BMW Performance Brake kit

[MarcZ4C]

I've seen a few kits on ebay recently which are meant for 1 & 3 series models. I've read somewhere that some of these can be retro fitted to the z4. My question is, what parts would need to be added or modified to fit?

 

[pokeybritches]

ECS Tuning sells the whole kit.

 

[MarcZ4C]

I did see that. Do they do the rears too?

 

[Toe-side]

What you got? There are some cheap standard upgrades available :roll:

 

[MarcZ4C]

I've got a coupe. Was fancying upgrading the calipers really.

 

[McKoval]

THe easiest and cheapest way for non-M is to go the way of brembo 4-pot calipers, which were installed in different models - you can try imprezza, evo, and last but not least alfa romeo brera
brera has 330x30 brake pads, so the caliper, with appropriate adapter will match 325x25 brake disc perfectly
the only disadvantage is that you will need to fiddle a bit with brake pads and replace the alfa pad wear connectors for the bmw ones..
and probably you will need to get some spacers as the brembo calipers aint skinny - I think you have to achieve a ET of at least 30

 

[marksdesigns]

Ive done the comparison on quite a few motors of late .. the 'cheapest' are Ceika, (look at spending around £700 for fronts etc) and they give great discounts on a full front and rear kit. look great as well!
The others in that same catagory would be Ksport and D2 with similar prices. There is also a far east supplier, 'PB brakes' usually can be found on Ebay.
If you can stand the awful graphics on the calipers then these are the lowest in price range.

Then you can start looking at the likes of Brembo, StopTech, AP, etc.
BMW performance package will be similar cost to some of these sets.

 

[GuidoK]

I did see that. Do they do the rears too?

No they do not.
I don't think there's a proper rear BBK for the z4 on the market.
The problem is the parking brake. A lot of 3 series stuff is not compatible on the rear brakes, so there's a very small market potential. (maybe D2 racing/k-sport (same manufacturer) has a kit but I don't know if the parking brake is functional)
Not having a functional parking brake is an instant MOT failure where I live (I don't know if that is the case in the UK). So a functional parking brake is (for me) a must have.

I've made my own rear bbk to match the front ECS bbk kit using the original bmw performance calipers. I used a x3 rear disc (adapted it with a lathe), e46 parking brake shoes (adapted) and some other stuff, some stuff of a e60 5 series and some stuff of a 1 series to get the park brake shoes lined up and get a good inner dust cover.
So a mixed bag of (modified) parts, but it works like a charm :lol:
So I now have 320mm rear discs with yellow 2 pot brembo (bmw performance) calipers. (stock rear discs are 294mm)
This is also a proven combination in terms of disc size (325mm front, 320mm rear: e46 330i) and in terms of calipers/pad size (135i, e90 etc).
Using a different combination like a stoptech front kit and a d2 racing rear kit may be tricky unless you can adjust the brake balance (and know what you're doing). Wrong brake balance (too much at the rear) will probably result in a crash the first corner you take :wink: (or at least it will give you a good scare :lol: )

Also when choosing a bbk you should look at if the pistons have dust seals. A lot of BBK's do not have them. That is better for a racecar or extremely track oriented cars (these seals could melt if the pads get overheated), but for a street car you risk getting dirt in the pistons which ruins your calipers (no rebuild possible, as the inner liner gets damaged and not the piston itself). Also when the piston starts to leak, you can get brake fluid over your discs which is dangerous obviously.
A (real) race car gets a complete brake overhaul after every race so they do not need dust boots.
The ECS/bmw performance calipers have dust seals, as it is an OEM part, and with expensive sets (Brembo GT etc) you can often specify if you want dust seals or not.
But I think it's an important thing to check with the manufacturer/supplier if you buy a bbk.

 

[DPG]

Not a bad price when comparing to other BBK's

http://www.bmw.co.uk/en_GB/topics/owners/accessories/accessoryDetail.accessoryId=1794.html#eyJhc19xIjoiaW5tZXRhOnByb2R1Y3RDYXRlZ29yeSUzRE1hbnVmYWN0dXJlckFjY2Vzc29yeUNhdGVnb3J5MiBpbm1ldGE6YXZhaWxhYmxlRm9yTW9kZWxTZXJpZXMlM0RCTVclMjUyMDElMjUyMFNlcmllcyUyNTIwQ291cCVDMyVBOSJ9

I'd be interested to know if its a straight fit too.

 

[Shorty]

I looked into the Genuine BMW front brake up grade to fit on the M. It looks like they are radial mounted so adapters would have to be made. At £1005 they are great value. As far as I can gather, that includes CSL discs, back plates and 6pot calipers. I will investigate further. The part no is 34110444738.

