S3 rear brake upgrade

[Goubo1]

Looking to upgrade there brake set up I seen this set up and would fill the rear wheel nice too

Anyone know of any other kits that are available and has anyone fitted a kit like this ? If so would you recommend it ?


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[snowy]

Compbrake, I use that setup

You get a caliper spacer, bell and rotor

The caliper spacer is very simple. The bells ok too.

I wouldn't touch compbrake rotors though -they crack up under heat (I use AP rotors - 330x20mm is a readily available rotor size)

You used to able to buy the spacers and the bells from compbrake as spare parts, then match to someone elses rotors

 

[Goubo1]

Thanks for the heads up mate is there any other sort of off the shelf kits available??

 

[snowy]

none that I personally know of

I've seen some Tarox stuff in general (not tested) and it looked good quality, but not specifically their rear kit (300x20mm)

 

[<tuffty/>]

Bill and I have plans to put a kit together... bells, rotors and brackets on OE calipers... just not had the time..

<tuffty/>

 

[badger5]

we may get a chance to look at this soon... more hands and all that

 

[Goubo1]

Well keep me posted guys I'll definitely have a kit

 

[Darrell]

Tufty, to equal out the 6 pots on the front of mine I was thinking of using rs4 master cylinder, 25.4 if it fits?? rs4 rear calipers and whatever discs required to make them work. What's your opinion?

 

[desertstorm]

I did a lot of research on the net and couldn't find anybody that had found a straightforward Master cylinder upgrade for the S3 /TT.
I tackled the rear brake upgrade by fitting Calipers with a larger piston.I had fitted some TRRS 4 pot Brembo's with 334mm V6 brake discs on the front and found the car was standing on it's nose when braking hard.
The standard rear brakes don't get that much abuse really and having such large discs on the rear isn't required from a heat capacity point of view. You are just moving the caliper out to gain the mechanical advantage 330/256 = 1.29 so about 30% extra braking torque.

https://www.audi-sport.net/xf/threa...ar-g25-660-upgrade.319422/page-4#post-3255700

I fitted rear calipers off an A6 4.2 V8. These are pretty much identical to the standard caliper but have a 43mm piston instead of a 38mm one.
(43x43) / (38x38) = 1.28 so pretty much the same braking force as fitting a 330mm rear disc with a standard caliper.
This restored the braking balance to the car, no longer stands on it's nose when braking hard and seems to work well on the track. I didn't have excessive pedal travel before doing this upgrade, and I know some of the multi pot front brake upgrades can leave you with a lot of pedal travel. Fitting these rear calipers made little difference to the pedal travel on mine.
You don't get to have larger rear discs in the back but you can use standard discs and you get new rear calipers which you may be buying anyway as the existing ones are likely not to be the best.

 

[Darrell]

Yes I have done loads of research and found nothing, that's why I started looking for larger master cylinders. Now need to find someone breaking both cars and find out if they are interchangeable

 

[Tj 0785]

I’ve seen the transporter t4 master cylinder mentioned before as an upgrade not sure if it works though or if it was on here or not

 

[<tuffty/>]

I’ve seen the transporter t4 master cylinder mentioned before as an upgrade not sure if it works though or if it was on here or not

ESP would be an issue I believe... don't know if there is an ESP compatible variant...

<tuffty/>

 

[badger5]

I did a lot of research on the net and couldn't find anybody that had found a straightforward Master cylinder upgrade for the S3 /TT.
I tackled the rear brake upgrade by fitting Calipers with a larger piston.I had fitted some TRRS 4 pot Brembo's with 334mm V6 brake discs on the front and found the car was standing on it's nose when braking hard.
The standard rear brakes don't get that much abuse really and having such large discs on the rear isn't required from a heat capacity point of view. You are just moving the caliper out to gain the mechanical advantage 330/256 = 1.29 so about 30% extra braking torque.

https://www.audi-sport.net/xf/threa...ar-g25-660-upgrade.319422/page-4#post-3255700

I fitted rear calipers off an A6 4.2 V8. These are pretty much identical to the standard caliper but have a 43mm piston instead of a 38mm one.
(43x43) / (38x38) = 1.28 so pretty much the same braking force as fitting a 330mm rear disc with a standard caliper.
This restored the braking balance to the car, no longer stands on it's nose when braking hard and seems to work well on the track. I didn't have excessive pedal travel before doing this upgrade, and I know some of the multi pot front brake upgrades can leave you with a lot of pedal travel. Fitting these rear calipers made little difference to the pedal travel on mine.
You don't get to have larger rear discs in the back but you can use standard discs and you get new rear calipers which you may be buying anyway as the existing ones are likely not to be the best.

are you saying the A6 V8 rear calipers on std 256mm rears "felt" like 330mm front? or have I misunderstood it?

 

[desertstorm]

are you saying the A6 V8 rear calipers on std 256mm rears "felt" like 330mm front? or have I misunderstood it?

What I was trying to say is that fitting a rear caliper with a larger piston on a standard size disc has the same effect as fitting a standard size caliper on a larger disc. A lot of the rear brake upgrades involve spacing out the standard calipers and using larger discs. To get the same braking force using a standard size caliper would need a 330mm rear disc.
There is no need for such a large rear disc from the point of view of heat dissipation. The rear caliper has small pads and rear brakes only account for around 25-30% of the braking.
I had to do something with the brake balance on the TT as when I fitted the TTRS calipers with 334mm V6 discs the car was standing on it's nose when braking heavily. Even when braking more normally the difference in performance between the standard brakes and the Brembos was very noticeable. By fitting these calipers and keeping the original 256mm discs the braking is much more stable and flat .

 

[hharry100]

Need a set of rear discs also and may aswell get uprated if available
Any date for when these maybe available?

 

[hharry100]

May go the larger rear caliper piston route if there no easy and cost effective way to have larger rear discs and spacer for the original rear caliper.
What are the part numbers for the A6 4.2l V8 rear calpers and are they easy to find?