C4 UrS Front Brake Options

[UrS4boy]

Based on trying to find something that would help Shone190 with his brake situation, I updated a previous C4 UrS brake option post that I had done at my home forum. I am posting the link below. I am also asking to be "schooled" on Girling brake designations, e.g. G54, G57 and G60. I know that G60s are two piston calipers (that's what Audi gave us in NAmerica for the UrS4/S6 instead of the HP2s that the rest of the world got). I think I have G57s (?) on my 98 C4 A6 Avant (single piston, solid rotor, but I am not sure). Any help as to what a G54 or G57 is will be appreciated.

Here is the C4 UrS4/S6 brake options link:

http://forums.quattroworld.com/s4s6/msgs/25331.phtml

[mcandmar]

G60's on an S4, they are just about able to cope with the weight of an S2!

Do you know how many variation of the front struts there are? Do the G60 cars use the same strut as a UFO or HP2 car? Basically what i am getting at is there an easy way to fit Porsche brakes to our UFO equipped S4 without having to change the struts.

[diesel des]

I made adapter carriers to fit Compbrake 4 pot Porsche copy calipers on urs4 struts. I'm using 345mm discs under 17 inch rims. Just clear and no more. Discs are less that 100 per pair and calipers with pads less than 300 new.

[UrS4boy]

C4 Wheel Bearing Housing info

G60's on an S4, they are just about able to cope with the weight of an S2! Do you know how many variation of the front struts there are? Do the G60 cars use the same strut as a UFO or HP2 car? Basically what i am getting at is there an easy way to fit Porsche brakes to our UFO equipped S4 without having to change the struts.

Ha. I did not realize that the S2s came with G60s. The North American UrS4/S6s were speed limited from the factory to 130 mph (208 kph) (10 minute job to remove the limiter) so I guess they figured G60's will do.

I have documented all the different wheel bearing housings (aka uprights, front struts, etc) in this post from the long version of the UrS Systems and Chassis "Map":

Wheel Bearing Housing 101:

http://forums.quattroworld.com/s4s6/msgs/33797.phtml

UrS System and Chassis Map - long manual version (links under diagram)

http://forums.quattroworld.com/s4s6/msgs/24724.phtml

Short active version (links *IN* the diagram, click on the label version):

http://members.shaw.ca/speedtek/UrS%20chassis%20Map.html

Apikol might make the caliper mount that you seek.

[mcandmar]

Ugh too many options. Either way it looks like custom brackets for whatever calipers i can get my hands on. Pity there isnt a cheap and easy easy bolt on solution.

[UrS4boy]

Ugh too many options. Either way it looks like custom brackets for whatever calipers i can get my hands on. Pity there isnt a cheap and easy easy bolt on solution.

There was a solution. BIRA had a UFO conversion bracket back in the day (circa 2000). BIRA is dead now.

[merlin's S4]

Somebody here documented drilling and tapping the ufo strut to take the HP2 caliper. If that works then I'm sure something could be done with the Cayenne caliper or perhaps with an RS2 bracket and 996 calipers ala the common S2 conversion.

[UrS4boy]

Somebody here documented drilling and tapping the ufo strut to take the HP2 caliper. If that works then I'm sure something could be done with the Cayenne caliper or perhaps with an RS2 bracket and 996 calipers ala the common S2 conversion.

I searched the forum on "UFO conversion" and pulled up a few threads. One with talk about replacing the UFOs with HP2s was posted by Craigs4 but there were no actual photos of the completed project. There was a correction on the rotor size (314 x 30, not 323 x 30):

http://www.s2forum.com/forum/showthread.php?t=38813&highlight=UFO+conversion

[saltinot]

Personally, I like this idea. HP2 to Cayenne

Fitted New Cayenne Calipers on UrS6

[UrS4boy]

Personally, I like this idea. HP2 to Cayenne
Fitted New Cayenne Calipers on UrS6

Yeh, that is why I included Pop's DIY in the revised C4 Brake options post yesterday.

http://forums.quattroworld.com/s4s6/msgs/25331.phtml

The major downside (IMO) of the Cayenne brake option is the need for 18" (or 19") wheels to fit over the caliper/rotor combination.

[popdemonic]

Cayenne 955 calipers is good to go with HP2 struts too.Everything is just bolt right up.They require the 350mm not 360mm rotors plus some metal bushings on the mounting bolts to align the caliper to sit at center of the rotor discs.All I need to do is grinding the rotor down to the matched size.
Write up will be posting soon once i finished everything.

[merlin's S4]

The major downside (IMO) of the Cayenne brake option is the need for 18" (or 19") wheels to fit over the caliper/rotor combination.

With the correct Cayenne/VAG caliper over a 330mm disc 17" alloys can be used.

[Hammu]

Cayenne 955 calipers is good to go with HP2 struts too.Everything is just bolt right up.They require the 350mm not 360mm rotors plus some metal bushings on the mounting bolts to align the caliper to sit at center of the rotor discs.All I need to do is grinding the rotor down to the matched size.
Write up will be posting soon once i finished everything.

What is the offset on your rotors?

[popdemonic]

What is the offset on your rotors?

overall height is 59,4mm,the stock 314X30mm rotor is 58,4mm. 1mm differences no big deal.

[rst]

I'm using VW Touareg 4 piston calipers.

http://forums.vwvortex.com/showthread.php?4598340-Touareg-Brake-Caliper-Questions

They fit PnP to UrS4/S6 without UFO calipers models. All you need is just (17 or 19mm long, dont remember anymore, it was two years ago) metal bush to center the caliper to the rotor. I'm using 323x30 or 323x32 A8/S8 rotors (dont remember this anymore either).