Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.

Brake upgrade - are these compatible? Suggestions?

"M" Specific discussion
User avatar
bmwaddict
Senior Member
Senior Member
Posts: 1148
Joined: Mon Mar 07, 2016 8:55 pm
Location: West Herts/East Bucks

Brake upgrade - are these compatible? Suggestions?

Post by bmwaddict » Wed Dec 27, 2017 1:38 pm

Thanks for the info. :thumbsup:
Currently zedless :(

'07 Mugello Blue Audi B7 RS4 Saloon with added goodies
'94 Black/Silver/Green Honda CBR400RR
Previous:
'07 Ruby Black Z4MC
'07 Sapphire Black Z4C 3.0si Sport

User avatar
MrPT
Lifer
Lifer
Posts: 4745
Joined: Sun Oct 21, 2012 7:44 pm
Location: Bucks/Oxon

Brake upgrade - are these compatible? Suggestions?

Post by MrPT » Wed Dec 27, 2017 1:40 pm

bmwaddict wrote: Wed Dec 27, 2017 1:38 pm Thanks for the info. :thumbsup:
BBK shopping is what always happens when the weather is this sh*t. :D

I think it's worth thinking about for weight reduction too. Between lighter weight alloys and caliper upgrades you can save >30kg of unsprung mass vs stock pretty easily. In performance terms that's massive.

User avatar
bmwaddict
Senior Member
Senior Member
Posts: 1148
Joined: Mon Mar 07, 2016 8:55 pm
Location: West Herts/East Bucks

Brake upgrade - are these compatible? Suggestions?

Post by bmwaddict » Wed Dec 27, 2017 2:01 pm

:D
You've helped add to my already huge shopping list!
Yeah definitely, my Breytons are about half the weight of the Linea Corses I had on before, can't wait to get them on.
Currently zedless :(

'07 Mugello Blue Audi B7 RS4 Saloon with added goodies
'94 Black/Silver/Green Honda CBR400RR
Previous:
'07 Ruby Black Z4MC
'07 Sapphire Black Z4C 3.0si Sport

User avatar
Attilio
Member
Member
Posts: 763
Joined: Tue Oct 31, 2017 11:11 am
Location: Dublin

Brake upgrade - are these compatible? Suggestions?

Post by Attilio » Wed Dec 27, 2017 8:06 pm

MrPT wrote: Wed Dec 27, 2017 11:37 am This is the kit I have:

https://www.vagbremtechnic.com/front-ca ... cs-ak0007/

Image

Brackets and hoses are £250, or £850 including new calipers from Aston Martin. You can also find the calipers s/h from eBay or astonmartinbits.com for about £400 (inc DIY refurb), but they are not as common as the Porsche calipers mentioned by bradz.

I was in a similar situation to you last year and liked the sound of these because the front piston area is within a couple of % of the stock Z4M caliper, so is a good match for the brake master cylinder and therefore preserves pedal travel and braking force. BMW Performance calipers have a ~14% smaller piston area; Porsche 996 / Boxster S are ~20% smaller (front and back). The downside with the VBT kit is that there is no equivalent rear kit available that preserves the stock brake bias. Hypothetically it would be a 4-pot caliper with 31 and 33mm pistons.

If you need new discs and pads and the same time and are thinking of going for a higher performance pad, the cheaper Reyland AP kits are also worth considering, although again you’d need to got front + rear to preserve brake bias (and then you are into >£2k territory). Just upgrading pads and brake cooling would also be a good move if you aren’t too fussed about looks.
Thanks everyone and thanks MrPT,

very useful information and thanks for the picture and link. I am starting to realise this is going to be a very expensive project: it is going to require a set of 19' wheels too (or at least spacers - and I am not keen on those).

I might get the new discs and pads and see what my finances are like when I have to replace the tyres (I might get 19' alloys + tyres then) and then upgrade the calipers at a later stage.

I didn't realise it was possible to fit the Boxster S callipers...however, when you factor callipers and pads all round + adapters you are indeed into >2k territory as you said... let's hope the sales commissions in 2018 will be better than those in 2017 :(
Z4M Coupe, Interlagos blue, black leather, piano black, stubby, OEM CSLs, evolve intake, cup holders...pretty much stock
2019 Toyota Corolla hybrid 2.0L - new daily drive

FD3S
Member
Member
Posts: 243
Joined: Sat May 14, 2011 11:18 pm

Brake upgrade - are these compatible? Suggestions?

