Well, some time ago I started to think about a way of upgrading the rear brakes on the Coupe without having to go to the expense of the Tarox kit (approx. £500 !). The idea was to use a replacement caliper that would accommodate a slightly larger (257mm) vented disc for better cooling and general stopping power. JohnS kindly lent me a set of calipers from a Skoda vRS that were designed to work with a 22mm thick disc and had the same mounting arrangements as the standard Coupe item. Today, I finally found the time to offer them up and see what will need to be modified to fit them .

Before I started, I must confess that I had some concerns, as the vRS caliper has a totally different offset on the slider that the Coupe one (see Photo 1 ). This meant that I was going to have problems with the offset of the disc (although not impossible to fix). Unfortunately, the next stage identified a much bigger problem, the vRS slider is a lot thicker than the standard, meaning that there is no way that it will fit onto the hub barrier (see Photo 2 , Photo 3 , & Photo 4 ). Bu**er !

Not to be defeated so easily, I then had a look at the option of removing the vRS slider and went back to the standard Coupe one, which at least bolts onto the hub. Now, I have the later alloy calipers on my car, which have a bar across the front of the slider. This stopped me fitting the caliper properly, but with the older style slider (that have no such bar) it would be possible to fit the larger vRS caliper onto the slider without a problem (see Photo 5 ). I even put this arrangement onto the car and fitted the wheel to check clearance. No problem, even with the caliper sticking out a little due to the bar, as shown in Photo 6 ) .

Now, the biggest problem that remains is that it is obviously not possible to use the Coupe slider (designed for 10mm discs) with 22mm ones ! The way I see it, there are two options to solve this:

1) Widen the gap to accommodate a thicker disc in the standard slider.
Pros - Relatively easy to do, and it fits! Punto 16v disc should be available off the shelf to fit with the correct offsets
Cons - Not sure that there is enough space on the slider to allow enough meat to be removed and still retain space for the pads

2) Find a different slider that will fit onto the Coupe hub carrier and also take the vRS caliper.
Pros - Saves hacking a slider up to fit the thicker disc; a better engineering solution.
Cons - Finding the perfect slider

Other issues that still need sorting include handbrake cable (I have an idea about this ) and flexible brake hose, but I can't really look into these until I have at least fitted the caliper correctly onto the hub, so they will have to wait for a little while. Hopefully Carl is going to help me out by providing a set of the older steel calipers with slider without the bar.

If I manage to resolve these issues, I am hopeful that this will be a much cheaper upgrade than the Tarox kit. The calipers are available second hand, but they are only about £90 new, and the discs are only around £25 for standard ones (upgrade ones should also hopefully be available for a little more, depending upon exactly which one I end up having to buy). I guess they may be a need for a couple of hoses as well, but that should still see it coming in at less than half the price of the Tarox. Obviously, performance gains may not be as great but for track abuse, when brake cooling is actually more important, I think it should be a good improvement .

I'll keep you posted on further progress, but if anyone has any comments or suggestions, please feel free to chip in .

Phil

nice work Phil!

sometime ago I heard that someone was considering/trying out maybe even an audi A3 rear brake conversion. Is that the same as the VRS you're trying or something completely different?
I'll ask him and comeback to you if he's had any success

cheers

V.

Good work Phil and thinking outside of the box is why British engineers have pioneered so many things.

Good work Phil.

Mark

Just a thought, could something from the Alfa range be a closer match?

I think the Alfa GT has better rear brakes(vented), not sure of the fitment though. But the majority of the Alfa range already has the same or worse rear brakes than the 20VT.

Mark

Cant you just trim down the skoda calipers so they fit on the hub? Come on, an engineering solution isn't an engineering solution unless there's an angle grinder involved!

Well the Skoda slider is 20mm thick with an angle, and the Coupe one is 10mm and straight, so I don't think it would be much use anyway .

Phil

But all you need to clear is the abs ring which I reckon you would anyways. Grind it from the back down to the max thickness you could get away with and I reckon it'd fit.

Whether or not all that heat might be bad for the metal I dont know, but I just like playing with my angle grinder....

Would it be very costly to make up/maufacture that part of the brake bracket through?! Not sure about that sort of thing.

I'm sure alot of people would go for it as an upgrade if a group buy was on the cards!! Just using the piston part of the caliper from the Audi/VW/Skodas for the top part?!

Mark

mattB - I know what you mean, but the angle in the slider is also going to be a problem, as it will move the disc position quite a way forward. It's not possible to space it, as this will only make the offset worse .

Mark - The bracket is quite a specialist bit of kit, as it houses the slider bolts as well. I guess that it could be manufactured, but at quite a cost I would imagine .

Phil

Well, if only you were one of these types that was into the group buys. Then you'd have the big brake rear kit already.

