A real good brake setup

[the bruce]

Any idea on difference (if any) in piston size between the rear calipers on:

Golf/GTI/A3

R32/S3/Golf R

Rotor size goes from 289mm to 310mm.

Mk.V GTI: C38 caliper - 38 mm: 1134 mm² (286 x 12 mm rotor)
R32/R/S3/RS3: C41 caliper - 41 mm: 1288 mm² (310 x 22 vented rotor)


Not a huge difference, but in conjunction with the increased diameter
it gives 13.5 % + 8.4 % = 21.9 % more rear brake power on a GTI
which changes brake balance.


:wink:

 

[Talguy]

All the guys I know that have done this swap love the setup. As you state "great bang for the buck". Fits a large amount of wheels with only a small spacer.

My 2 peice rotors from coleman havent held up well with my 17Z setup and that was with almost all street driving. This year Im hoping to downsize just a little for better balance.

I have some boxster S calipers and some new brackets to try out on my car very soon. They use a slightly larger 320mm rotor. The pad should cover a larger swept area as the pad is quite a bit taller than the non S pad. The S pads have a build in damper also which should negate some of the pad squeal that a fair amount of people complain about.

I have a set of HPS pads for them but if I decide to keep them on my personal car Ill swap them out for Porterfield R4S pads.

If anyone is interested Ill have at least one spare set of calipers and brackets.

Cruizin, what were the problems you were having with the coleman rotors?

 

[penance]

Cruizin, what were the problems you were having with the coleman rotors?

Yeah... I'm curious as well.

My colemans seem fine so far... but one is slightly warped. I just haven't gotten it looked at yet.

 

[cruizin01]

Cruizin, what were the problems you were having with the coleman rotors?

I cant say 100% its the rotors fault, but something between them and the porterfield pads I run. I have had bad pad deposit issues which have in turn resulted in small cracks. One nice hard "higher" speed stop will leave deposits that I can only get rid of by driving normally for quite a few miles. You can see them as circular dark spots in the rotor surface. I've used these pads on numerous other brand rotors with no issues. Ive spoke to a couple of resellers and they seem to think its just a possible bad combination of rotor and pad ingredients. Im just not looking to run a different pad as I love the R4-S

I've gotten ZERO support from Coleman (after multiple emails) on what might be causing the problem. Ive gone through 2 sets of $200 pads and a $400 set of blanks and just dont want to do it again. So I'm going back to something a bit simpler and cheaper to work with. Especially since the car is mainly a street car its stupid to waste this kind of money on it.

Sorry for the thread jack.

 

[miamirice]

I cant say 100% its the rotors fault, but something between them and the porterfield pads I run. I have had bad pad deposit issues which have in turn resulted in small cracks. One nice hard "higher" speed stop will leave deposits that I can only get rid of by driving normally for quite a few miles. You can see them as circular dark spots in the rotor surface. I've used these pads on numerous other brand rotors with no issues. Ive spoke to a couple of resellers and they seem to think its just a possible bad combination of rotor and pad ingredients. Im just not looking to run a different pad as I love the R4-S

I've gotten ZERO support from Coleman (after multiple emails) on what might be causing the problem. Ive gone through 2 sets of $200 pads and a $400 set of blanks and just dont want to do it again. So I'm going back to something a bit simpler and cheaper to work with. Especially since the car is mainly a street car its stupid to waste this kind of money on it.

Sorry for the thread jack.

Now this can be a whole issue of rotor - pad transfer layer. To keep it short, you must merry the rotor to the track pad you will use....period. The only way around this is to stay in the family of some producers ( example is carbo tech, you can trade in street pads and back to say...xp12 if you stay with there pads. Other wise, Forget it. I would just say if you plan to use 2 manufacturers of pads, plan to use 2 rotor set ups.

 

[cruizin01]

Now this can be a whole issue of rotor - pad transfer layer. To keep it short, you must merry the rotor to the track pad you will use....period. The only way around this is to stay in the family of some producers ( example is carbo tech, you can trade in street pads and back to say...xp12 if you stay with there pads. Other wise, Forget it. I would just say if you plan to use 2 manufacturers of pads, plan to use 2 rotor set ups.

Ive only been using the R4-S pad. No pad swapping. For the few track days I do I can get by with the R4-S pad. Thats why I dont want to switch.

 

[miamirice]

Are you sure you followed the bedding proceedure carefully? There is some good info on the Stoptech website.

 

[cruizin01]

Are you sure you followed the bedding proceedure carefully? There is some good info on the Stoptech website.