Post by FD3S » Wed Dec 27, 2017 11:05 pm

It is time also for me to change discs and the pads. I was thinking to upgrade to a bigger 6 and 4 pot system but those systems from Brembo, AP Racing and Stoptech cost a leg and an arm.
It is good that I see that there a many other solutions.

My question is if you believe that for a car that never sees racetrack, if it makes sense any upgrade to the brake system? What results should someone expecting when having such an upgrade? Is it something measurable?
Last edited by FD3S on Wed Dec 27, 2017 11:06 pm, edited 1 time in total.

User avatar
MrPT
Lifer
Lifer
Posts: 4745
Joined: Sun Oct 21, 2012 7:44 pm
Location: Bucks/Oxon

Brake upgrade - are these compatible? Suggestions?

Post by MrPT » Thu Dec 28, 2017 12:42 am

FD3S wrote: Wed Dec 27, 2017 11:05 pm My question is if you believe that for a car that never sees racetrack, if it makes sense any upgrade to the brake system? What results should someone expecting when having such an upgrade? Is it something measurable?
I did it on the back of driving an Elise S2 and 997 C4S in anger on some of the UK’s best roads. The Z4M stops just as violently as them if you mash the brake pedal, but the feel of their brakes is so much better. This is partly because of the slightly over-servoed nature of the ///M brakes (non-M is more progressive and natural, in my opinion) but also, I’m sure, because of their multi-pot calipers. They just seemed to have more consistent pedal feel, and for longer. It was most noticeable when heel & toeing down through more than one gear or when driving downhill through switchbacks. Whether this is because of better cooling or improved stability of the pad against the disc, I don’t know - suspect it’s a combination of both. People have had good results just by improving front brake cooling on our cars, but the aesthetic benefits of going to 4 or 6 pot calipers are hard to ignore!
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

User avatar
bradz
Member
Member
Posts: 455
Joined: Thu Jul 11, 2013 6:26 pm
Location: Bedford

Brake upgrade - are these compatible? Suggestions?

Post by bradz » Thu Dec 28, 2017 1:09 am

MrPT wrote: Wed Dec 27, 2017 1:36 pm
bmwaddict wrote: Wed Dec 27, 2017 12:31 pm
MrPT wrote: Wed Dec 27, 2017 11:55 am Here are the part numbers of the calipers mentioned above, FYI:

2F9DB24B-A05C-4DDB-B357-D67594ED9498.jpeg

Last two characters of the Aston ones are the colour code.
So what are you running at the rear Paul?
Standard M calipers?
Yes, just tarted up a bit to match the fronts.
bradz wrote: Wed Dec 27, 2017 12:33 pm Whilst I'm not disagreeing with the tech info, there certainly was a reduction in pedal travel when I fitted the 6 pots. (Compared to freshly bled stock fronts)
That does makes sense though. Those 6 pots have less total piston volume than stock, so there will be more piston travel per unit of pedal travel. Pairing them with the 996 rears means there's a bit of a shift from the stock brake bias to the front, but I'm not sure how much us mere mortals would be able to tell. You'd also hope that every option we've discussed is still going to hit the limits of the road/tyres before their own.

The combos to avoid, in my opinion, are just changing the fronts to BMW Performance or Porsche 996 calipers and keeping the stock rears. Big change in brake bias rearwards, and the kind of thing you'd probably find out for the first time when someone's cat suddenly runs out in front of you. :cry:
I can honestly say running the BMW proformance calipers and stock rears isn't a problem. After 17 laps of the Nurburgring chasing times this caused no noticeable unbalance of the car during heavy breaking.
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

Mangozac
Senior Member
Senior Member
Posts: 1103
Joined: Sat Aug 08, 2009 5:33 am
Location: QLD, Australia
Contact:

Brake upgrade - are these compatible? Suggestions?

