BRAKE ISSUE WITH 135i CALIPERS

[WarrenRB]

We witnessed the same issue (over heat) on EVO 8/9 community, enthusiasts suggested similar type fixes; add cooling ducts, bend/trim dust shield etc. But those expected cooling improvement are limited and can hardly solve the fundamental cause (lack of cooling air be correctly circulated into the heat exchanger - rotor).

EVO racers suffered this same issue were advised to remove all these auxiliary devices, (also remove the dust shield), and install RB two piece rotors and the problem went away. You can verify this from EvolutionM forum here.

RB's hat is connected to disc via the center-mount tabs alternatively from both sides of disc (vs. traditional surface mount which has no air admission from outboard) which provide wide open air ports from dust shield side (IB) and wheel side (IB) - Other brake company offers directional hats trying to achieve the same purpose, however the air doesn't travel in angle, and those slits are to easy to clog up.



Don't forget the air (gap) is the best natural insulator, so if you have a clearance of 6-8mm (from rotor surface to lower ball joint which is usually available unless you install a BBK that pushes the rotor further in) you shouldn't be concerned of over heating the ball joint. Or you can warp it up with some blanket insulator as an extra precaution.

The idea is to ultimately keep the heat out of the rotor by allowing more cooling air to come in (uniformly from both sides, instead of just blowing from IB via cooling duct) and remove the heat out of the rotor as quickly and as efficiently as possible.

RB's convergent vane design is another proven feature that allows the cooling air to stay in the vanes longer (vs. conventional curved vane) for a more efficient heat dissipation for a more uniform temperature across the disc (inner to outer edge, inboard to outborad).



Heat removal = Air flow x (T2-T1)

T1= Air temp @ entry (inner edge)
T2= Air temp @ exit (outer edge)

[pixelblue]

^ I don't see the purpose of this post since you don't offer a solution for our cars. Or do you?

[Focusedintntions]

They're working on something I believe Kori..

[WarrenRB]

Originally Posted by pixelblue

^ I don't see the purpose of this post since you don't offer a solution for our cars. Or do you?

I think it's good that we learn these fundamental, understand where the problem comes from before we can come up for a solution.

This is what I just posted in the other thread:
http://www.1addicts.com/forums/showp...7&postcount=19

Understand that most cars are made for street driving although some makes or models are more "motorsports" built but literally no stock cars are made for all level of track racing, therefore if you are more on intensive track activity M series is more for that purpose with less modifications/improvement than 135i.

Stock brake (rotor size more specifically) set up is usually how we judge the purpose of the car is made for, not the caliper. As an example comparing to M series (E36, E46 to E90), although they come with floating type cast iron calipers, but they are strong and stiff and can perform better than some of the Big Brake Kits out there.

135i although has "6 piston" caliper but the pistons are made of Phenolic Plastic, light weight and good heat insulation, cheaper to make, but is brittle and fragile under stress load comparing to metal (iron or steel).

RB claims itself as a brake solution provider, so if there truly is a problem that needs to be resolved, then we will.

We have proven this in NSX, RX7, Z06, CTS-V, CamoroSS, G37S, and S2000... here I am talking about an affordable upgrade (not expensive BBK stuff) but for now we will let the consensus emerge then we can go from there.

[Xaeryan]

Originally Posted by rb4-bmw

We have proven this in NSX, RX7, Z06, CTS-V, CamoroSS, G37S, and S2000... here I am talking about an affordable upgrade (not expensive BBK stuff) but for now we will let the consensus emerge then we can go from there.

^ That, in particular, is what I'm interested in. Keep us updated with product/solution status.

[pixelblue]

Can you tell us when we may see your product available for our cars?

[WarrenRB]

This is how we proposed:
http://forums.racingbrake.com/showpo...2&postcount=12

[pixelblue]

Can we get this in plain English? Will this be a custom order or do you need a number of people placing orders first? 16 weeks to deliver? So we would be looking to next years track season before we can use them

[KNS Brakes]

Originally Posted by BMWbab1

It sounds like a lot of you are having serious problems with the 135i brakes. I too have been having a ton of problems which I think are all related to the lack of cooling/airflow to the brakes. Anyway, after a weekend at VIR and running HT-10 pads for the first time I noticed that the dust boots/seals around the brake pistons were starting to crack. First of all do I need to replace them or will the brake be ok without them. Second, is there an easy way to replace these if so where can I order the boots/seals or do I have to do a caliper rebuild? I really appreciate any help you can give me on this subject as the only reason I bought this car was to attend a few DE's a year and as of right now it looks like I might not be able to continue with these events due to the brake issues! P.S. I will be adding ducting to the brakes if I make it to another event.

Brian

Take a picture and take it to your dealer. "I went to a driving school similar to that which BMW puts on at VIR" (They were unloading a zillion of them after you all left the last time out there)

Rotor efficiency is not the answer to cooler pads/calipers. 2 piece rotors can last longer and may block some heat from the hubs/bearings. I still have high pad wear and my calipers look horrid. (C5Z06)

And shims may help the piston/boot - but the pads and rotors will get hotter. The heat has to go somewhere.

You can get some improvement from 2 piece rotors - we have been there/done that on STi's - but if a brake component is currently wearing fast due to heat i.e. piston crowns cracking in a few events or rotors cracking fast or high pad wear or whatever - more efficient rotors are unlikely to solve it. They MIGHT help a bit - again what we have seen is better ROTOR life and I expect that is due to both improved materials and better efficiency. (A completely new topic)

That suggests that this is a design flaw and BMW is likely pretty livid w/ Brembo. There simple yet damn good brakes are a hallmark.

