[13749032]

Well I finally went almost to Poland to pick up my new BMW 313's, and I saw another 328i there with the Gold Brake Kit and was DROOLING.... Does anyone have this kit installed and is it worth the funds?

[jbass524]

This is my original review:

I think you have to ask yourself why you're buying the brakes: ease of pad change, better performance, cooler looks?

This is just my opinion from track experience with both the 335 brakes and the performance brakes both with stock pads. This was at Laguna Seca. I drove a 135 with the performance brakes for a day and I own a 335 which I've driven at Laguna twice before.

Performance Brakes (PBs) to 335 Brakes Comparison:

1. Neither brake are top loaders so pad changes are difficult
2. The PBs fade just like the 335 brakes with little difference. In fact I had never lost brakes in my 335 and I did in the 135 (into turn 11), 3 times.
3. Better pedal feel on PBs until they're gone
4. PBs look a little cooler

NET = no good reason to buy

If you're tracking your car and are using up the stock brakes get track pads and rotors or just track pads then bed them in. Use the high temp brake fluid of your choice.

Check this post for more information: http://www.e90post.com/forums/showthread.php?t=239528

[bavarian19]

I debated the same a while back. Might as well get 335 front brakes.

[FCP Euro]

Sounds like the PBs can be worse in some situations. Also, the 135 is a lighter car then the 335 so that is also something to look at.

[lcrain]

For the money I think you would be better off getting a stoptech kit, or brembos. Both are proven upgrades.

[13749032]

Thanks for all the feedback, Keep it coming as I am looking to purchase a brake kit (Mabey in the near future)......with funds permitting...

[stressdoc]

The 328 Perf kit looks pretty good for the $. For function on a new car, I would start with new pads and SS brake lines. When rotors and pads are worn, then I might opt for Perf kit, or a 335 front set. Not up to serious track duty.

[Anthony@F1 Autohaüs]

For the Price its not bad for what u get (Appearance Wise). If you are looking to performance wise. If you don't want to spend the money on a BBK but upgrade for Decent Price get the F1 Autohaus Performance Stage 2 Upgrade Kit (Stoptech).

-Anthony@F1 Autohaus

[E92Fan]

I made the post below in relation to a question a UK member posted, asking about the value of changing to the BMW BBK system and also why it was so cheap in comparison to the 'proper' BBKs like APs or Brembos. His car was a 325i, he liked to do a little track work, but mainly his car was used on motorways/highways for his work commute. Thus my response is European focussed, with UK pricing - however the principles of the post remains the same and I think it might be valuable here too.

Originally Posted by E92Fan

The BMW BBK system is undeniably good value - 6pot Brembo calipers at the front, 4pot rears, drilled discs, different pads. For the money, it's unbeatable

However, you have asked a very valid question as to why they are so cheap. The thing with 6pot brakes is that across the range there is a HUGE variation in quality and performance.



Firstly, it would be an idea to understand a little bit about the design of multiple-pot calipers and the advantages/disadvantages of certain systems.

Generally, and in the most simplistic view, the most important aspects of a brake caliper design are -

a) the technical suitability of the caliper force in relation to the target vehicle
b) how evenly it distributes braking force across the entire face of the pad,
c) the heat resistant capability of that caliper in terms of the way it can dissipate heat away from the pads,
d) the long-term durability and reliability of the caliper
e) weight


There is a common misconception that the greater number of pots the better the braking system. A bigger set, or a greater number, of caliper pistons will provide more clamping pressure on that axle, but could also have a negative effect on total brake performance. If the pistons are too large for the application it will lead to excessive pedal travel and the front/rear brake balance will be adversely affected, resulting in longer stopping distances. Clamping forces can also become so strong that you'll end up locking the brakes far too early, making brake modulation and control very difficult.

In reality, the number of pots is not as important as the technical design and setup of each caliper to a particular vehicle. In the most simplistic terms, the greater the number of pistons/pots, the greater the surface area of pressure being applied to a brake pad, and hence the greater amount of friction generated (assuming the brake pad characteristics haven't changed in the comparison). However, it is more important that the correct braking force is distributed along the pad - having a more efficient 4pot system valved correctly for the vehicle will give much better braking performance than an oversized 6pot caliper with mismatched valving.

