Big brake upgrade for 4-stud hubs

Posted: Sat Apr 10, 2010 7:07 pm

A project i've been working on over this winter...

After a few tip-offs and research I've found a reasonably cheap brake upgrade. The parts are based around the Ford Focus RS (1st gen) front discs that are 324mm x 28mm thick. These are as you can see 4 stud and being the older Focus come in a PCD of 108mm, same as the B3/B4 Audis.

The calipers I bought for around £220 from eBay, they were in very good condition and looked as though they had been refurbished at some point, they also came with a brand new set of Yellow-stuff pads. The calipers are Brembo 4 pots with a 44mm and 40mm sized pistons. These particular calipers came from a BMW 7 series V8. The real clincher was they also use a 324mm disc albeit 30mm width rather than 28mm but that's the only trade-off. The eBay seller bought these originally to go on his 3 series 330i but they weren't plug'n'play. I've painted them red with caliper high temperature enamel and put some new Brembo decals on to smarten them up.

The calipers obviously need mounting and after taking a few measurements I drew up a bracket design to mount them to the hubs. The material I bought off eBay for £20, it's bright mild steel. I am lucky to know a work colleague who has a small workshop in his garage and is quite handy on a mill and lathe as well as being an excellent welder, he welded my custom downpipes for the 30v transplant engine in the cabriolet. The brackets were machined and were a good fit.

I just had to file a section for them to clear the hub cylinder.

The brake discs also needed a visit to the lathe as the central mounting hole was too narrow to fit over the Audi hub mounting, just a few mm needed taking off.

The brake lines I had floating around and are Goodridge rear Audi coupe quattro lines ( S2/20v/2.8 ) and are just about the right length.

The extra four high tensile bolts are for mounting the calipers to the brackets.

In order to fit these I need to run 20mm wheel spacers for my alloy wheels to fit over the brakes, different wheels could possibly mean a lesser width spacer.

I've only trial mounted the brakes but due to running the spacers and 17 x 8" alloy wheels with 235 section tyres I've run into a temporary problem that the tyre contact area is just protruding beyond the wheel arch which is as far as I can tell an MOT failure item. It seems that the MOT criteria on this area which has been dictated by European law states that the wheel itself can protrude from the bodywork (wheel arch) by no more than 30mm but the tyre tread must be covered by the (wheelarch). I was thinking of maybe getting the arches rolled and flared but first I'll try some 215 section tyres and see if the tyre tread falls within the wheel arch. Cool

Posted: Mon Apr 12, 2010 8:57 pm

Nice work.
It's guys like you doing the hard work and posting on this forum that make things possible for a numbnut like me Laughing

I'm ok with any like for like swap anywhere on the car but my head always gets pickled with this kind of fancy stuff.

Michael

Posted: Mon Apr 12, 2010 9:01 pm

Great post this - well done sir! Very Happy

Posted: Tue Apr 13, 2010 6:21 pm

wopnderful, you alwasy make it look so as a matter of fact easy. enviable...

And how do they compare most importantly!

Posted: Wed Apr 14, 2010 9:20 am

I've not fitted them yet but as soon as I can get some narrower tyres swapped over to keep things legal and MOT proof I'll mount them up. Smile

Posted: Wed Apr 14, 2010 10:44 am

This is a great thread, thank you. Can you get some pics of the finished article and of how the wheels sit with the arches.

Nice work Exclamation

Posted: Wed Apr 14, 2010 3:33 pm

I will indeed be updating this thread as things progress. My wheels tend to stick out because of a number of factors such as alloy width (8"), tyre width (235/40 17) and design of alloy wheel, spokes that tend to bend outwards and more flush with the face of the rim would be better, as mine have a deeper dish they are not so easy to fit around the caliper, hence the 20mm spacer.

Needs to get out more Joined: Dec 29, 2007 Posts: 105

How did you get on with the tyres dude?

Posted: Thu Oct 28, 2010 10:00 pm

Brakes have been fitted a while now and WOW! Twisted Evil

I put on a set of 225 width tyres and I got a small amount of rubbing so had the arches rolled and inner plastic liners trimmed back, everything's good now Smile

.

Posted: Fri Oct 29, 2010 8:26 am

stops as well as it goes then?

Posted: Sat Oct 30, 2010 9:12 pm

Have the discs got a fairly low hat height that is pushing the caliper out?

Posted: Sun Oct 31, 2010 7:00 pm

Yes, the discs have a lower hat height plus my wheels have a deep rim that brings the spokes closer to the caliper.

Posted: Mon Nov 22, 2010 1:21 am

Nice one for this, might well look into this for my Turbo Cabby as i may need a brake upgrade with the WR in ! notworthy

Can i ask what offest wheels your using ?

Posted: Mon Nov 22, 2010 8:12 am

bumping this as well, fast would this clear an OEM 15in wheel or in theory would i need to go up a size?

Posted: Mon Nov 22, 2010 12:30 pm

I used the standard Audi offset of 35-37mm.

The brakes only just clear my 17" alloys Laughing

I will have to get some photos up. I was planning to take a step-by-step photo how-to but in the excitement I lobbed the brakes on and forgot! Rolling Eyes

They are nicely bedded in now and as well as looking the nuts the stopping power is immense, well compared to what I'm used to! Very Happy

Audi Nut Joined: Apr 21, 2012 Posts: 69

Would I be able to fit a set of these discs with a set of G60 calipers?

Posted: Thu May 03, 2012 11:24 pm

A bit late but do you have a pic of the finished article Embarassed

Thinking of having a go at this conversion, book marked your excellent write up for future consideration Cool

Posted: Tue Apr 23, 2013 5:31 pm

Any more info on this Si ?

Newbie Joined: Jun 11, 2013 Posts: 5

Perfect job.Thank you

Few questions:

1)Do u have a oem numbers of calipers and pads?
2)Do u sell calipers + brackets?
3) So i can used a Focus RS brake discs and BMW 7 V8 brake discs with redrill
4) Should your friend make another brackets?

Thanks lot

Posted: Sat Jun 15, 2013 4:55 pm

This was just a one off project, I don't sell or manufacture any parts. To be honest if you're looking for a brake upgrade it's a lot simpler to upgrade to five stud hubs and Porsche Brembo brakes, the parts are readily available and there are people who machine the brackets.

You can only use the Focus disks as they are 4-hole in the right PCD of 108mm.

Caliper part numbers and details can be found here:-

http://www.brakepartssuperstore.org.uk/contents/en-uk/d5103.html

Newbie Joined: Jun 11, 2013 Posts: 5

Please guy, do you have these measurments? Thank You

Newbie Joined: Jun 11, 2013 Posts: 5

This was just a one off project, I don't sell or manufacture any parts. To be honest if you're looking for a brake upgrade it's a lot simpler to upgrade to five stud hubs and Porsche Brembo brakes, the parts are readily available and there are people who machine the brackets.

You can only use the Focus disks as they are 4-hole in the right PCD of 108mm.

Caliper part numbers and details can be found here:-

http://www.brakepartssuperstore.org.uk/contents/en-uk/d5103.html

Newbie Joined: Aug 31, 2011 Posts: 7

Sorry to drag up an old thread, were dimensions for this bracket ever shared? It would be awesome if I could get these as I'm doing the same conversion! Would save a heck of a lot of trial and error!