Our C4 UrS-cars came with Girling G60 brakes in North America. In Europe (and ROW), the early UrS4 came with the UFO brakes that North Americans saw on some Type 44 V8 cars. The later European and ROW UrS-cars came with a version of the four-pad HP-2 front brakes (similar to the B5 S4 2.7tt front brakes). For those with G60 brakes, you have a two piston calipers and 276 x 25 mm vented rotors, as shown here:



While adequate for North America highway driving speeds, the G60's were soon found to be less adequate when the car was tracked or driven in a spirited manner on the "twisties". Brake fade was the usual complaint. Back in the day (mid to late 1990's), there were several after market brake options, as outlined here in this archived page from Jimmy Pribble's UrS4.com (Click HERE)

If that got you all excited, slow down. Times change. BIRA is defunct. Mov'it and Stop Tech are still in business but when you check their websites, the don't seem to have anything listed for our cars (try if you want).

The current "school of thought" is we can do an front brake upgrade without needing either BIRA, Stop Tech or Mov'it using one of three options:

1. Using Porsche Brembo Big Red/Black (993tt/928GTS) calipers
2. Using Porsche Brembo Boxster (monobloc) calipers (like the BIRA Sys 1)
3. Using Porsche Brembo Boxster S/996 (Red) monobloc calipers (like the BIRA System 3)

THE PORSCHE BIG RED/BLACK OPTION

This is based on the use of RS2 brake brackets and Eur Audi A8 (323 x 30)rotors with four piston 993tt (Big Red) or 928GTS (Big Black) calipers. This set-up *just* fits under UrS4 Fuchs five spoke and UrS6 Avus 16" wheels (5 mm spacers help) as long as you watch where they put the weights during a wheel balance (in the wrong place, that minimal clearance will go to zero and the stick-on weight will be ripped off). The list of parts for this option includes (prices not necessarily current):

RS2 Brackets:
034 - OE RS2 Brackets = $229/pair (do not center caliper perfectly on rotor (1 mm issue))
034 - Shaved OE RS2 brackets to centre the calipers better =$295/pair
Apikol - Straight-up RS2 Clones = $219/pair (do not center the caliper perfectly on the rotor)
Apikol - Modified "RS2" Brackets = $239/pair (center the caliper perfectly on a 323 x 30 A8/S8 rotor)

Porsche 993tt "Big Red" Front Calipers:
993-351-425-10 (left), 993-351-426-10 (right) (tyically $200 more than Big Blacks - that red paint is *expensive*);>)

Porsche 928 GTS "Big Black" front calipers
Porsche P/N -928-351-423-03 L, 928-351-424-03 R
(Available from Apikol at $739/pair or try your friendly Porsche dealer or the like.)
NOTE: Because the 928 GTS calipers were originally mounted differently on the Porsche (trailing vs leading), for your Audi application, the x-over tube and bleeder screws on the 928GTS calipers must be swapped end-to-end so you end up with the bleeder screws on top.

44mm Damper Plates 965-351-096-00 $3.50 Qty - 4
36mm Damper Plates 964-351-096-01 $3.95 Qty - 4

Caliper to Bracket Bolts 999-067-041-09 $2.00 Qty - 4
(Note: Brendon at Apikol says "999 073 402 01 This is a torx head fastener. We previously used Pn- 999 067 041 01 but it got superseded - this was the 10mm allen head fastener." So YMMV

Bracket to Strut Bolts N 100 880 03 $2.00 Qty - 4
M12 x 1.5 x 25mm

Wear Sensors (x2)
993.612.368.00
OR
Wear Sensor holders (x2)
928.612.361.00

Brake lines (x2)
443 611 707 C (rubber OEM, M-F, 405 mm long)
Or custom stainless steel

Porterfield R4S pads $162.00

Later Audi A8 Rotors 323x30 4D0 615 301 J/BB $80.93 Qty - 2
(reference posting: CLICK HERE
And CLICK HERE TOO

Also, for the Movit or ECS people with the 2 piece rotors / custom hats, the replacement rotor ring is a Porsche 993tt 322x32, part numbers 993 351 045 10 (left) and 993 351 046 10 (right). Price is $225-$250 ea range.

THE BOXSTER BREMBO OPTION

This based on the original Boxster Brembo Monobloc four-piston calipers and the early A8 312 x 25 mm rotors. Fits under most 16" wheels. This was BIRA's first system, System 1. I was an early adopter (Brackets SN's 003 and 004) and have found them adequate for spirited driving, but have no track experience. The problem with BIRA was they never kept any stock and relied on 5 or more purchasers to want brackets at the same time. This was not a business plan.

Avalon Motorsports currently has an all-steel Boxster bracket, as shown here
034 Motorsports also has their version of an all Steel Boxster Bracket

Boxster Calipers - PN 986-351-421-03 (and -422-03) =$650 a pair from Apikol (Note: Stock Boxster Brembos are mounted differently (trailing vs leading), so for your Audi installation, the bleeders and cross-over tube need to be swapped end-to-end so the bleeders end up on top.)

Audi A8 312 x 25 rotors = 8E0615301R

THE BOXSTER S CALIPER OPTION

This is similar to the Boxster caliper option except that it uses the larger Boxster S (or 996 Carrera 2 or 4) front calipers over the larger Audi A8/S8 323 x 30 rotor. Note: This caliper is slightly taller than the Big Red/Blacks and will not fit under 16" wheels.

Calipers: Original 996-351-425 & 996-351-426 (from 996/911 Carrera 2 - Year 1994 - 2004, 996/911 Carrera 4 - Year 1994 - 2004, and 986 Boxster S - Year 2000-2004) (Note: Stock Boxster S Brembos are mounted differently (trailing vs leading), so for your Audi installation, the bleeders and cross-over tube need to be swapped end-to-end so the bleeders end up on top.)

Apikol has the brackets for this for $239
(Note: Brendon says "993tt" caliper - but this is wrong as the Boxster S equivalent - Brendon says he will change the webpage)

Later Audi A8 Rotors 323x30 4D0615301J

Hope this helps.