Post by Mangozac » Thu Dec 28, 2017 2:08 am

Monaco84 wrote: Wed Dec 27, 2017 8:01 am
Mangozac wrote: Tue Dec 26, 2017 11:49 pmHey Bradz what calipers are these?
bradz wrote: Tue Dec 26, 2017 8:35 pmFor the rear I have got 996 Brembo 4 pots
you also need adaptors for the rear. Epytec might have them as well
bradz wrote: Tue Dec 26, 2017 8:35 pmAdaptors from epytec are about £140 iirc
Ahh my apologies I just reread your post - when I first read it I thought you meant that they were BMW calipers.
Current: 06 E85 M Silbergrau
Previous: E85 3.0si Silbergrau, 03 E85 2.5i Maldives Blue.
Mods: Gaptech OTH+R, Dension Gateway 300 with USB, CDV-, clear side indicators, euro tails, stubby, MFSW retrofit, OEM Bluetooth/VR

User avatar
Attilio
Member
Member
Posts: 763
Joined: Tue Oct 31, 2017 11:11 am
Location: Dublin

Brake upgrade - are these compatible? Suggestions?

Post by Attilio » Thu Dec 28, 2017 9:51 am

Bradz, MrPT,

Incredibly useful information, thank you!
Z4M Coupe, Interlagos blue, black leather, piano black, stubby, OEM CSLs, evolve intake, cup holders...pretty much stock
2019 Toyota Corolla hybrid 2.0L - new daily drive

User avatar
Attilio
Member
Member
Posts: 763
Joined: Tue Oct 31, 2017 11:11 am
Location: Dublin

Brake upgrade - are these compatible? Suggestions?

Post by Attilio » Thu Dec 28, 2017 9:58 am

FD3S wrote: Wed Dec 27, 2017 11:05 pm It is time also for me to change discs and the pads. I was thinking to upgrade to a bigger 6 and 4 pot system but those systems from Brembo, AP Racing and Stoptech cost a leg and an arm.
It is good that I see that there a many other solutions.

My question is if you believe that for a car that never sees racetrack, if it makes sense any upgrade to the brake system? What results should someone expecting when having such an upgrade? Is it something measurable?
Very good question you raised about the usage of the car: I am not planning to track the car, so perhaps it would make sense to just upgrade the brake lines (with braided ones) and fit EBC or similar pads when the time to replace the discs comes?
Z4M Coupe, Interlagos blue, black leather, piano black, stubby, OEM CSLs, evolve intake, cup holders...pretty much stock
2019 Toyota Corolla hybrid 2.0L - new daily drive

User avatar
MrPT
Lifer
Lifer
Posts: 4745
Joined: Sun Oct 21, 2012 7:44 pm
Location: Bucks/Oxon

Brake upgrade - are these compatible? Suggestions?

Post by MrPT » Thu Dec 28, 2017 10:04 am

bradz wrote: Thu Dec 28, 2017 1:09 am
MrPT wrote: Wed Dec 27, 2017 1:36 pm The combos to avoid, in my opinion, are just changing the fronts to BMW Performance or Porsche 996 calipers and keeping the stock rears. Big change in brake bias rearwards, and the kind of thing you'd probably find out for the first time when someone's cat suddenly runs out in front of you. :cry:
I can honestly say running the BMW proformance calipers and stock rears isn't a problem. After 17 laps of the Nurburgring chasing times this caused no noticeable unbalance of the car during heavy breaking.
Nice! Same pads front and back? Front and rear tyres in similar condition? It might just be that the stock brake bias is very conservative (front biased) and you've neutralised all of the safety margin. I still stand by my comment - it's a risk that shouldn't be taken lightly by most of us. You are lucky in that you have a lot of opportunities to check the performance of your car at or near the limit.

Have you put the Porsche rears on now? Would be interested in how they feel in comparison to just the BMW Ps up front.
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

User avatar
bradz
Member
Member
Posts: 455
Joined: Thu Jul 11, 2013 6:26 pm
Location: Bedford

Brake upgrade - are these compatible? Suggestions?