I had these same pads on 2 other cars, along with a set on on the stock GTI brakes, along with a set in the 17z's with 1 peice rotors with no issues. So I feel I've got a good understanding on these. :biggrin: Issues started with the coleman blanks. I thought maybe I got a bad set of pads or something, so I had the rotors turned just a little and matched another new set to them. Same issues.

 

[bostonaudi]

I had these same pads on 2 other cars, along with a set on on the stock GTI brakes, along with a set in the 17z's with 1 peice rotors with no issues. So I feel I've got a good understanding on these. :biggrin: Issues started with the coleman blanks. I thought maybe I got a bad set of pads or something, so I had the rotors turned just a little and matched another new set to them. Same issues.

I had similar issues w/RB rotors and deposits and finally gave up. Have never had issues with Hawk pads, and switching from HPS street pads to DTC-60 for track weekends has worked well. Have had similar good results with EBC pads but for me Hawk is way to go.

 

[miamirice]

I had these same pads on 2 other cars, along with a set on on the stock GTI brakes, along with a set in the 17z's with 1 peice rotors with no issues. So I feel I've got a good understanding on these. :biggrin: Issues started with the coleman blanks. I thought maybe I got a bad set of pads or something, so I had the rotors turned just a little and matched another new set to them. Same issues.

Ok. The only thing I can say regarding your experience, for track/race experience, turning rotors is a very temporary measure. ( as in getting 1 more day or race out of them). If you are really heating then up ( glowing orange/red) the metal on the rotor will change under the hot spot. You turn them, and they do the same thing in the same spot. We measured our rotor temp in pit lane AFTER 1 cool down lap and they are right at 1000 degrees. So look at the last paragraph under "the nature of braking friction".

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

 

[cruizin01]

Ok. The only thing I can say regarding your experience, for track/race experience, turning rotors is a very temporary measure. ( as in getting 1 more day or race out of them). If you are really heating then up ( glowing orange/red) the metal on the rotor will change under the hot spot. You turn them, and they do the same thing in the same spot. We measured our rotor temp in pit lane AFTER 1 cool down lap and they are right at 1000 degrees. So look at the last paragraph under "the nature of braking friction".

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Ive read that before but forgot quite a bit of it. Sounds like cementite inclusions may have formed early on and theres no way to fix that aside from replacing them. Why that happened I dont really know.

 

[miamirice]

Ive read that before but forgot quite a bit of it. Sounds like cementite inclusions may have formed early on and theres no way to fix that aside from replacing them. Why that happened I dont really know.

Not saying its your issue, just food for thought. We run a 5 series in chumpcar, our typical racqe is 14 hour and have run upto 24 hour. So driving a big, heavy and pretty fast car has required us to be very brake savy.

Personally I tend to treat rotors as a freq. disposable item. They get 4-6days of HPDE then they have tons of heat stress cracks and I toss them. Also, if you track a lot, when did you last rebuild your calipers? The piston needs to be able to easily glide or you could be getting a pad that's dragging more than it should.

 

[cruizin01]

Not saying its your issue, just food for thought. We run a 5 series in chumpcar, our typical racqe is 14 hour and have run upto 24 hour. So driving a big, heavy and pretty fast car has required us to be very brake savy.

Personally I tend to treat rotors as a freq. disposable item. They get 4-6days of HPDE then they have tons of heat stress cracks and I toss them. Also, if you track a lot, when did you last rebuild your calipers? The piston needs to be able to easily glide or you could be getting a pad that's dragging more than it should.

No I understand, I appreciate the opinions.

If I was running $100 rotors I would treat them as disposable too. But these ones aren't. I was at least trying to get my monies worth. I dont even think I had one track day on them. Last year I just had too many things going on.

Ill check the calipers out. Seeming as they both do the exact same thing on both sides Im not inclined to think they are both dragging similar, but its possible.

 

[miamirice]

No I understand, I appreciate the opinions.

If I was running $100 rotors I would treat them as disposable too. But these ones aren't. I was at least trying to get my monies worth. I dont even think I had one track day on them. Last year I just had too many things going on.

Ill check the calipers out. Seeming as they both do the exact same thing on both sides Im not inclined to think they are both dragging similar, but its possible.

Yep, I agree. Mine are a whopping $59 each. They ship in those flat rate post office box. My mailman hates me LOL.

 

[bostonaudi]

Fit under my 17x8 Enkei PF01's nicely:

Rear R32 brakes actually a little tighter: