 / 694 for OEM 128i rears). The rear calipers are the same as many of the E9X platform and some F3X platform cars, so sourcing used calipers to clean up and paint should be easy.

The pad part numbers are interchangeable ( 34216790761 ).

The hangup right now for me is deciding what is required for a rotor. The stock rotor is a 300 x 20 mm 34216855005 but the rotor used on the E9X "BMW Performance" style caliper is 34216855007 (Still 300 x 20).

Is there a way to find out the exact differences between the 2 rotors and if they are specified the same, I will likely just use the stock rear rotors but if they are NOT the same, I will have to decide what I want to do... if its worth buying and swapping additional calipers, rotors, pads etc.

[Suprgnat]

Originally Posted by b1aze

I picked up a set of front BMWPerformance calipers and rotors for a good deal and it made me start to consider what, if anything I should do with the rear calipers/rotors etc.

The RealOEM diagram ( https://www.realoem.com/bmw/enUS/sho...diagId=03_0118 ) doesn't spec out a rear rotor anymore however the caliper part number is slightly different than the OEM 128i PN ( 34216768697 / 698 for BMWPerf rears 34216768693 / 694 for OEM 128i rears). The rear calipers are the same as many of the E9X platform and some F3X platform cars, so sourcing used calipers to clean up and paint should be easy.

The pad part numbers are interchangeable ( 34216790761 ).

The hangup right now for me is deciding what is required for a rotor. The stock rotor is a 300 x 20 mm 34216855005 but the rotor used on the E9X "BMW Performance" style caliper is 34216855007 (Still 300 x 20).

Is there a way to find out the exact differences between the 2 rotors and if they are specified the same, I will likely just use the stock rear rotors but if they are NOT the same, I will have to decide what I want to do... if its worth buying and swapping additional calipers, rotors, pads etc.

The "hats" for the parking brake are 10mm deeper on the 1-series than on the 3. You can't use 3-series rotors unless you do the 3-series narrow hub mod.

[b1aze]

Originally Posted by Suprgnat

The "hats" for the parking brake are 10mm deeper on the 1-series than on the 3. You can't use 3-series rotors unless you do the 3-series narrow hub mod.

So can I simply expect my stock rear 300x20 rotors to fit just fine?

Edit: after digging a bit more, Based on the pictures from ECS, the rear rotors are PN 34216778051 which is equivalent to 34216855005 which is the stock rotor. Should bolt up just fine

[Suprgnat]

Originally Posted by b1aze

So can I simply expect my stock rear 300x20 rotors to fit just fine?

Edit: after digging a bit more, Based on the pictures from ECS, the rear rotors are PN 34216778051 which is equivalent to 34216855005 which is the stock rotor. Should bolt up just fine

Yes, the calipers are a bolt on reusing the stock rotors.

[justjohnny135i]

I have a set of StopTech sport slotted rotors, pads and sensors for the 128i I am trying to get rid of. I have a posting on the for sale section but I can give you more info if you are interested!

[MAMSport]

So I am in the process of replacing brakes on my 128i with the factory performance brake kit. I'll save the full details, but front brakes are same as 135i - 6 piston calipers, 2 pc drilled/slotted rotors, and pads. Rears are standard 300 mm x 20 mm, 128i rotors, calipers are larger piston, 328xi pieces (may be same as 328i?), and I have pads for 328i/xi which have multiple applications. I'm using Stop Tech drilled rotors on the rear, made specifically for ECS Tuning, same as the front 2 pc drilled/slotted rotors, and Red Stuff pads. So far, only fronts are done (one of the rear rotors was back ordered). Very pleased with brake bite and feel, have not done any bedding (will wait for rears and do it once) yet. Too early to determine the amount of dust.

[Thunderguts]

Originally Posted by MAMSport

So I am in the process of replacing brakes on my 128i with the factory performance brake kit. I'll save the full details, but front brakes are same as 135i - 6 piston calipers, 2 pc drilled/slotted rotors, and pads. Rears are standard 300 mm x 20 mm, 128i rotors, calipers are larger piston, 328xi pieces (may be same as 328i?), and I have pads for 328i/xi which have multiple applications. I'm using Stop Tech drilled rotors on the rear, made specifically for ECS Tuning, same as the front 2 pc drilled/slotted rotors, and Red Stuff pads. So far, only fronts are done (one of the rear rotors was back ordered). Very pleased with brake bite and feel, have not done any bedding (will wait for rears and do it once) yet. Too early to determine the amount of dust.

What are you using to code the performance brakes? Can they be done with Carly or Protool? I seem to remember someone saying that Protool has that option. I wonder what the coding even does. I would guess it either adjusts bias to account for the larger front calipers or adjusts the E-diff to account for the very slight change in the rear calipers.

[b1aze]

Originally Posted by Thunderguts

What are you using to code the performance brakes? Can they be done with Carly or Protool? I seem to remember someone saying that Protool has that option. I wonder what the coding even does. I would guess it either adjusts bias to account for the larger front calipers or adjusts the E-diff to account for the very slight change in the rear calipers.

I don’t plan on coding the new brakes.

[MAMSport]

My indy expressed concern that doing coding to the 'sport' brake setting might affect the tune. I'm looking for definitive information that the brake coding is not going to affect the tune. I recall reading that the sport setting will allow more fluid pressure before the ABS kicks in, I believe.

Corrections to the information I have would be welcome!

[Suprgnat]

Originally Posted by MAMSport

My indy expressed concern that doing coding to the 'sport' brake setting might affect the tune. I'm looking for definitive information that the brake coding is not going to affect the tune. I recall reading that the sport setting will allow more fluid pressure before the ABS kicks in, I believe.

Corrections to the information I have would be welcome!

I'm concerned that your indy was concerned that the sport brake setting would affect the tune. In any way.

[chris_flies]

Originally Posted by MAMSport

My indy expressed concern that doing coding to the 'sport' brake setting might affect the tune. I'm looking for definitive information that the brake coding is not going to affect the tune. I recall reading that the sport setting will allow more fluid pressure before the ABS kicks in, I believe.

Corrections to the information I have would be welcome!

I share suprgnat's concern. That won't change anything with the tune lol. I don't think it really changes anything TBH...

[MAMSport]

Thank you very much, Suprgnat and Chris! Does changing the setting really affect braking performance that I would notice?

[Suprgnat]

Originally Posted by MAMSport

Does changing the setting really affect braking performance that I would notice?

I did too many other brake coding changes at the same time to isolate any one thing.