A larger brake caliper normally leads to using larger-sized pads - however, just because a pad is larger doesn't mean that there is more braking force. A bigger pad of the same compound in the same location as a smaller pad will not actually give shorter stopping distances. The stopping force or torque reaction is derived from the pad friction coefficient, the diameter of the brake disc and the amount of pressure applied. A bigger pad does not apply more pressure, only the same pressure over a bigger area. The advantage of a bigger pad lies in its heat capacity and rate of wear - the larger the pad, the more it will be able to absorb initial heat, thus suffering less thermal shock and with the consequent advantage of greater pad life.

However, there are sometimes problems with having larger pads - the popular Porsche calipers use a taller pad than most other systems, and whilst this taller pad gives slightly better heat characteristics, the system actually requires a heavier brake disc to match. This heavier disc has greater inertia and if the piston valving pressure is not adapted to suit, you actually end up with longer braking distances.

Piston/caliper design is also important - the cheaper calipers generally use stainless steel or aluminium alloy pistons coupled with simple dust boots, and are almost always of a two-piece cast aluminium design. The most expensive calipers may use titanium pistons (lighter and stronger), with much better high-temperature dust seals on each piston. They may also be of a forged monobloc design, which if designed using the correct alloys may well be stronger than a regular caliper, but may not necessarily be stiffer. A big brake kit will provide increased heat capacity, which means substantially more resistance to brake fade and caliper distortion with multiple stops from high speed. The stronger the caliper, the less the distortion and the more precise the braking performance. It will also give a firmer pedal due to stronger and stiffer components, as well as better modulation characteristics. The lighter the caliper the greater the reduction in unsprung weight, which will yield better handling and suspension characteristics on a properly setup car

Some calipers also use a differential bore design, in which smaller pistons are used up front, with larger pistons at the trailing edge of the caliper. As the surface of the brake disc heats up, the clamping force of the pistons has to be increased to maintain braking force (due to increasing fade). If the caliper has multiple pistons (or multiple pairs of pistons), the brake disc surface is initially heated by the pistons pushing against the brake pad at the leading edge of the caliper, making the disc surface hotter when it rotates back to the pistons closer to the trailing edge of the caliper. Therefore it helps if the pistons closer to the rear edge of the caliper are larger as they can deliver greater pressure.



So, with all that in mind then, why's the BMW BBK such good value?

Pros
Well, it's a basic 6 pot system (front), designed by Brembo as a two-piece aluminium caliper. It uses inexpensive standard compound Jurid/Textar brake pads (which are the regular BMW OEM pads), with basic one-piece drilled & slotted 338x26mm discs, simple individual piston dust seals and standard BMW brake hoses.

Because the caliper, and entire brake system, was designed as an OEM piece for the 135i, BMW have managed to drive the cost of that caliper down and hence can pass on the savings to the aftermarket customer. The only difference is the brake disc, which on the Performance kit is the same intrinsic disc but now drilled and slotted. The ancillaries have also been built down to a price - this is not being disrespectful to BMW, but in reality you can't imagine BMW using a £1500 brake system as standard on the 135i. For regular road use and as a standard no-thinking-required replacement for standard brakes it's a very good kit. The vast majority of BMW drivers would be very happy with this BBK as it's a fit-and-forget system And compared to the brakes on a 325i (not so much to a 335i/d) it's a vast improvement.


Cons
However, when you start exploring the higher limits of the BMW BBK there are several failings that become obvious. Firstly, it is next to impossible to get aftermarket pads for that caliper - because it's a BMW-specific caliper and not a standard Brembo shape, the likes of Pagid and Ferrodo have been very slow in developing aftermarket pads for that application. The regular BMW pads are ok for road use, but on the track they start to fade and judder very quickly. The more aggressive driver or track-day enthusiast will probably find the limits of the pad quite quickly. To be able to change to Pagid race pads for use on a track for example might be very important and necessary. Continuing this theme, it isn't easy to change the pads on the BMW BBK - the caliper has to come off. Compare that to the top-end Brembo kits where the pads are held in by quick-release pins and you can do a pad change in mere minutes.

The brake discs are one-piece items with integral bell (the bit that holds the disc onto the hub). There's no way to improve the brake disc by using aftermarket items from the likes of Performance Friction (who make arguably the world's best brake discs). The standard discs themselves also aren't as heat-resistant as they could be and will warp more easily under duress. The heat characteristics of the pistons also leave much to be desired - when out on track, under duress the pistons have a tendency to crack, whilst the seals will almost certainly disintegrate. This has been shown many times now on the 135i race cars. The caliper also displays quite uneven pressure distribution across the pistons - the last set of pads I used on my BMW BBK were noticeably warped with a 3.5mm height difference between the widest edges.

