[n55PR]

Anyone have experience with these? I find very little info on the Stillen AP Racing BBK, I do hear AP is market leader in brakes....but can't find any comments on people running these on e9x.

[DallasBoosted]

I think they're both very good products, I went with stoptech due to availability of 20 different kinds of pads, replacement rotors, and other parts. AP is a little more rare so you'll end up getting bent over by 2 or 3 vendors that carry their stuff.

[mashimarho]

I love my Stoptech.

[n55PR]

Thanks for the feedback. Stoptechseems to be a safe bet. They have 2 products, their Trophy kit looks impressive. I wonder why do they use external dust boots that can't handle heat genereated at the track on their base product. AP kit seems bullet proof.

Good point on the pads and rotors, I am going to look into these some more.

[DallasBoosted]

Originally Posted by n55PR

Thanks for the feedback. Stoptechseems to be a safe bet. They have 2 products, their Trophy kit looks impressive. I wonder why do they use external dust boots that can't handle heat genereated at the track on their base product. AP kit seems bullet proof.

Good point on the pads and rotors, I am going to look into these some more.

I've never really heard of anybody melting the dust boots on ST60 calipers. Certainly not on a street car/track days etc.

[n55PR]

I have been shopping around for a BBK and 2 sets of Stoptech I have seen pictures of have the dust seals cracked. I consulted with an experienced shop and I was told that it is common on ST, but not a big deal since these are secondary seals. I am by no means an expert, far from it, just info that has come my way.

[n55PR]

So, on the original question. I have been gathering information on ST and AP BBKs. As far as I can tell both kits are from reputable companies, and both are quality products. Parts and repairs are available for both. ST is much more popular, and has glossy paint. One area that I want to understand better is the design of the bbk for our cars, I have become curious since reading the ST white papers on brake bias and "balance". Marketing info IS aimed to a broad audience.

I enjoy tracking my car, and the fucntional aspect is most important to me. What really intrigues me is which kit has the best design specifically for our cars?, which company did their engineering work? Which kit is best designed for track use? Our cars are front brake biased as all general consumer road cars, which kit does a better job to optimize bias?

Stoptech claims they do this, that say they "improve on the OEM brake bias" tyically by moving it back 15-20%. I was able to validate this claim doing some basic math to come up with total caliper piston surface area. However, the real question is whether the design of the caliper change actually do anything to affect brake bias. I understand our cars have electronic proportion valves, so I would think the caliper piston sizing will not do anything to affect brake bias. A BBK will only help in managing heat using a more efficient caliper design, larger/better designed rotors, better materials, etc.

I know I am over simplifying and have limited knowledge on this complex brake stuff, but it seems ST brake bias and balance system claims may not apply to our e90s.

[Alpina_B3_Lux]

A good friend of mine - E92Fan over at the UK section - has been running the AP BBK for a few years and is very satisfied with it. IIRC he upgraded it with PFC discs and uses track pads when going on a circuit. Another friend of mine uses the same kit and is also very happy with it; generally speaking AP has an excellent reputation in Europe and the UK and is also not the most expensive solution.

StopTech is used among others by Alpina on their B3 GT3, and pursuant to reviews of this car the brakes are quite good (the magazine sport auto tested this extensively it appears).

Personally I'm running a Performance Friction BBK which is IMO the most technically advanced of them (but also among the most expensive) due to its monobloc design and one-pad-per-piston feature.

Alpina_B3_Lux

[n55PR]

the PFC BBK looks amazing, but pricey! Did you notice any increase in pedal travel?

[Alpina_B3_Lux]

Originally Posted by n55PR

the PFC BBK looks amazing, but pricey! Did you notice any increase in pedal travel?

No, there isn't any. Brakes just like stock, just more consistently and more precisely, and obviously without any fading in spite of abuse.

Alpina_B3_Lux

[IN54NITY]

Alpina_B3_Lux, I have a question for you. I have narrowed my choices of a BBK down to the ST 60s and the PFCs (from www.bimmerworld.com/ - fortunately I can get a good deal.) The PFC BBK (ZR31) for the 335 have 355mm rotors in the front and 371mm (not a typo, that ~is~ 37.1 cm) in the back. Do you also have the rear BBKs from PFC? If so, by chance do you know if they fit BMW style 189 wheels (18" x 8.5" ET 37)? This is a consideration for me in my decision - to swap calipers for summer and for winter (at least for the rear axle) as my car is used year around.

