E92 M3 brake upgrade options

[horico]

I've been going round in several circles on this one and my limited expertise isn't really pointing me in the right direction so I thought I'd seek the expertise on here.

I've got a heavy vibration on anything above light braking, accompanied with an unpleasant noise on the M3. I'm assuming there's maybe a warped disc, maybe caused by a sticking caliper, possibly due to limited use recently or some other reason. Also, there's an occasional rotational catching noise after a run - this could be the on/off sticking caliper. After a run today, none of the wheels were particularly hot - the extent of my diagnositc abilities! Either way, it will be getting diagnosed shortly by an actual mechanic.

Now, my experience of the stock brakes isn't that great - much like the E46 M3, they seem to give up the ghost quite quickly even on the road. Back a few years and I solved the E46 issue with a K Sport BBK. It seems there are a million different options right now for the E92. So far, I'm aware of the following:

1 - Replace with OEM discs, upgraded pads, braided lines and better fluid
2 - Malc Buck BTCC Kit using the Ap Racing CP 9660, BTCC discs and pads etc (no anti rattle clips and no dust seals) Approx £2.3k
3 - M4 Caliper upgrade (front and rear)
4 - 3.5k BBK from Stoptech, Brembo GT etc.
5 - Alternative AP setup from the list below (suggested by Malc Buck - aside from weight, I'm not knowledgable enough to compare). All come with lines, mounting kit, anti rattle clips, dust seals and hardware.

CP9040
362 X 32 discs
£2,155

CP8522
380 X 34 discs
£2,350

CP5555
362 X 32 discs
£2,645

CP5060
362 X 32 discs
£2,657

I would love to have faith that an oem+ setup would work but I'm also concerned I'll be in the same position in the future and I'd like to get it right this time. I don't do many miles a year but tend to enjoy those miles. I don't want to go mad on budget otherwise the brembo GT would be slapped on and job done - I also don't want to buy twice!

Also, with regard to the BTCC setup, these don't have dust seals - for low mileage use and regular cleaning, is this an issue? Would an annual check up on them come service time work if covering 2-3k miles per year?

[schuey]

I’ve gone option 1,genuine discs front and rear with Ferodo DS3000 race compound pads up front and DS2500 track day compound pads on the back and then HEL braided brake lines and race fluid. Works a charm,race front pads are a bit much on the road,fine from cold but easy to lock a wheel even at 60+mph on cold tyres and greasy roads but fine really if you’re paying attention.

Did a track day last week with this setup and front tyres were going off the boil before the brakes were struggling. By mid afternoon I was getting noise/judder from the front but that seemed to be clogged up holes in the discs from the softer front pads,rears looked untouched. It’s been fine since on the road once they cooled off and I cleaned out the holes. People I took out in it couldn’t believe how well it stopped so the combo works well. I’d love a big brake setup on it,mainly because they look cool but on road tyres not much would be gained in my opinion. If it was a pure track day machine on sticky tyres then yes,but it’s a fully furnished daily.

[TheAngryDog]

Reyland Motorsport do a bbk using AP Racing calipers with dust seals.

https://www.ebay.co.uk/itm/254535011009?mkcid=16&a...

Freaky parts do a kit that uses the standard discs I believe with 4 pot Brembo calipers.

https://freakyparts.co.uk/products/bmw-e9x-m3-brem...

[Gouki]

I went with the F80 M3 set up on my e92 M3, it's quite an involved job, but I'm impressed with the set up on track with over a 3 second per lap improvement (Sonoma Raceway) compared to stock calipers likely due increased confidence and pedal feel with the same pads (RSL 29).

[MDubyaB]

I’ve had brake judder on mine a few times. From doing a fair bit of digging online and ultimately talking to a brake specialist (buggered if I can remember who it was) it seems that modern brake discs pretty much never warp these days, but it’s still the immediate assumption people make, myself included. In my case the problem was deposits and an aggressive disc cleaning/bedding in procedure on road cured the problem.

[rosino]

On forums I had been pointed at the below for best value for money.

https://freakyparts.co.uk/products/bmw-e9x-m3-ap-r...

You keep your discs so you can use those and if you need to replace them you can always go for a better disc. I remember using amazing performance friction discs in oem size 10yrs ago that were fantastic on track.

So that could be a way to do it.

[horico]

Thanks all for the replies. It sounds like some inspection of the brakes to rule out deposits and crud in the holes may be the first thing to do. I do have the luxury of it being a weekend, or month end car so I can waste some time investigating - just a case of someone with the know-how to assist. I'd love to just stick OEM kit on with pads, lines and fluid and call it done so let's hope that's the way to go.

[JEA1K]

horico said:

Thanks all for the replies. It sounds like some inspection of the brakes to rule out deposits and crud in the holes may be the first thing to do. I do have the luxury of it being a weekend, or month end car so I can waste some time investigating - just a case of someone with the know-how to assist. I'd love to just stick OEM kit on with pads, lines and fluid and call it done so let's hope that's the way to go.

My 2p is that unless you are at the point of heavily tracking your car and or competing, then a a set of AP etc isn't worth it. If you're desperate to spend, I'd say creating a better handling car for your needs is more beneficial.

