8 piston Front Brakes for Z4M?

[FD3S]

Hello guys,

Today I was at my mechanic for an issue that my car had. He showed to me those 8 piston brakes that he is selling me for 1000 Euros.
He says that those are from an Audi R8 and they will fit as front brake replacement for my car, with discs of M3 E92 which are bigger than the E46 CSL that our ours. The price is really low so I am thinking of it since I need new discs also.

What do you think is a good fit? 8 piston sound like an overkill for me. And by changing so drastically the braking power I wonder in a emergency brake situation with lots of kilometres if it will destabilise the rear of the car.

The next option is to buy new discs only, or to bite the bullet and pay 2500 at least for some stoptech or brembo.

 

[Mangozac]

That's a pretty major change and has a LOT of contributing factors to determine how feasible it is.
- what will the resulting brake bias be (compare the current rotor diameter and piston area to the proposed)
- will they bite too much (M4 uses a weaker brake booster with the 6 pot caliper option).
- you would want to make sure that if the fitment with the E9x rotor doesn't work as he says that you are able to return them!

Also, from the pics they don't look to be in great condition.

 

[Pastry]

I’m in the middle of fitting BMW 6 piston calipers on my M. They are a performance calipers for a 135i or 3 series i believe and is a fairly easy conversion. You have to get a custom carrier and longer brake hoses but they use the standard Z4 M disc

 

[Vanne]

I wouldent go either of these routes mate, save up for a tried and proven bbk set from a company that knows what they are doing, stoptech or any of the other well known sets. Brakes are important, dont gamble with your life.

 

[Franzino]

I wouldent go either of these routes mate, save up for a tried and proven bbk set from a company that knows what they are doing, stoptech or any of the other well known sets. Brakes are important, dont gamble with your life.

100% my thoughts exactly! That is why I bought a set of AP racing braking back in the days....

 

[FD3S]

I wouldent go either of these routes mate, save up for a tried and proven bbk set from a company that knows what they are doing, stoptech or any of the other well known sets. Brakes are important, dont gamble with your life.

I wouldent go either of these routes mate, save up for a tried and proven bbk set from a company that knows what they are doing, stoptech or any of the other well known sets. Brakes are important, dont gamble with your life.

100% my thoughts exactly! That is why I bought a set of AP racing braking back in the days....

Those are my thoughts also, but my mechanic is sure that it would be perfect. I do not race the car but often the car goes near at its top speed limit so i don't wanna loose the nose of the car in a emergency brake. I have lost a friend that way...
I will hear your advice and skip that offer.

 

[FD3S]

That's a pretty major change and has a LOT of contributing factors to determine how feasible it is.
- what will the resulting brake bias be (compare the current rotor diameter and piston area to the proposed)
- will they bite too much (M4 uses a weaker brake booster with the 6 pot caliper option).
- you would want to make sure that if the fitment with the E9x rotor doesn't work as he says that you are able to return them!

Also, from the pics they don't look to be in great condition.

Mangozac thanks for the answer. Great questions that I don't know the answers.
I noticed the same about the condition but I couldn't decide if it is due of the poor painting or for every other reason. Anyway it is better I think to skip.

 

[FD3S]

I’m in the middle of fitting BMW 6 piston calipers on my M. They are a performance calipers for a 135i or 3 series i believe and is a fairly easy conversion. You have to get a custom carrier and longer brake hoses but they use the standard Z4 M disc

Those BMW performance seem really good. Let me know please when you fit them, your comments. Thank you.

 

[robjones888]

Bmw performance six pots are made by Brembo and Work great , add to the cars character rather than detract which can happen if you fit the wrong calipers read 8 pot Audi (IMO) .Shouldnt cost more than a grand for new six pot performance calipers and mounting brackets.Bolt straight on so an afternoons work to fit , change to braided lines and bleed up. If you can’t get a decent price pm me and I’ll ask the race guy I bought mine off.

 

[TomK]

Bmw performance six pots are made by Brembo and Work great , add to the cars character rather than detract which can happen if you fit the wrong calipers read 8 pot Audi (IMO) .Shouldnt cost more than a grand for new six pot performance calipers and mounting brackets.Bolt straight on so an afternoons work to fit , change to braided lines and bleed up. If you can’t get a decent price pm me and I’ll ask the race guy I bought mine off.

The Audi R8 calipers are also made by brembo so not quite sure why you think the bmwp ones will "add to the cars character" and the r8 ones are "wrong"?
The bmwp calipers like the R8 ones were never designed for this car, but as you say they do work ok. Not to say though that you can't get the r8 ones to work also and they be ok imo.
The advantage of the bmwp calipers is that they are cheap and you can get the aftermarket mounting bracket for these cars relatively easily. The disadvantages are that they are heavy, bulky and the pistons are known to crack (never happened to me though I must say). If you just want a better feel and looks they're fine, serious track work I would look elsewhere.

 

[Beedub]

AP in my experience are incredible... Price point is suitably bonkers.

 

[craig3.2]

I’m in the middle of fitting BMW 6 piston calipers on my M. They are a performance calipers for a 135i or 3 series i believe and is a fairly easy conversion. You have to get a custom carrier and longer brake hoses but they use the standard Z4 M disc

Those BMW performance seem really good. Let me know please when you fit them, your comments. Thank you.

