Rear brake disc options - new twist!

[Henka]

Well with a Caravelle disc I get the disc further in and 26mm thick - gain with 8E0 would be? I will be using Porsche/Brembo calipers rear, 4-pots.

[topsparky]

are you putting a seperate caliper in for the handbrake then henka???

[S2central.net]

Well with a Caravelle disc I get the disc further in and 26mm thick - gain with 8E0 would be? I will be using Porsche/Brembo calipers rear, 4-pots.

Ahh OK - with a 4-pot caliper at the rear you will have a better setup. Only thing I'd be concerned about is the disc being MUCH further in-board in case it fouls the hub carrier. Guess the 8E0 combination would be lighter than your suggestion but that is going to be lost in the noise I guess

Paul

[v8 coupe]

Alright all this talk of rear brakes and discs has my mind going. Here is my stage 2 kit I am building for my coupe. It\'s a 300mm by 22mm (11.75\" by .81\") wilwood straight vaned rotor. I got the hat for pocket change so a $35 is perfect for this. The carriers are s8 units as most are using calipers are g43\'s from a 200 20vt or t44 avant or V8q. The S8 carrier will clear this disc and the hats are perfect for the set up becuase the hat height from surface closest to rotor to top of hat on a 200 20vt rotor is ~27mm and my hats are 26.5mm so that means my rear rotors are going to be 300mm by 22mm by 48.5mm IIRC.

This is to go on a CQ and have a matching front rotor of 328mm by 28mm (12.90\" by 1.10\") with 996 rear calipers. This is to replace the current stage 1 kit of 996 rear calipers on 12.2\" by .81\" (310mm by 22mm) front rotors and 200 20vt rear rotors.

[Henka]

are you putting a seperate caliper in for the handbrake then henka???

No. The rear circuit will be routed through the handbrake. I think it's called fly-off handbrake. When I jam the handbrake I use the same circuit as the pedal to engage the rear brakes. I'm using a balance bar for the brakes so my front and rear circuits are totally separated.

Ok the discs would be heavier but a 300 x 22 is heavy too.

Also, I've been doing a bit of calculating and with the calipers I entend to use, 280mm would be better for brake balance - car has virtually no weight in the back as it's absolutly gutted with only a 30l fueltank and battery in the trunk and that big hunky engine out in the front...

[S2central.net]

Alright all this talk of rear brakes and discs has my mind going. Here is my stage 2 kit I am building for my coupe. It\'s a 300mm by 22mm (11.75\" by .81\") wilwood straight vaned rotor. I got the hat for pocket change so a $35 is perfect for this. The carriers are s8 units as most are using calipers are g43\'s from a 200 20vt or t44 avant or V8q. The S8 carrier will clear this disc and the hats are perfect for the set up becuase the hat height from surface closest to rotor to top of hat on a 200 20vt rotor is ~27mm and my hats are 26.5mm so that means my rear rotors are going to be 300mm by 22mm by 48.5mm IIRC.

This is to go on a CQ and have a matching front rotor of 328mm by 28mm (12.90\" by 1.10\") with 996 rear calipers. This is to replace the current stage 1 kit of 996 rear calipers on 12.2\" by .81\" (310mm by 22mm) front rotors and 200 20vt rear rotors.

Are your CERTAIN that the S8 carrier (for 280x22) fits over a 300mm disc on the rear of Coupe ?

Have you dry fitted this yet ?

I have all the parts ready to try this anytime soon - My 300mm discs are with a machinist today for a quote on being reduced to 280mm... I opted for that as I couldn't see how the S8 carrier would have enough reach for the 300mm disc... And I know that MarkH fitted up with S8 carriers on a modified A3 front disc at 280mm.

I have dry fitted the S8 carriers with the S6 calipers and the S8 pads - all perfect - the spring clips on the pads are just perfect and there is over 22mm width between the pads with the piston wound home fully. Also happy to say that S2 rear hydraulic hoses fit the S6 calipers... This is NOT true for the alloy variants used on the S8 by MarkH as he needed to get custom brake lines made up. Thats a result by luck.