Post by bradz » Thu Dec 28, 2017 11:42 am

MrPT wrote: Thu Dec 28, 2017 10:04 am
bradz wrote: Thu Dec 28, 2017 1:09 am
MrPT wrote: Wed Dec 27, 2017 1:36 pm The combos to avoid, in my opinion, are just changing the fronts to BMW Performance or Porsche 996 calipers and keeping the stock rears. Big change in brake bias rearwards, and the kind of thing you'd probably find out for the first time when someone's cat suddenly runs out in front of you. :cry:
I can honestly say running the BMW proformance calipers and stock rears isn't a problem. After 17 laps of the Nurburgring chasing times this caused no noticeable unbalance of the car during heavy breaking.
Nice! Same pads front and back? Front and rear tyres in similar condition? It might just be that the stock brake bias is very conservative (front biased) and you've neutralised all of the safety margin. I still stand by my comment - it's a risk that shouldn't be taken lightly by most of us. You are lucky in that you have a lot of opportunities to check the performance of your car at or near the limit.

Have you put the Porsche rears on now? Would be interested in how they feel in comparison to just the BMW Ps up front.
Ds2500's all round on a fresh set of MPSS for that trip.

I Still need to refit the Sub-frame! Hopefully Jan will be a quiet month work wise so I can get cracking! But yes I'm interested to see how they will feel. I was happy with the sock rears performance wise to be honest, the main reason for going down the Porsche rears is aesthetic reasons!
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

User avatar
bradz
Member
Member
Posts: 455
Joined: Thu Jul 11, 2013 6:26 pm
Location: Bedford

Brake upgrade - are these compatible? Suggestions?

Post by bradz » Thu Dec 28, 2017 11:43 am

Attilio wrote: Thu Dec 28, 2017 9:51 am Bradz, MrPT,

Incredibly useful information, thank you!
Your very welcome :D
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

FD3S
Member
Member
Posts: 243
Joined: Sat May 14, 2011 11:18 pm

Brake upgrade - are these compatible? Suggestions?

Post by FD3S » Thu Dec 28, 2017 8:18 pm

MrPT wrote: Thu Dec 28, 2017 12:42 am
FD3S wrote: Wed Dec 27, 2017 11:05 pm My question is if you believe that for a car that never sees racetrack, if it makes sense any upgrade to the brake system? What results should someone expecting when having such an upgrade? Is it something measurable?
I did it on the back of driving an Elise S2 and 997 C4S in anger on some of the UK’s best roads. The Z4M stops just as violently as them if you mash the brake pedal, but the feel of their brakes is so much better. This is partly because of the slightly over-servoed nature of the ///M brakes (non-M is more progressive and natural, in my opinion) but also, I’m sure, because of their multi-pot calipers. They just seemed to have more consistent pedal feel, and for longer. It was most noticeable when heel & toeing down through more than one gear or when driving downhill through switchbacks. Whether this is because of better cooling or improved stability of the pad against the disc, I don’t know - suspect it’s a combination of both. People have had good results just by improving front brake cooling on our cars, but the aesthetic benefits of going to 4 or 6 pot calipers are hard to ignore!
Thank you for your detailed answer.
Is the aesthetic benefit so important than to give 4500 euros for new brakes? :D I haven't decided yet...
Btw how can someone improve the front brake cooling?

FD3S
Member
Member
Posts: 243
Joined: Sat May 14, 2011 11:18 pm

Brake upgrade - are these compatible? Suggestions?

Post by FD3S » Thu Dec 28, 2017 8:26 pm

Attilio wrote: Thu Dec 28, 2017 9:58 am
FD3S wrote: Wed Dec 27, 2017 11:05 pm It is time also for me to change discs and the pads. I was thinking to upgrade to a bigger 6 and 4 pot system but those systems from Brembo, AP Racing and Stoptech cost a leg and an arm.
It is good that I see that there a many other solutions.

My question is if you believe that for a car that never sees racetrack, if it makes sense any upgrade to the brake system? What results should someone expecting when having such an upgrade? Is it something measurable?
Very good question you raised about the usage of the car: I am not planning to track the car, so perhaps it would make sense to just upgrade the brake lines (with braided ones) and fit EBC or similar pads when the time to replace the discs comes?
My thoughts are the same. Brake line upgrade new discs and better pads. The only possibility I was thinking the 6 piston is that maybe within the next year I decide to go the SC way. Anyway decisions, decisions. However the aesthetics is indeed something important.

Post Reply