Who else uses Brembo ceramic crowned pistons? That is one thing I didn't research.
If not - BMW has the choice of - flipping off a few race guys/track guys versus replacing a zillion expensive calipers (on street cars that likely have no risk but ....they read this thread!).

Pretty piss poor by Brembo btw - that name is plastered on the STi brakes as well and while Subaru didn't go for the ceramic topped pistons the STi calipers are far from a race caliper.

In STi land if they track a lot I tell them - sell the Brembo's to a WRX guy while the gold paint is still nice and glossy. Once you track it they lose half the value.

Brian is pretty fast on street tires and he told me his piston crowns are not looking good so that should help out the data pool here.

Brembo makes a competitive race product - but the OEM stuff seems to be lacking.

STi/EVO - terrible noise issues w/ any sort of moderately aggressive pad. Subaru changed the knuckle/bolting arrangement in both 05 and 06 to try and help it.

Camaro - same - enough fro GM to add giant ROLLER SKATES to the pads - hilarious

Older CTS-V/Mustang - no info - but uses the same pad shape as STi/EVO.

Newer CTS-V/GTR - this is the new 'Brembo' caliper - no real info yet but the multi depth pad shapes gets to be a pia. And enough w/ the damn drilled rotors...really?

If the Stoptech ST60 pistons fit right then it's probably the way to go for most. I did email ST - they are going to make the 1-series piston. I am not sure what the diff is between that and the ST60 pistons. Timing not available.

-Ken

[BMWbab1]

Thanks Ken for the info. I am going to inform the dealer and see what they say. BTW to all the track guys out there.....Ken is one of the most knowledgeable guys I have met when it comes to brakes and his prices are very reasonable. If you need any info on brakes or need to order some track pads I would highly recommend him! Give KNS Brakes a call and ask for him.

[davo135i]

mmm

[tro-nik]

Originally Posted by rb4-bmw

We witnessed the same issue (over heat) on EVO 8/9 community, enthusiasts suggested similar type fixes; add cooling ducts, bend/trim dust shield etc. But those expected cooling improvement are limited and can hardly solve the fundamental cause (lack of cooling air be correctly circulated into the heat exchanger - rotor).

EVO racers suffered this same issue were advised to remove all these auxiliary devices, (also remove the dust shield), and install RB two piece rotors and the problem went away. You can verify this from EvolutionM forum here.

RB's hat is connected to disc via the center-mount tabs alternatively from both sides of disc (vs. traditional surface mount which has no air admission from outboard) which provide wide open air ports from dust shield side (IB) and wheel side (IB) - Other brake company offers directional hats trying to achieve the same purpose, however the air doesn't travel in angle, and those slits are to easy to clog up.



Don't forget the air (gap) is the best natural insulator, so if you have a clearance of 6-8mm (from rotor surface to lower ball joint which is usually available unless you install a BBK that pushes the rotor further in) you shouldn't be concerned of over heating the ball joint. Or you can warp it up with some blanket insulator as an extra precaution.

The idea is to ultimately keep the heat out of the rotor by allowing more cooling air to come in (uniformly from both sides, instead of just blowing from IB via cooling duct) and remove the heat out of the rotor as quickly and as efficiently as possible.

RB's convergent vane design is another proven feature that allows the cooling air to stay in the vanes longer (vs. conventional curved vane) for a more efficient heat dissipation for a more uniform temperature across the disc (inner to outer edge, inboard to outborad).



Heat removal = Air flow x (T2-T1)

T1= Air temp @ entry (inner edge)
T2= Air temp @ exit (outer edge)

M brake discs are made of exactly the same principle

[Derek8819]

^^ Are those the BMW Perf ones for the 135 or the OEM 1M ones?

[Focusedintntions]

Those are M3 rotors Derek.....check out this thread for more info on it

http://www.1addicts.com/forums/showthread.php?t=639905

[wantm135i]

shiny and clean

[John O]

My MINI came with 6 pot Brembos which I've heard are the same as the ones on the 135 and 1M. After 4 track days on OEM pads, I experienced very uneven pad wear. Trailing edge down to backing plate while midpoint wear sensor was barely making contact with rotor. Pads and rotors were replaced by dealer so I didn't get to look at pistons.

[scottn2retro]

Hi All - early next week I'll be taking the following wheels to Warren at RacingBrake in Fullerton so he can do some measurements for max size brake kits:

- 2008 OEM 135i front wheel

- 2008 OEM 135i rear wheel

- Apex 18x9.5 et62 rear wheel (to fit 275/35x18 tires in the rear)

- Apex 18x9.5 et22 (to fit 275/35x18 tires with 1M front fender conversion)

[scottn2retro]

Hi All -

I visited RacingBrake in Fullerton. They gave me a tour of their shop and I was able to see first hand the quality of the materials and get a better understanding of the key elements of the rotor design.

So for the 135i race car, we're going to go with a 380mm rotor and 4-pot kit to fit under our 18x9.5" Apex wheels

[sour97]

how about this?

[carbonem3]

I switched to Stoptech Trophy Kit. I also bent the dust shields to "scoop up" more air. Now I traded the car and dealer said he would take the BBK off for me. But It appears that one of the mounting "carriers" is missing. BMW does not provide a part number so does not sell it without buying the caliper! DIX! Does anyone have one to sell or lend me? I need this ASAP as the dealer is getting very aggressive! I do not want to lose my BBK!
Please help!
thanks!!!!!!

[BMWbab1]

Go to machine shop and have one fabricated. It's a simple part to make for a machine shop.

[Dynamic1]

My 08 135i is at 92k miles and the rotors and pads were done (although the sensor still hadn't gone off)... so I took a look at my calipers and everything was in order. I'm all about some spirited driving (3 years in Germany to boot), and I'm surprised the original pads and rotors lasted this long. Sorry I didn't get more/better pics.