BMW Performance Brembo 6-Piston BBK from the 135i

[su45]

Does anyone have experience with the BMW Performance Brembo 6-piston BBK from the 135i? Seems too good to be true, the ECS kit is about 1/3 the cost of a standard 6-piston Brembo BBK. Any fitment issues, etc?


http://https://www.ecstuning.com/b-a...341136462akt1/

[Inizes]

They fit I guess. Their pistons apparently have heat issues because they’re ceramics. Start getting too much heat and they start to crack. Probably fine for street use, after all they were stock on street cars

[Obioban]

Yeah, those calipers are junk-- pistons crack when they get hot and the seals melt. For bling only, and they're also kind of ugly... so not great at that.

[terra]

Yeah, those calipers are junk-- pistons crack when they get hot and the seals melt. For bling only, and they're also kind of ugly... so not great at that.

I have heard (though have no real source to confirm) that the BMW performance version of those calipers have better pistons/seals than the less ugly 135i version that is otherwise identical.

Removing the vibration dampers also helps their looks

[maupineda]

Does anyone have experience with the BMW Performance Brembo 6-piston BBK from the 135i? Seems too good to be true, the ECS kit is about 1/3 the cost of a standard 6-piston Brembo BBK. Any fitment issues, etc?


http://https://www.ecstuning.com/b-a...341136462akt1/

I have them in my Z4M which comes stock with the same brake setup to the ZCP/CSL variants. you need brackets for perfect fitment and sweep of the OE 345x28 rotor. Reboot Engineering does versions for both, the 345 rotors and the smaller for the regular M3. you have the choice. I know that you can also add shims and get away with the 135i brackets if you have the 345 disc.

[maupineda]

Yeah, those calipers are junk-- pistons crack when they get hot and the seals melt. For bling only, and they're also kind of ugly... so not great at that.

Appearance is subjective, I find them more attractive than the Porsche Brembos that tend to look rather small. Also I won't say they are junk, many users in EU had no issues, and for track abuse, well, even the OE system falls short. depends of what you want of them.

[Obioban]

Appearance is subjective, I find them more attractive than the Porsche Brembos that tend to look rather small. Also I won't say they are junk, many users in EU had no issues, and for track abuse, well, even the OE system falls short. depends of what you want of them.

I would say these are a performance downgrade from stock. And with zcp/csl/z4m rears, bias is terrible.

[liam821]

You can buy new pistons from StopTech to correct the problems with cracking, but it will cost another $400.

https://www.turnermotorsport.com/p-3...-135i/?pdk=AQI

Unless you get a really good deal on the calipers, there are better options out there IMHO. By the time you add in the rotors, adapters, new pistons, and the actual BMW calipers, you could have just bought a set of StopTechs. Personally, I think using the Aston Martin calipers is a better deal - they're basically 4-pot Brembo GT calipers and you can buy them for under $400 a side brand new. The Porsche 911 calipers are another great option, although I don't think they look quite as good - but that's only if you care about such things. Porsche calipers are easy to find on eBay and very affordable.

My car with Aston calipers, 345 OE ZCP rotors, and Vagbremtechnic adapters. Perhaps one of these days I'll change the Aston logo to Brembo but meh.

[maupineda]

I would say these are a performance downgrade from stock. And with zcp/csl/z4m rears, bias is terrible.

You know, this is something I have always found interesting, I get the heat issues on track use with the 6-pots, plenty of evidence, now would you care expanding on the terrible bias? I have used the online calculator and comparing the numbers I actually was surprised that...

Assuming ZCP/CSL setup here

Front Clamping force: OE > 6-Pot > Porsche (so the 6-Pot are less of a downgrade compared to the Porsches in this regard)

Keeping the rears unchanged you made the bias more rearward with the Porsche's vs the 6-Pot as the reduction in clamping force is greater with the Porsches, unless I am not using the spreadsheet correctly. I am happy to be corrected so I can learn what I am missing. like for like Porsche would be worse for bias VS 6-Pot with a ZCP/CSL rear!

If you change the rears...

Rear Clamping Force: OE > Porsche

So yes, the vias would be better with the Porsche "upgrade" as a change in clamping force is perhaps more balanced front and rear, but the 6-Pot have more power up front vs Porsches, where you wanted for a front-engined vehicle, so I never understood why the Porsche option is prised as the go-to budget BBK, yet everyone bashes on the 6-Pot, which for street use are more than adequate. Like for like, both setups reduce brake power vs OE ZCP

[Obioban]

You know, this is something I have always found interesting, I get the heat issues on track use with the 6-pots, plenty of evidence, now would you care expanding on the terrible bias? I have used the online calculator and comparing the numbers I actually was surprised that...

Assuming ZCP/CSL setup here

Front Clamping force: OE > 6-Pot > Porsche (so the 6-Pot are less of a downgrade compared to the Porsches in this regard)

Keeping the rears unchanged you made the bias more rearward with the Porsche's vs the 6-Pot as the reduction in clamping force is greater with the Porsches, unless I am not using the spreadsheet correctly. I am happy to be corrected so I can learn what I am missing. like for like Porsche would be worse for bias VS 6-Pot with a ZCP/CSL rear!

If you change the rears...

Rear Clamping Force: OE > Porsche

So yes, the vias would be better with the Porsche "upgrade" as a change in clamping force is perhaps more balanced front and rear, but the 6-Pot have more power up front vs Porsches, where you wanted for a front-engined vehicle, so I never understood why the Porsche option is prised as the go-to budget BBK, yet everyone bashes on the 6-Pot, which for street use are more than adequate. Like for like, both setups reduce brake power vs OE ZCP

The goal of upgrading the brakes is to improve heat capacity, increase pad sizes, improve pad wear rates, and rigidly mount the calipers. There's no reason to increase the clamping force-- the stock calipers can already lock up the wheels with 285 wide slicks.

The best performance exists if you match stock brake bias and piston volumes. DSC is also the happiest with that (important even when DSC is off for ABS brake force distribution-- and the brake force distribution is why the e46 M3 is so good at stopping (and why porsche race cars often retrofit e46 MK60 DSC units). The best pedal feel exists when pedal volumes are at/near stock.

The Porsche option nicely matches the stock bias and volumes, so the DSC module is happy with it, optimize your braking. The volumes are also very close to stock, making the pedal feel is as good as can be. The 135i calipers get you close to stock ZCP/CSL bias with stock M3 rear brakes, but are way off with the ZCP/CSL rear brakes... and the volumes are off in the reverse scenario. So, you have to either compromise on volumes (feel) or bias (performance), and either way you have a crappy (failure prone) and ugly caliper.

[Tbonem3]

Ugliest calipers ever lol
DB9 fronts are super sexy
Meganes are pretty sexy
996 fronts are kinda blocky/chunky
996 rears are perfect looking

[maupineda]

thanks for bringing that chart up!!

Stock ZCP F&R: 58.0 / 42.0
Porsche F&R: 58.1 / 41.9
6-Pot F / Porsche R: 59.2 / 40.8 (this is my setup)

based on the above I struggle to see how much greater the Porsche F&R would be for me (1.1% difference)

Taking the piston heat issues aside for a moment I think we are splitting hairs for a street setup, and the clamping force is still better on the 6-pot.

Also, using the actual calculator the numbers vary slightly to what you see on the chart. but again, the difference is very minimal, so if you match rears and fronts accordingly, either setup can work great depending on the end-use.

I went with the 6-pot because I already had a brand new calliper I had bought years ago for another project I never completed, so I just had to source one calliper, and the brackets are needed regardless of what option you go with. In fact, with the 6-pot option, you can get away with just shims and save the brackets if you have the CSL rotor already. again, I went back and forth a lot on this countless times and in my case, the 6-pot was cheaper and saw no downside vs the Porsche setup for what I wanted, ultimately I wanted improved pedal feel and modulation. My setup is now on par with my ex Mustang with Brembo 6-pots, firm and modulable; and in the street, I cannot make them fade, but neither did with the OE setup, but the feel is miles better!!!

So saying they are junk I think is a stretch

[SeanE46]

E31 front 996 rear! I still have mine and refuse to sell them even after selling my E46.

[Obioban]

thanks for bringing that chart up!!

Stock ZCP F&R: 58.0 / 42.0
Porsche F&R: 58.1 / 41.9
6-Pot F / Porsche R: 59.2 / 40.8 (this is my setup)

based on the above I struggle to see how much greater the Porsche F&R would be for me (1.1% difference)

Taking the piston heat issues aside for a moment I think we are splitting hairs for a street setup, and the clamping force is still better on the 6-pot.

Also, using the actual calculator the numbers vary slightly to what you see on the chart. but again, the difference is very minimal, so if you match rears and fronts accordingly, either setup can work great depending on the end-use.

I went with the 6-pot because I already had a brand new calliper I had bought years ago for another project I never completed, so I just had to source one calliper, and the brackets are needed regardless of what option you go with. In fact, with the 6-pot option, you can get away with just shims and save the brackets if you have the CSL rotor already. again, I went back and forth a lot on this countless times and in my case, the 6-pot was cheaper and saw no downside vs the Porsche setup for what I wanted, ultimately I wanted improved pedal feel and modulation. My setup is now on par with my ex Mustang with Brembo 6-pots, firm and modulable; and in the street, I cannot make them fade, but neither did with the OE setup, but the feel is miles better!!!

So saying they are junk I think is a stretch

Didn't realize you had the Porsche rears-- that is certainly a better setup than either of the stock rear options.

That said...

For the street, you might as well stay stock-- you're not gaining anything with any BBK. If you have more clamping force (I haven't looked), I'd see that as a downgrade-- the stock clamping force is set as it is to optimize pedal feel and modulation. More isn't better.

For the bling, the 135i calipers are ugly.

For the track, the 135i calipers can't take the heat.

[maupineda]

Didn't realize you had the Porsche rears-- that is certainly a better setup than either of the stock rear options.

That said...

For the street, you might as well stay stock-- you're not gaining anything with any BBK. If you have more clamping force (I haven't looked), I'd see that as a downgrade-- the stock clamping force is set as it is to optimize pedal feel and modulation. More isn't better.

For the bling, the 135i calipers are ugly.

For the track, the 135i calipers can't take the heat.

Partially agree about staying stock, I needed to service my callipers, and I did not like the feel of the OE setup, and I was ready to make my car look a bit nicer and I personally like the 6-pots (I could afford a change to a Porsche setup just for that reason if I found them more handsome).

After my BBK journey, I did tell myself I may have just done brass bushings, better pads, lines, etc. but what is the fun in that ...

Back to the OP, my advice is to do your homework, look at the data, and call it a day based on what makes sense for you. all we can do is provide our experience and point of view. he asked about fitment, well these fit. sorry about the rabbit hole