# Possible rear vented rotor combinations for the Coupe



## 90quattrocoupe (Feb 7, 2002)

Below you will see two possible ideas for rear vented rotors. I tried a couple of different calipers and rotors, basically running with ideas I got from other original thinkers on other forums.
These are a couple of different combinations using two different rotors, two different calipers, both off the same carrier. The rotors are both 280X22mm. The g60 rotor weighs 11lbs and the New Beetle weighs 13 lbs. It is now 2010. Another option is a B6 S4 rear rotor. It is 300X22, but you can have it turned down to 280, and use the shims the same as the New Beetle rotor.








These are the two rotors I used. CorradoG60 and a New Beetle. For the peoples in the old countries, all the G60 rotors should be the same as the Corrado. This was the only G60 imported to the states. The New Beetle rotor is the same as the A3, which we haven't gotten either.
Both rotors have had the center bore increased from 65mm to 68mm. The G60 rotor was redrilled from 4X100 to 5X112. The NewBeetle/A3 was slotted from 5X100 to 5X112.








I used the Corrado for the setup pictures. This is the aluminum A8 caliper on an S8 Carrier. This allows for the 280X22 vs the 269X22 on the normal A8. This caliper weighs slightly over 3lbs.








I got this idea from Stick Insect(David) on the S2forum. He mentioned using an easier to find caliper than the A8. I happened to have an S6 Rear caliper lying around, and fit it up to the S8 carrier. It fits just like the A8. It may be easier to use the parking brake cable on the this caliper as it is in the same place as the coupe rear. The A8 caliper has the parking brake mechanism in a slightly different location, but it stills pulls from the side and not the front. The S6 caliper weighs in at 6 lbs, but is definitely more available from a wrecker than the A8 caliper is.








This is the G60 rotor with just the S8 carrier.








As you can see from this picture, the G60 rotor comes a little close to the inboard edge of the carrier. It was even closer before I took the next step.








I took a look at the carrier and noticed that they had excess material on the inboard edge from the bolt on area. The least amount of excess material was 1.5mm. So I had an additional 1.3mm milled off each of the carriers. This allowed breathing room for the G60 rotor.








This picture shows the gap between the S8 carrier and the bolted up A3/New Beetle rotor. It is more centered, but as others did on this forum, you need to use 2mm spacers when bolting up the S8 brake carrier to the rear hub carrier. This moves the carrier outboard.
Now the brake carrier is bolted to the outside of the hub carrier, and not the inside like the coupe. Luckily for us the brake carrier is machined on both side of the mounting holes, just as the hub carrier is.
I am going to use the G60 rotor with the A8 carrier, and when they wear out, I will use the New Beetle rotor.
Remember, if you end up trying one of these combinations, the A8 caliper or the S6 caliper, they are used on the opposite side of the car, from where they were normally used. The right caliper goes on the left side of the Coupe and the left caliper goes on the right side of the coupe.
As an update to that thread, the B6 S4 rotor, which is 300X22 has the same offset as the New Beetle rotor. So instead of having the bolt holes redrilled and the center hole rebored, all you have to do is have the rotor turned down from 300 to 280 and you are set. Paul(S2central.net) on the S2forum just recently did this, and it came out great.
One thing about using hubcarrier and hubs from a Euro coupe on a states coupe. You have to watch what year you get them from. Up to 1992, the struts and carriers used 12mm bolts. After 1992, the hubcarriers bolted to the struts using 14mm bolts. I did not realize this until I received the hubcarriers from the UK. The ones I bought came off a 95' coupe, and were 14mm. I thought I was screwed, but being a backyard mechanic from way back, I just reamed out the strut holes to 14.3mm. The center lines were the same, just the holes were larger on the hubcarriers. 
I used these to ream them out:








There are available from McMasterCarr.
Greg




_Modified by 90quattrocoupe at 11:07 PM 4/29/2009_


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## billzcat1 (Sep 10, 2001)

*Re: Possible rear vented rotor combinations for the Coupe (90quattrocoupe)*

Interesting. I wonder my my setup using S8 Carriers/ S6 rotors is best suited for the NB disc but turned down in OD to 273mm? On my setup, the extra 3.5mm (radius) was wasted rotor area not in contact with the pads. 
Also, I didn't have to do any machining of the caliper carrier.