Edit: I would like to note that brake bias can be changed by using different pad compounds front to back, i.e. using Pagid Yellows in front, Pagid Orange in back, or PFC 06 vs PFC 01 vs PFC 08 etc.

[n55PR]

Originally Posted by aleckzandr

Edit: I would like to note that brake bias can be changed by using different pad compounds front to back, i.e. using Pagid Yellows in front, Pagid Orange in back, or PFC 06 vs PFC 01 vs PFC 08 etc.

I am considering trying PFC-08 in the front and PFC-01 in the rear on the stock brakes. If this doesn't work for me, then I will get the front ST bbk. It is pretty clear a rear bbk is not necessary.

Would the 08/01 combo do anything to move bias towards the rear? Anyone tried this?

[vasillalov]

Forge Motorsport recently released BBK for E9X platform. It's worth checking out, especially at those competitive prices.

[Alpina_B3_Lux]

Originally Posted by aleckzandr

Alpina_B3_Lux, I have a question for you. I have narrowed my choices of a BBK down to the ST 60s and the PFCs (from www.bimmerworld.com/ - fortunately I can get a good deal.) The PFC BBK (ZR31) for the 335 have 355mm rotors in the front and 371mm (not a typo, that ~is~ 37.1 cm) in the back. Do you also have the rear BBKs from PFC? If so, by chance do you know if they fit BMW style 189 wheels (18" x 8.5" ET 37)? This is a consideration for me in my decision - to swap calipers for summer and for winter (at least for the rear axle) as my car is used year around.

Yes, I have the complete PFC BBK, front and rear (I wouldn't do it otherwise either, otherwise the brake balance will be out of whack). The rear discs are larger because PFC includes the OEM style hand brake in it which takes up some space. I would think that they would also fit 18" wheels, as I know of several people who have installed 18" wheels onto this BBK. In order to be sure I would drop them an e-mail though and enquire, alongside with the dimensions of the wheel you want to use.

Alpina_B3_Lux

[vasillalov]

Waiiitt a second...

PFC makes a BBK for our cars? Where can I look at the specs/prices? On their web site all I could see is pads.

[IN54NITY]

Originally Posted by vasillalov

Waiiitt a second...

PFC makes a BBK for our cars? Where can I look at the specs/prices? On their web site all I could see is pads.

Look again No prices, but specs are in their PDF docs. The model for our cars as I stated above is the ZR31. Call Bimmerworld.

Alpina_B3_Lux.... thanks for the reply.

[vasillalov]

Originally Posted by aleckzandr

Look again No prices, but specs are in their PDF docs. The model for our cars as I stated above is the ZR31. Call Bimmerworld.

Alpina_B3_Lux.... thanks for the reply.

OOOOH! That's a very very nice surprise! I'll call Bimmerworld on 26th. I need to know prices. I am also looking at the Forge BBK kit for next track season.

EDIT: Found it!

Prices: $4500.00 for front and $3400.00 for rear. Just as I suspected: OUTRAGEOUSLY expensive!

[ForgedDistributing]

You should be able to find a nice new set for less than or about $6000.

[IN54NITY]

Originally Posted by vasillalov

OOOOH! That's a very very nice surprise! I'll call Bimmerworld on 26th. I need to know prices. I am also looking at the Forge BBK kit for next track season.

EDIT: Found it!

Prices: $4500.00 for front and $3400.00 for rear. Just as I suspected: OUTRAGEOUSLY expensive!

The PFs are expensive. Try calling Bimmerworld, they may be able to do better over the phone. Fortunately I can get wholesale.

[gh0ly]

AP racing brakes are commonly used in all types of Motorsports in Europe.
There are only three manufacturers which can compete on bbk market -
Alcon
APracing
Brembo

I was driving for a while Impreza STI with AP BBK and it was just perfect!