S2 Front Brake upgrade confusion

[Le S2 Audi]

With the help of Dave(quattroboy) i have recently machined some custom brackets for the 986 calipers to fit daves Ur, using 300 discs and to fit under his 15" wheels.

Dave will have these at the weekend and once he has them fitted and tested i will be manufacturing a few sets for stock.

If anyone buys these calipers,please give me a shout if you need any brackets.

Cheers

Kev

As Posted By Bambridge in another thread!!

[Le S2 Audi]

The reason for using 996/Boxster S calipers is that you can use the 30mm A8 brake discs. If you use these Boxster calipers you've got to find thinner discs with the right hat height and PCD for 5 studs - that could be hard...........
and once you've done that you end up with thin discs with less thermal inertia putting you back in the realm of standard S2 discs so you're not going to gain anything.

Since 996/Boxster S calipers fit fine under 16" Avus wheels with standard RS2 brackets why bother

John

Cheers John,

I was just asking the question... As they seem very similar in size....

Thanks for the info!!!

K..

[martinjs]

As Posted By Bambridge in another thread!!

How thick are these 300mm disks he is using and what car are they from?

What are the diameters of the pistons on the 996/boxster s front vs rear vs these 986 calipers?

[bambridge]

[QUOTE=martinjs;447226]How thick are these 300mm disks he is using and what car are they from?

The discs are 25mm thk and the set up is for his urquattro!

[Le S2 Audi]

What are the diameters of the pistons on the 996/boxster s front vs rear vs these 986 calipers?

996 Front Caliper Pistons are 36 & 40mm.

996 Rear Caliper Pistons are 28mm Each

986 Front Caliper Pistons are 30 & 34mm.

986 Rear Pistons I dont Know.... I have not had a set to measure...

[philKS2]

THIS IS A SUMMARY OF MY BRAKE UPGRADE DECEMBER 2009

Audi S2 brake upgrade using Porsche 996 callipers

AIM: A bolt-on* upgrade to the front brakes on a 1994 Audi S2 ABY, fitted with original 16 inch Avus 6-spoke wheels.
(*some Forum users have done upgrades involving machining discs, callipers etc to get a fit. I wanted something any competent mechanic could do with bought-in parts)
WHY UPGRADE? It’s generally agreed the stock brakes are not adequate for the weight and power of this car, esp if it’s been chipped

PROJECT
After much reading and help from S2Forum members and my local mechanics, I decided to follow the route of fitting Porsche 996 brake callipers (they have FOUR pots or plungers compared to the original Audi callipers TWO).
I also went for the 314mm Audi A8 discs, which are larger than the stock parts, and so offer a greater leverage diameter for braking.

ISSUES :
1- callipers – would the Porsche callipers fit under the 16 inch wheels?
2- discs – which discs would fit under the 16 inch wheels?
3- fitting – the Porsche callipers need to be fitted on a non-standard bracket to ensure correct positioning over the disc.
4- the Porsche callipers would be second hand from a breaker, on the basis that I can’t afford new, and 2001 callipers will still be much younger than the rest of the car!

Also – I decided to buy Brembo discs, as one of my previous cheap ones had warped, and I went to Textar pads, since these are the ones Porsche use with the 996 callipers.

NOTE ON COST :
1- PARTS – prices can vary of course, and you might be luckier than me with the second hand callipers. However mine were in excellent condition (complete with old Textar pads but I did not want to re-use them), and did not need any refurb or extra parts.. some may need new damping plates, new fixing bolts etc)
2- LABOUR – Approx 3.5 hours at £40 /hour plus VAT to get parts fitted by brilliant local mechanics.


PARTS


DISCS
2x Brembo vented brake discs. For a 2.8litre 1996 Audi A8 314mm x 30mm
(CPS describe them as 09.7728.11 Brembo disc set)
Competition Braking Supplies 01748 831 200 WWW.racepads.co.uk
£113.55+vat + £10 delivery TOTAL £142.08

CALIPERS
1X Porsche 996, brake callipers LEFT 996 351 425 01 = Porsche Carrera L/H Front Black
1X Porsche 996 brake callipers RIGHT 996 351 426 01 = Porsche Carrera R/H Front Black

Douglas Valley Breakers, Lancs. 01257 472866 www.douglasvalleybreakers.co.uk
(helpful, some negotiation on price, parts in excellent order as promised)
£186.88 each + vat + delivery TOTAL £391.01

PADS
Set Textar brake pads Textar T4045FE Porsche part no; 996.352.940.0
23329 170 319
Europarts 0870 150 6506 Not very helpful and no knowledge at all
£5.00 + vat and delivery TOTAL £84

BRACKETS
2x bracket and bolts “slimline” ones specifically for 16 inch wheel
Kev aka Bambridge on www.s2forum.com Kev's website: www.kdr-engineering.co.uk
TOTAL £110 inc postage

BRAKE FLUID TOTAL £6

TOTAL PARTS £733.09


LABOUR
Andy at R&D Autos, Bristol 0117 924 0364 – used to race cars, former Audi Quattro owner, very helpful.
3.5 hours £140 +vat TOTAL £161.00


GRAND TOTAL £894.09


NOTES
Buying callipers:
Try www.ebay.com for American dealers, but remember shipping will be £50, or use parts gateway (http://www.partsgateway.co.uk), or search for a Porsche breaker.
The car is sometimes listed as a Porsche 911-996 2001 model
996 351 425 01 = Carrera L/H Front Black
996 351 426 01 = Carrera R/H Front Black
996 351 425 11 = Boxster S L/H Front Red
996 351 426 11 = Boxster S R/H Front Red
I thing the first three digits are the model, next three are position (front/rear), next three are the fitment (l/h r/h), last two colour. Red tend to be more expensive.
Don’t buy rears by mistake – they will use 352 rather than 351.