Paul

Wish I'd dry fitted this combination at 300mm on the car now though.

[S2central.net]

Just remembered I still have the 8E0 carriers on the bench - I'll measure those for 'reach' in comparison to the S8 carriers tonight ! It would be a shame to reduce the disc/rotor size if I don't have to !

[v8 coupe]

Just remembered I still have the 8E0 carriers on the bench - I'll measure those for 'reach' in comparison to the S8 carriers tonight ! It would be a shame to reduce the disc/rotor size if I don't have to !

I don't have the S8 pads or 300mm discs yet (well actually 298mm or so 11.75" rotors) I am still working on getting my parts all together for that I am going to order the rotors soon they are 70USD for a set . I am almost positive they will work. The 200 20vt/v8 rotors aren't the largest you can fit under that carrier and the S8 isn't the biggest I'd guess either. I can always shave the 300mm rotors, but I am more likely to clearance the bracket if it's close. I was told, by someone that has a great deal of info on Audi brakes and sold several of these in the US.

[S2central.net]

Well I compared the S8 carrier (for 280x22) and the 8E0 carrier (for 300x22) tonight on the bench and I think the S8 carrier will indeed accomodate the 8E0 300mm disc

I am *NOT* getting the 8E0 discs shaved until I dry fit everything but it looks good. All I need is 5mm spacers for the S8 carrier but thats easy.

Photos to come...

[v8 coupe]

That\'s great I am almost certain they will fit. I still need to find a source for S8 pads IIRC they are the same as the A8, but not 100% curtain.

I am looking to run some EBC preformance pads in those and in the 996 rears that will be hugging some large front rotors till some 996t or other large piston calipers are needed up front then it\'s on to bigger badder things.

[S2central.net]

Nope - the S8 carriers will NOT accomodate the 300mm discs... Just had it all on the bench and compared with the 8E0 carriers... Whilst the two carriers have enough 'reach', the 8E0 carrier has much wider bolt spacing for its larger caliper.

I had both options on the bench and measured approx 20mm difference in the diagonal distance between the carrier/hub mounts (across) the centre - so looks like I'll be getting the discs reduced to 280mm after all.

I have photos to come. Its also worth noting the S8 carrier and pads on the 300mm disc leaves a lot of untouched area on the discs - so there will be no reduction in braking effort anyway.

Paul

[S2central.net]

Photos here - http://homepage.mac.com/nugentp/PhotoAlbum15.html

[markrs2]

Has anyone thought of trying the B5 RS4 rear brake setup?

Disc 312x22

Tried it on my UR with s2 rear suspension and it bolts up perfectly if you change the hubs for the RS4 ones. If I remember correctly this pushes the hub face out by 4/5mm's. Not sorted out the handbrake cables yet though.

[S2central.net]

Dunno what the disc offset is on that and I would also expect the handbrake to be wrong for Coupe.

I have now got my 300x22 8E0 discs spun down to 280mm diameter and a dry fit seems perfect with the S8 carriers, S6/RR calipers and S8 pads. Fitting later this week with new brake lines and I should sail thru the MOT (on brakes at least).

Cost me £20 to get both discs spun down locally - well happy ! I can see light at the end of the rear brake tunnel now


Cheers,

Paul

[90quattrocoupe]

Dunno what the disc offset is on that and I would also expect the handbrake to be wrong for Coupe.

I have now got my 300x22 8E0 discs spun down to 280mm diameter and a dry fit seems perfect with the S8 carriers, S6/RR calipers and S8 pads. Fitting later this week with new brake lines and I should sail thru the MOT (on brakes at least).

Cost me £20 to get both discs spun down locally - well happy ! I can see light at the end of the rear brake tunnel now


Cheers,

Paul

Paul,
Do you have picture of how the pad rests against the disc. I was looking at the S4 disc too. On the A3 disc, the pad misses about 10mm toward the center. Do the pads sit pretty centered in relation on the S4 disc?

I am using UrS6 pads. Are the A8 pads any different?

Thanks,
Greg