Phil - would it really be that difficult to make up a kit like the tarox one?

http://www.gazzella.cc/cart.php?tar...amp;product_id=17615&category_id=724

The brackets don't look 'that' special (or do you mean the bracket on the caliper?)

Matt - I know, I know! The one group buy I decided not to join in with to save a bit of money, and I've been kicking myself ever since .

Ken - Sorry, I mean the slider itself, which is what I thought Mark was referring to .

Phil

Well if you need to have a snoop around a Tarox big rear brake kit, i'm happy to whip a wheel/bracket off at the SE meet as MattB and his angle grinder won't be about.

the GT has solid discs, i've started a topic about it a while ago. the only italian donor is the brera, which has vented rear brakes...

The setup i went for are alfa GT rear brakes (mind you, 5 bolt hub) and lancia thema rear calipers (bigger piston) + adjustable brake compensator. Front are alfa GTA calipers and discs with decent pads, brake fluid and cooling ducts. Also got rid of the rear brake shields.

I must say it's working rather well, altough, lately, i tend to keep the foot on the accelerator pedal rather than braking.

Going the Alfa route means switching to 5 stud, which I don't want to do, as I like the standard 20VT alloys . There are options in the Fiat range, but more from the smaller car range front discs. Once I have the caliper sorted, the hunt for a disc will begin !

Dink, do you have any photos of the cooling ducts? I was considering this for the fronts, but hadn't gotten round to thinking about how they terminate at the discs to get the maximum cooling effect.

Phil

Sorry, it was your post I was remembering, but obviously badly!! I thought it was the GT, but obviously the Brera.

Cheers,

Mark

Found these on the Wilwood website

http://www.wilwood.com/Products/001-Calipers/033-cpb/index.asp

Phil,

I've just sent hubs to these chaps to do a brake kit for me:

http://www.compbrake.co.uk/

I've scrapped what I was doing with AP / BG developments as they were useless.

They will be working with 17 inch team dynamics wheels for me - but if you wanted to send them one of your spare standard alloys they might be able to do a rear brake kit to fit, and be interested in a group buy. They also do calipers to include the handbrake cable - AP dont.

Chap there i've been speaking to is Steve.

Given the front biased weight distribution of the coupe, is improving the rear brakes actualy going to help?

We'll find out soon enough! Put it this way - I changed the rear pads to Textar ones and the rear felt much more planted when standing on the brakes.

I changed my F&R discs (3G) and pads (textar) last year and the rear discs now have a lip on them and the discs look more used than the fronts. I noticed the difference in braking instantly on the back with this set up.

Edit just to add it's still not a good set up but I did notice an improvment in the rear braking.

A lot of people say the rear feels more planted with an upgraded brake setup. I wonder if this is due to the trailing arm setup on the coupe meaning the back will sit lower the more brake force is applied...

Also wonder is this gives a false sense of security if you need to brake mid corner, because the more brake force is applied, the less lateral grip there will be.

Could be completly wrong here but just some thoughts..

Erm... I dont think so. Put it this way - 100 mph and stand on the brakes and even a slight bit of lock and the back threatens to have a paddy.

Nice work ! I do think the solution might be a custom slider if we can't find one that fits the std caliper. If you give me dimensions between slider mounts I could ask around as I know a couple of people who own scrappies. I wonder if there is a a lucus/girling catalogue which describes them?

I've now got a few more old brake bits to play with (thanks CarlT ), so I'll try to have a play around with the sliders to get something to fit a little better. I think I'll try to bodge something together that will fit, and then take the dimensions off it. That way I can either search for something that matches on an existing set up (I may drop you a PM John ) or see about getting a custom one made up.

All I need to do now is find some time and decent weather to get on with it !

Si - I may go down the same route as you, but am still keen to get a low cost solution sorted out, if at all possible.

Phil

On that compbrake website the bell designer is a good idea!

http://www.compbrake.co.uk/bell%20&%20rotor%20dims.pdf

They seem to be doing a great job so far:

It's coming along Nicely:

http://i11.photobucket.com/albums/a198/suba11/DSCN3693.jpg

http://i11.photobucket.com/albums/a198/suba11/DSCN3692.jpg

http://i11.photobucket.com/albums/a198/suba11/DSCN3691.jpg

Calipers are off the new Audi TT....
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They look great. I'm 100% in the market for big rear brakes so I'm keeping an eye on both of these posts. BUT unfortunately there's a lot of talk about "this fits that" and "that's of the ..." and I'm a bit of a novice with development talk so Suba could you tell me what you have there. I mean what are the braking benefits of the TT calipers, is there a measurement of how much force the TT callipers put on the pads compared to the 20vt calipers or are we just changing the caliper so we can fit bigger discs? And what discs and size you have?