CONCLUSIONS

1- CLEARANCE – Kev (Bambridge) supplied me with some disc spacers and longer bolts in case I needed to push the wheels out further to allow clearance for the callipers. This was NOT necessary, as the callipers fit with a good 5-6mm clearance from the inside of the wheel.

2- HOSES – my original flexi hoses were fine (from bulk head to strut) and my mechanics made up a pair of “hardline’ (ie not flexi) hoses from the strut to calliper. If you need hoses, you can get them made by Merlin Motorsport at Castle Coombe 01249–782101. Hardlines are used in the RS2, and should have enough flexibility to move aside when discs need changing, and don’t need to move for new pads.

OTHER OPTIONS
Bigger wheels – some peeps have fitted bigger 18 inch replica Avus wheels, which enable them to use Porsche Big Red six-pot callipers, and 323mm Audi A8 discs … these would NOT fit under the 16 inch wheels. New wheels and tyres could set you back £800+

NOTE from Kev (Aka Bambridge) after some practical experiments with various wheels and callipers:
Avus 16" Alloys with standard 996.351.425/426 callipers & 314mm discs WILL fit, when used with Kev's NEW "Slimline" Mounts/Bracket

Avus 16" Alloys with standard 996.351.425/426 callipers & 323mm discs WILL NOT fit, when used with a RS2 or Kev's "Standard" Mounts/Bracket Even with a 15mm spacer (which give's you an extra 2.5mm clearance due to the wheel taper)... 16in Avus with 323mm disks and 996.351.425 callipers with 15mm spacers actually scratch the inside of the wheel...


CREDITS
This summary has drawn on material across www.s2forum.com, and www.S2central.net with input from numerous people who have done similar upgrades, and especially Kev (Bambridge).
Also the co-operation of a good garage (R&D Autos, Bristol) meant I knew the work would be done well.

Phil Dec 2009

[Rusty]

£900 Glad it's all sorted Phil.

[quattrostyle]

that's some serious money, hope it's all worth it.

Good write up.

[mouse]

Good to get confirmation that spacers are not required with Kev's slimline brackets.

[mouse]

I had the 996 calipers installed with Bambridge's slimline brackets and 314mm discs a couple of weeks ago and it all fit together beautifully under the stock 16" avus rims, didn't even have to remove the wheel balancing weights from inside the rims which I thought I'd have to do for clearance but my weights were close enough to the outside of the rim they they didn't interfere.

[bambridge]

I had the 996 calipers installed with Bambridge's slimline brackets and 314mm discs a couple of weeks ago and it all fit together beautifully under the stock 16" avus rims, didn't even have to remove the wheel balancing weights from inside the rims which I thought I'd have to do for clearance but my weights were close enough to the outside of the rim they they didn't interfere.

Many Thanks for the order!

[19852316]

slimline brackets for Boxster S calipers?

Does this thread refer to someone that is making adaptor brackets for mounting Boxster S calipers to Audi's? I've got a 1995 S6 and just bought a BIRA system 3 setup with the Boxster S calipers. There is some new discussion recently that the BIRA caliper brackets may be susceptible to failure. I'm not sure how many other reliable alternatives exist here in the states anymore, seems many users are experiencing bracket failure in many of the most reliable suppliers we've all used. Does anyone in the UK know of a better solution?

regards,
patrick
milwaukee, wisconsin

[bambridge]

Does this thread refer to someone that is making adaptor brackets for mounting Boxster S calipers to Audi's? I've got a 1995 S6 and just bought a BIRA system 3 setup with the Boxster S calipers. There is some new discussion recently that the BIRA caliper brackets may be susceptible to failure. I'm not sure how many other reliable alternatives exist here in the states anymore, seems many users are experiencing bracket failure in many of the most reliable suppliers we've all used. Does anyone in the UK know of a better solution?

regards,
patrick
milwaukee, wisconsin

Caliper Bracket Failure??

More info please!!

[Le S2 Audi]

Does this thread refer to someone that is making adaptor brackets for mounting Boxster S calipers to Audi's? I've got a 1995 S6 and just bought a BIRA system 3 setup with the Boxster S calipers. There is some new discussion recently that the BIRA caliper brackets may be susceptible to failure. I'm not sure how many other reliable alternatives exist here in the states anymore, seems many users are experiencing bracket failure in many of the most reliable suppliers we've all used. Does anyone in the UK know of a better solution?

regards,
patrick
milwaukee, wisconsin

Hi Patrick,

Yes it does... See the guy who posted before you (Bambridge) as he does a range of Brackets...

I have a set fitted to my S2 with the 996 Calipers... & am very pleased with them...

Cheers

K.

[19852316]

possible BIRA bracket failure issue

Gents, here is what I found this morning. I am concerned enough to reach out to others now and find an alternative to the brackets that came with my brake setup I just purchased. They're used brackets so I have reason for caution. Bambridge, please provide me with more information about your brackets offline or provide a link back. I'm open to recommendations and hearing others' experiences with brackets, both good and bad.....so can I presume that if a bracket works to adapt your car to use this boxster S caliper of mine that it will fit my chassis as well? I'm hoping for something that will allow me to use my stock 16" Avus with 35mm offset.

best regards