I've just upgraded my pads to Ferrodo's DS uno, along with braided hoses and fluid. As it happens, I had new brake lines as the old hoses wouldn't play ball. I'd say the difference in braking performance is significant. The pads have far more initial bite and the pedal feel is consistent ... on the OEM set up, I felt like the pedal required more pressure and after a handful of relatively hard presses, the brakes lost any initial bite, the pedal required more pressure to the point where the car just wasn't stopping anywhere near as quick enough. Plus they made it known by grumbling a lot. And this is all on road ... I haven't been on track yet and I don't drive particularly hard on the road.

For reference, I tracked both an E36 M3 GT (with an 'OEM' set up inc Pagid RS29's) and a CSL with AP's and RS29's. Yes the CSL stopped very well ... but so did the E36, the brakes felt great ... I never had brake fade on either car but one cost me significantly more to upgrade.

Just add, someone is selling this set up on cutters (not me!) ... here's the relevant bit of the advert below:

[b] Parts available are full front OEM brake discs, calipers, RS29 pads and, goodrich uprated hoses. I bought all of the brake system new last year, used it for 2 months and then went full BBK.
DISCS ARE VIRTUALLY BRAND NEW - Bought in June from Eurocarparts and were taken off in September. OEM price is £709.98 for the front pair - would sell for £450.
PAGID RS 29 pads - also virtually new. OEM price £315.95 - would sell for £225
Goodrich Braided hoses - also virtually new - fitted at the same time. RRP £125 - would sell £75 [/b]

Edited by JEA1K on Wednesday 13th April 12:09

[Tommie38]

horico said:

I've been going round in several circles on this one and my limited expertise isn't really pointing me in the right direction so I thought I'd seek the expertise on here.

I've got a heavy vibration on anything above light braking, accompanied with an unpleasant noise on the M3. I'm assuming there's maybe a warped disc, maybe caused by a sticking caliper, possibly due to limited use recently or some other reason. Also, there's an occasional rotational catching noise after a run - this could be the on/off sticking caliper. After a run today, none of the wheels were particularly hot - the extent of my diagnositc abilities! Either way, it will be getting diagnosed shortly by an actual mechanic.

Now, my experience of the stock brakes isn't that great - much like the E46 M3, they seem to give up the ghost quite quickly even on the road. Back a few years and I solved the E46 issue with a K Sport BBK. It seems there are a million different options right now for the E92. So far, I'm aware of the following:

1 - Replace with OEM discs, upgraded pads, braided lines and better fluid
2 - Malc Buck BTCC Kit using the Ap Racing CP 9660, BTCC discs and pads etc (no anti rattle clips and no dust seals) Approx £2.3k
3 - M4 Caliper upgrade (front and rear)
4 - 3.5k BBK from Stoptech, Brembo GT etc.
5 - Alternative AP setup from the list below (suggested by Malc Buck - aside from weight, I'm not knowledgable enough to compare). All come with lines, mounting kit, anti rattle clips, dust seals and hardware.

CP9040
362 X 32 discs
£2,155

CP8522
380 X 34 discs
£2,350

CP5555
362 X 32 discs
£2,645

CP5060
362 X 32 discs
£2,657

I would love to have faith that an oem+ setup would work but I'm also concerned I'll be in the same position in the future and I'd like to get it right this time. I don't do many miles a year but tend to enjoy those miles. I don't want to go mad on budget otherwise the brembo GT would be slapped on and job done - I also don't want to buy twice!

Also, with regard to the BTCC setup, these don't have dust seals - for low mileage use and regular cleaning, is this an issue? Would an annual check up on them come service time work if covering 2-3k miles per year?

Pad deposits are much more common than warped rotors. There was a Stoptech article years ago that explained the science of it. I suspect an aggressive pad would clean up the deposits and leave you vibration free. Something like a Pagid RS29L.

What is your intended usage? Road or track and if the latter, how much real track time? I say this because I have fitted aftermarket at huge expense in the past, only to then do 1 trackday per year. To be open and honest, I have fitted Brembos purely for looks in the past.

If upgrading calipers, make sure that piston sizing is correct. Lots of people get it catastrophically wrong. I have in the past too. The mistake is to do something that increases piston size in the front. That shifts bias *rearwards* which is exactly what you don’t want.

The only E92 M3 that I have driven had Stoptechs with I think Pagids. Great, but that did quite a lot of track work.

If your answer is road use only, I’d recommend good pads, unless you want the bling. Totally understandable if so!

[horico]

Tommie38 said:

Pad deposits are much more common than warped rotors. There was a Stoptech article years ago that explained the science of it. I suspect an aggressive pad would clean up the deposits and leave you vibration free. Something like a Pagid RS29L.

What is your intended usage? Road or track and if the latter, how much real track time? I say this because I have fitted aftermarket at huge expense in the past, only to then do 1 trackday per year. To be open and honest, I have fitted Brembos purely for looks in the past.

If upgrading calipers, make sure that piston sizing is correct. Lots of people get it catastrophically wrong. I have in the past too. The mistake is to do something that increases piston size in the front. That shifts bias *rearwards* which is exactly what you don’t want.

The only E92 M3 that I have driven had Stoptechs with I think Pagids. Great, but that did quite a lot of track work.

If your answer is road use only, I’d recommend good pads, unless you want the bling. Totally understandable if so!

Thanks for the further posts all.

If I could have consistent, confidence inspiring braking on road - which is all the car will do for the foreseeable - then that's perfect. If money was no object, I'd have some blingy brembos and while I'm happy to spend what's needed, I'd rather not spend twice. I do like the concept of OEM+ and retaining as mjuch originality as possible so if that can be achieved with pad, fluid and hoses - all the better.