These problems only showed up when the brakes were put to more serious use. I discovered all this first hand at the Nurburgring last summer, when I subjected the brake system to only a moderately torturous test I was actually disappointed at how spectacularly the calipers failed I was reminded though that they are also spectacularly cheap and not really designed for that sort of abuse!! To BMWs credit they replaced that first kit with a new set of calipers..!

On normal road driving, the limits would not be anywhere close to being reached and so I would still recommend them as a significant performance upgrade to the standard brakes on anything up to a 330 (pre-LCI) under these conditions

I would NOT recommend the BMW BBK for someone with a 335i or 335d, as there are too many disadvantages going to the BBK compared with the regular OEM setup - the main problem is the discs are much smaller and thinner and can't absorb anywhere near the amount of heat that the OEM discs can.

A 335i/d owner would be better off keeping the OEM calipers and discs and instead change the pads to something more suitable for fast road, uprate the brake fluid to at least a DOT 4.1 level, and upgrade the OEM rubber brake hoses to stainless steel items.



My thoughts

If you are looking to use the car on a track on more than the odd occasion, or do LOTS of high-speed driving, then I would suggest you look at a higher-spec alternative. There has been mention of the £4000/£6000 Brembo GT kits etc, which are fabulous but massively over-specced for use on anything other than fully-fledged race cars.

The Tarox kits have issues of their own - the cheap kits are exactly that - cheap and nasty. The 12pot systems are ridiculously expensive, and to be honest why on earth would anyone need a 12pot system? The individual pots themselves are tiny, the weight of the caliper is huge, and the performance doesn't justify the price.

Probably the best value kit, and the one I'm now using to great effect, is the AP Racing 6pot front / 4pot rear system. The front 6pot system is a two-piece cast aluminium design using 355x32mm slotted and vented discs with separate bells, aluminium alloy pistons with individual high-temp dust seals and comes supplied with mounting brackets, braided hoses, Ferrodo DS2500 fast-road pads, and Dot 5.1 brake fluid.

The rear system uses a 4-piston version of the same caliper, Ferrodo DS2500 pads, but uses the standard rear BMW OEM discs. I believe that Stillen Racing in the USA have a different version of the rear AP system that uses replacement discs as well.

I have been using the APs for almost a year now, and I have nothing negative to say about them at all. They've handled every track day I've thrown at them, the durability is excellent, pedal feel very firm yet progressive, and are a huge improvement over the BMW BBK which I had on previously. It's no wonder they are used on so many race cars at the Nurburgring as the performance/cost ratio is staggeringly good value. I will be doing a separate write up on the APs so keep an eye out for that.

Retail cost for the complete front AP kit (CP5575-1009.G8) is £1,887 + VAT and fitting .
The rear kit (CP6625-1000BK) is £815 + VAT and fitting.
(from Birds - www.birdsauto.com)
(Product codes are for Black-coloured calipers - Red calipers also available)


Bottom line - for normal road use on anything up to a 330 (pre-LCI), get the BMW BBK. For serious use, get the APs. If you just want to spunk a load of money on the big Brembo GT brakes, buy yourself a better car first...!!!!

[remmib]

Originally Posted by bavarian19

I debated the same a while back. Might as well get 335 front brakes.

So do you know if 335 brakes fits on an 325i/328i/330i (or in my case 320d which I think has the same brakes as the 325i).

[kcleung]

wow e92fan, looks like you really have thought this through. since you have done much research on this, may I pick your brain further:

1) will 335mm disc need 18" wheel?
2) if so, do you know if ap or any other floating disc that can fit e90 w 17" wheels.

I am not happy with the stock brakes since they fade too quickly. am also aiming to take 100kg out of the car so think I dont want to buy bigger brakes unless I have to. I tthink the bmw perf bbk can fit 17" wheels but given the comments so far, I would rather pay a bit more and get something that I will be completely happy with.