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## 90quattrocoupe (Feb 7, 2002)

*Re: Possible rear vented rotor combinations for the Coupe (billzcat1)*


_Quote, originally posted by *billzcat1* »_Interesting. I wonder my my setup using S8 Carriers/ S6 rotors is best suited for the NB disc but turned down in OD to 273mm? On my setup, the extra 3.5mm (radius) was wasted rotor area not in contact with the pads. 
Also, I didn't have to do any machining of the caliper carrier.









Richard,
This set up has the opposite effect. The inner part of the rotor is not under the pad. I was going to try different pad to see if I could find a stock configuration that covered more of the rotor.
The carrier was only machined for the G60 rotor. A little close on the inside. The New Beetle would have cleared without the machining.
What caliper are you running with that set up?
I found a rotor that had an hat size between the two rotors, but you can't get a Rover 75 rotor in the states. I believe it would have fit. The only maching would have been to the rotor itself. Larger center bore and slot the lug holes.
Greg


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## billzcat1 (Sep 10, 2001)

*Re: Possible rear vented rotor combinations for the Coupe (90quattrocoupe)*

I am using the rear calipers from Ur-S4 and S8 carriers for my setup. Perhaps I was sent the 269x22 carriers not the 280x22 carriers. This would make the most sense as this was one of the few times I went to the dealer without a part number in hand.


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## 90quattrocoupe (Feb 7, 2002)

*Re: Possible rear vented rotor combinations for the Coupe (billzcat1)*

Richard,
I would say you got the wrong carriers. As you can see by the picture, the UrS6 caliper with the S8 rotor fits a 280X22 rotor with no height problem at all. 
Greg


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## billzcat1 (Sep 10, 2001)

*Re: Possible rear vented rotor combinations for the Coupe (90quattrocoupe)*

I am sure this is what happened. Can you give me the part numbers for your caliper carriers so that I can rectify this issue?


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## 90quattrocoupe (Feb 7, 2002)

*Re: Possible rear vented rotor combinations for the Coupe (billzcat1)*


_Quote, originally posted by *billzcat1* »_I am sure this is what happened. Can you give me the part numbers for your caliper carriers so that I can rectify this issue?

Richard,
There is no part number on the Carrier. The part number I have on the receipt is 4D0-615-425C. This matches the family album for the S8 carrier.
Greg


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## 90quattrocoupe (Feb 7, 2002)

*Re: Possible rear vented rotor combinations for the Coupe (90quattrocoupe)*

updated


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## littlegreek (Nov 24, 2006)

*Re: Possible rear vented rotor combinations for the Coupe (90quattrocoupe)*

You got the pics back up? Very nice. I was going to update this with my set up or sticky a whole new thread.
Here is my set up:B5 1.8T rear hubs
B5 S4 carriers
B5 S4 rotors
Audi TT 225 calipers
Custom SS braid lines w/banjo bolt end
My set up needs no shimming of anything or bolt hole modification,as it just bolts up. I cannot take total credit for this as you and A_CQ(username) on motorgeek did most of the trailblazing.


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## 90quattrocoupe (Feb 7, 2002)

*Re: Possible rear vented rotor combinations for the Coupe (littlegreek)*

Yea, didn't realize that AOL had gotten out of the picture business, until someone wrote me an email, saying there were no pictures. So I had to find a new site and put it back together.
It has been on Audiworld in the tech section, too. One of the problems with VWVotex and Fourtitide, no picture hosting for FAQs. To much stuff lost over the years, as people move on.
Put your brake option up on here for sure. All possible options, give people more ideas of where to go. I got my ideas from a lot of different places, before I put it up here. Just wanted people to know.
Greg W.