I have had the BMW performance calipers fitted for 3 years or so now,and find them a very good improvement over the standard M brakes.
They stop better and resist fade alot better than the standard ones,and I got mine at a very good discounted price from a bmw dealer called Sopers,along with the performance brake pads to go with them.
They are basically the brembo gt2400 kit,which costs round £2,400 in the UK when I priced mine....I got the bmwp Calipers ,bmwp pads and new z4m discs as well as custom CNC machined caliper carriers,and custom braided stainless steel hel brake hoses,for under £900 in total,plus fitting
The only thing is you need to fit (hubcentric)12mm Spacers ,so they clear the Calipers,as they don't clear the standard z4m alloys otherwise
Big improvement on Standard,imo

 

[Beedub]

Stock brakes in your case OP sound like they are more than adequate with a fluid and pad change, and braided lines if you choose too.

 

[Vanne]

This, as Bee said, the Stock OEM claws are actually pretty darn good, and pretty darn effective with the right pads and fluids. Loved mine before upgrading.

 

[TomK]

They are basically the brembo gt3400 kit,which costs round £2,400 in the UK when I priced mine..)

Lol, they are nothing like the brembo GT kit!! Those calipers are a world apart from those used for the bmwp calipers.

 

[hopz121]

They are basically the brembo gt3400 kit,which costs round £2,400 in the UK when I priced mine..)

Lol, they are nothing like the brembo GT kit!! Those calipers are a world apart from those used for the bmwp calipers.

I was just thinking the same haha

 

[craig3.2]

They are basically the brembo gt3400 kit,which costs round £2,400 in the UK when I priced mine..)

Lol, they are nothing like the brembo GT kit!! Those calipers are a world apart from those used for the bmwp calipers.

I was just thinking the same haha

Just going by what info I got from various places and suppliers,that the bmwp calipers are "basically the same" as the brembo gt kit,and they are just rebranded brembo calipers,as BMW don't make brake calipers,etc!
They are obviously not going to be exactly the same,but are based on them apparently....the gt kit cost around £2400 when I got my bmwp ones,a few years back,the bmwp were £900(including new caliper carriers,BMW performance pads,and custom braided stainless steel brake lines)plus £300 for new front discs ,so about £1200 all in,so half the price.....but I wouldn't say they are half the quality,having driven cars with both kits on,not any difference in braking performance,etc,imo.

 

[TomK]

Lol, they are nothing like the brembo GT kit!! Those calipers are a world apart from those used for the bmwp calipers.

I was just thinking the same haha

Just going by what info I got from various places and suppliers,that the bmwp calipers are "basically the same" as the brembo gt kit,and they are just rebranded brembo calipers,as BMW don't make brake calipers,etc!
They are obviously not going to be exactly the same,but are based on them apparently....the gt kit cost around £2400 when I got my bmwp ones,a few years back,the bmwp were £900(including new caliper carriers,BMW performance pads,and custom braided stainless steel brake lines)plus £300 for new front discs ,so about £1200 all in,so half the price.....but I wouldn't say they are half the quality,having driven cars with both kits on,not any difference in braking performance,etc,imo.

Good salesmen you got there The Brembo GT kit I guess you could say is 'basically the same', in that they both provide a retardation function for the car That's about it!
I ran the bmwp calipers for a year or so 5 years ago. Even with RS-29 pads trust me they are not remotely on a level of a pukka AP or Brembo GT kit. I'd accept that it requires some serious work though to see the difference, but when you do it's plain, if you're never going to push them that hard I wouldn't worry about it. There's a reason why the bmwp calipers are less than £500, and that's not BMW selling you a brembo bargain.

 

[craig3.2]

I was just thinking the same haha

Just going by what info I got from various places and suppliers,that the bmwp calipers are "basically the same" as the brembo gt kit,and they are just rebranded brembo calipers,as BMW don't make brake calipers,etc!
They are obviously not going to be exactly the same,but are based on them apparently....the gt kit cost around £2400 when I got my bmwp ones,a few years back,the bmwp were £900(including new caliper carriers,BMW performance pads,and custom braided stainless steel brake lines)plus £300 for new front discs ,so about £1200 all in,so half the price.....but I wouldn't say they are half the quality,having driven cars with both kits on,not any difference in braking performance,etc,imo.

Good salesmen you got there The Brembo GT kit I guess you could say is 'basically the same', in that they both provide a retardation function for the car That's about it!
I ran the bmwp calipers for a year or so 5 years ago. Even with RS-29 pads trust me they are not remotely on a level of a pukka AP or Brembo GT kit. I'd accept that it requires some serious work though to see the difference, but when you do it's plain, if you're never going to push them that hard I wouldn't worry about it. There's a reason why the bmwp calipers are less than £500, and that's not BMW selling you a brembo bargain.

No salesman,as I chose the kit I put only car myself,and the Calipers were circa £600/650,with discount,,and all in,with pads,etc are around £1200, including new discs.
Nobody gave me a sales pitch.

I guess I just never drive my car quick enough to have to give my brakes "some serious work",as you say,to tell the difference between the two then ,Tom

 

[FD3S]

Stock brakes in your case OP sound like they are more than adequate with a fluid and pad change, and braided lines if you choose too.

This, as Bee said, the Stock OEM claws are actually pretty darn good, and pretty darn effective with the right pads and fluids. Loved mine before upgrading.

So true. I never race the car, so the brakes almost never heat up so much or don't have enough power to stop the car. They stock brakes are very good for me, up to the moment. The only reason I am thinking of it since I need to upgrade the discs, and the same time I am saving so I can go with the SC way. Beedub do you believe someone with SC needs, brake upgrade with SC?