Originally Posted by E92Fan

I made the post below in relation to a question a UK member posted, asking about the value of changing to the BMW BBK system and also why it was so cheap in comparison to the 'proper' BBKs like APs or Brembos. His car was a 325i, he liked to do a little track work, but mainly his car was used on motorways/highways for his work commute. Thus my response is European focussed, with UK pricing - however the principles of the post remains the same and I think it might be valuable here too.

[deecee]

is there any chance it wont fit a 19" wheel?

is it not balanced to just install the front?

[bavarian19]

Originally Posted by remmib

So do you know if 335 brakes fits on an 325i/328i/330i (or in my case 320d which I think has the same brakes as the 325i).

335 front brakes work. On some models, like the 328, the parking brake is not compatible with the rear brakes. If your PN's match up with the 328's, then it should work for you.

[jbass524]

BTW. If you really want them...http://www.e90post.com/forums/showthread.php?t=315318. Taking best offers as they are doing me no good and I won't be putting them back on.

[deecee]

so let me get clera is this a 1piece kit? I heard Brembo has 2 piece kit and its alot lighter. is this realy heavy?

[E92Fan]

Originally Posted by kcleung

wow e92fan, looks like you really have thought this through. since you have done much research on this, may I pick your brain further:

1) will 335mm disc need 18" wheel?
2) if so, do you know if ap or any other floating disc that can fit e90 w 17" wheels.

I am not happy with the stock brakes since they fade too quickly. am also aiming to take 100kg out of the car so think I dont want to buy bigger brakes unless I have to. I tthink the bmw perf bbk can fit 17" wheels but given the comments so far, I would rather pay a bit more and get something that I will be completely happy with.

You can fit a 17" wheel over a 335mm disc. The standard BMW OEM 335i brakes are 348mm in diameter, and a 17" wheel fits over those.

However, if you are going for a BBK, then it is unlikely that anything will fit under a 17" wheel due to the potential diameter of the disc and also the inner clearance to the wheel spokes.

No AP disc (for the BMW application) will fit under a 17" wheel - 18" wheel is minimum.

I suggest you go for an AP setup over the BMW BBK if you are intending to drive the car hard or on track. If it is just for normal street use, I'd stick with the OEM brakes.

[E92Fan]

Originally Posted by deecee

so let me get clera is this a 1piece kit? I heard Brembo has 2 piece kit and its alot lighter. is this realy heavy?

The BMW BBK Brembo caliper is a 2-piece caliper, and uses a 1-piece disc which is rather heavy!!

[deecee]

wtf.. so that means it increases unsprung weight???

[E92Fan]

Originally Posted by deecee

wtf.. so that means it increases unsprung weight???

If you want to decrease unsprung weight AND have a braking improvement, the BMW BBK is not the route to go.

The AP setup is lighter and more effective.

The BMW BBK disc is lighter than the OEM BMW disc, because it's that much smaller!!!

[deecee]

Originally Posted by E92Fan

If you want to decrease unsprung weight AND have a braking improvement, the BMW BBK is not the route to go.

The AP setup is lighter and more effective.

The BMW BBK disc is lighter than the OEM BMW disc, because it's that much smaller!!!

mmm so i suppose this means that using those brakes will slow the car down...

[deecee]

Originally Posted by E92Fan

If you want to decrease unsprung weight AND have a braking improvement, the BMW BBK is not the route to go.

The AP setup is lighter and more effective.

The BMW BBK disc is lighter than the OEM BMW disc, because it's that much smaller!!!

wait thats not true tho. The DISC is lighter, so isnt that mean unsprung weight is less? Only the disc spins. Though the caliper is heavier i suppose , it doesnt spin. so it only increases the car's general weight?

correct me if im wrong,,..

[E92Fan]

Originally Posted by deecee

wait thats not true tho. The DISC is lighter, so isnt that mean unsprung weight is less? Only the disc spins. Though the caliper is heavier i suppose , it doesnt spin. so it only increases the car's general weight?

correct me if im wrong,,..

I never said unsprung weight is more - the lighter disc means less unsprung weight. However, IMO the BMW BBK is a performance downgrade from the OEM 335i brake setup. So yes, you're getting less unsprung weight from the disc, but also less performance.

And yes, the caliper doesn't spin obviously. But the weight of the caliper has an effect on the suspension performance. So ideally you want a lighter caliper as well so you can maximise the reduction in unsprung weight.

However compared to the OEM brakes on a 320/325/328 etc (ie everything BUT a 335i) then the BMW BBK is definitely an upgrade in all directions.