 

[jpeeters]

I'm also planning a BBK upgrade on my Z4MC, after I realized the stock setup is too limited in comparison the Porsche GT3 RS in front of me

The BMW Performance Brake kit was high on my list, until I read following enlightening post on e90post: http://www.e90post.com/forums/showthread.php?p=5038511#post5038511. I'll run Pagid pads on the stock calipers + discs until I have the funds for a proper AP/Brembo/Stoptech/Mov'it setup.

 

[Babw]

Has anyone here used the PBMW brakes exhaustively?

I think if you're buying for an aesthetic improvement then fair enough but from my first hand experience the brakes are a minimal/if any improvement over stock.

A couple laps of Snetterton in my M3 was enough to lose the brake pedal (it was the same with stock brakes and Ferodo's). Changed to AP's and brakes are consistent for a whole day.

The pads are also a real pain on change so it makes them almost obsolete for any track use. It may be a moot point (if you're considering changing for the visual upgrade) but have you tried something along the likes of RS29 and braided hoses for an improvement in feel + performance especially for road use.

Also don't buy too much into the "made by Brembo" slogan, these are as far from a set of Brembo calipers as an OEM set.

 

[GuidoK]

The BMW Performance Brake kit was high on my list, until I read following enlightening post on e90post: http://www.e90post.com/forums/showthread.php?p=5038511#post5038511.

The person who wrote that piece does not know what he's talking about as a lot of facts that he states in his post are absolutely not true:
1. he says that the calipers are 2 piece. But it is 1 piece (Which is better/stronger, but less easy to change pads. Some brembo GT sets are also 1 piece, others are 2 piece).
2. he says that aftermarket pads (other than texar/jurid) are 'next to impossible' to get because it's a bmw design. 2 min search I found ferodo and EBC (green/red/yellow), both on their official sites... (you can also get hawk pads).
3. If you get the ECS set or use z4m calipers (you'll have to adapt the caliper carrier!) you get 2 piece semi floating discs (the 1 series discs (338mm) are indeed 1 piece, and don't have the same construction as the z4m or ecs kit bmw performance discs)
Also his story about # of pots and increase in brake travel etc is more complicated than he says as a caliper with a lot of pots has smaller pots so the displacement of fluids can be just as much, or less, or more than stock. I have no real difference in brake travel. And if there was some difference.. going from 1 to 6 pots my pedal should be on the floor :lol: .
More pots means pressure more distributed on the area of the pad and is necessary when the pads get larger. And the brembo pads are massive, even quite a bit larger in area than the (more expensive) ap brake set he recommends.
The biggest difference in track sets (AP, brembo GT, stoptech) is that you can get them with massive discs. 380mm and larger. That is where the real upgrade in braking lies, as these discs are way better at heat dissipation as their surface area is much bigger (and that's what it's all about with frequent braking on steel discs)

 

[Talksthetorque]

I thought the main advantage with larger disks was that the friction area is further away from the axis of rotation, and therefore provided better retardation for the same amount of pressure?

I agree that they will dissipate heat faster due to
a) larger surface area
b) the venting vanes between the disks will be travelling faster.

 

[GuidoK]

and therefore provided better retardation for the same amount of pressure?

No. Every caliper is probably strong enough to provide the force up to blocking the wheels. Large discs are only there to dissipate more energy, so you can brake hard more often or longer continiously before fading starts. So thats the plus side.
The downside is that larger discs are heavier, and that is unsprung weight. That means less handling. It's also rotational weight which gets further away from the axis, so that requires energy² to accelerate as that increases the effective mass greatly, and has a gyroscopic effect (limits handling). Just as you want your wheels as light as possible, you want your discs as light as possible as well.
So use the discs just as large as needed to get the job done. Any larger only comes with disadvantages. How big depends on the track&temperature but also greatly on the mass of the car (a small lotus can have tiny brakes and still outperform most cars )

I agree that they will dissipate heat faster due to
b) the venting vanes between the disks will be travelling faster.

I dont know if air will move faster through the vanes. The air is scooped from the inside out (to prevent the bearings getting all dirt and moisture channeled towards them), and that vane speed (in the inside by the hat) is the same for a small disc as for a large disc. The design of the vanes and spacing probably effects the venting of air and every manufacturer will have it's own design theories about that

 

[pokeybritches]

True. This is why I'm still on the stock calipers with upgraded Stoptech pads and rotors.

 

[jpeeters]

Thank you for the valuable information GuidoK. Looks like I'll need to do more research to find the ideal brake setup :?