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## MK1 Rabbit GTI (Jan 13, 2006)

will the B5 S4 carriers bolt up to the stock 90 rear hubs? or would you need the b5 hubs?


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## 90quattrocoupe (Feb 7, 2002)

MK1 Rabbit GTI said:


> will the B5 S4 carriers bolt up to the stock 90 rear hubs? or would you need the b4 hubs?


What year 90?

Greg W.


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## MK1 Rabbit GTI (Jan 13, 2006)

its a 1990, 90 quattro.

would urs4/6 rear brakes work?


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## Extreme90path (Jan 12, 2010)

Do you guys think this nice little set up would work out ok on a 5x112 converted 4kq?


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## 90quattrocoupe (Feb 7, 2002)

Extreme90path said:


> Do you guys think this nice little set up would work out ok on a 5x112 converted 4kq?


It all depends on what your struts are. I know for sure that if you are using, B3 struts with S2 hubs, then it will work. If you are using some other combo, you may have to come up with a rotor with a different offset. Ideal size rotor offset with this combo is, 39.5mm. The Corrado rotor is almost right on that size, and the New Beetle rotor is about 36.5mm, but that is why you need to shim the caliper if you are using that rotor.

Greg W.


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## Extreme90path (Jan 12, 2010)

Ok cool man. Thank you! I think I am going to play around with the one piece set up and see what I can work out.


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## CarverGeeker (Jun 12, 2011)

Two quick questions:

1) Would this work on a B3 80 quattro as well?

2) What about the front brakes? What carriers, calipers, and rotors would you recommend for upgrading the front brakes to 2-piston calipers on the 80q as well?


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## 90quattrocoupe (Feb 7, 2002)

This will work on an 80Q. 

Fronts. For a an 80Q you can use the G60 calipers from most any audi. You can't use the rotor from a 20V 90, or coupe/B4 as these all have the wrong offset. You need the 276X25 rotor from a 5000, 100 200. These have an offset for 46.5mm. The ones list above are more than this. You will have to redrill the rotors to 4X108.

Or if you can find a set of hub carriers from a B3 90 20V, you can use those, unless you have one piece struts.

Greg W.


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## Brendub (Mar 11, 2003)

*4x108 to 5x112 1991 Audi Coupe Quattro*

Hey guys, I know this is an old thread but I have a couple of questions for someone with some experience in converting from 4x108 hubs to 5x112. I have hubs from a URS6 which will work providing they are milled down 5mm on the back. My question is for the front rotors, URS4/URS6 rotors have basically the same specs as the CQ with just over 3mm taller top hat (59.7mm on the URS4/UrS6) than that of the CQ (56.3mm on the CQ). Is it possible to mill down the carrier the 3m difference to adapt these rotors to the Coupe? I want to keep the stock carriers in calipers rather than messing about with changing those also??

-Brendan


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## varia (Mar 21, 2009)

Brendub said:


> Hey guys, I know this is an old thread but I have a couple of questions for someone with some experience in converting from 4x108 hubs to 5x112. I have hubs from a URS6 which will work providing they are milled down 5mm on the back. My question is for the front rotors, URS4/URS6 rotors have basically the same specs as the CQ with just over 3mm taller top hat (59.7mm on the URS4/UrS6) than that of the CQ (56.3mm on the CQ). Is it possible to mill down the carrier the 3m difference to adapt these rotors to the Coupe? I want to keep the stock carriers in calipers rather than messing about with changing those also??
> 
> -Brendan


or you can use the stock CQ setup with 3mm spacer/washers


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## ebradley (Apr 14, 2018)

Saw a CLA55 AMG at pick n pull and saw its rear brakes and wanted to grab them just to try them on my b4


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