a4 1.8t rear brakes

[aragorn]

hi there, i have a FWD 1.8TS A4 B5, and am looking at upgrading the rear brakes

The car is currently standard however im looking to fit 312mm disks to the front in the near future. The rear brakes are however pretty knackered and will need replacing soon. I think at least one caliper is possibly siezed and the disks are pitted badly so will all need replaced. I'm wondering if its possible to upgrade them while im there with S4 or A8 rear parts.

I've found a conversion guide detailing fitting the A8 carriers to the quattro A4 with S4 calipers but it doesnt mention the FWD cars and im not sure if these will fit a FWD car?

If the A8/S4 stuff wont fit then is there any other combination that will work?

Thanks in advance

Kevin

 

[aragorn]

bump.

18 views and no replies? someone must have an idea if the s4/a8 parts fit a FWD or if not something that will fit a FWD car!

kevin

 

[Siena]

I too have S8 Brembos to go on the front of my B5 quattro, the set-up should be the same for any B5 FWD model.

They are radial mount, so going to get suitable MOVI-IT style carriers.

 

[aragorn]

hi there, i think we've got crossed wires slightly, im referring mainly to the rear brakes...

for the front i'm just going to use the TT carriers and keep the original calipers with the A6/A8 disks

as for the rear ive done some looking and discovered the FWD B5 uses a disk and hub integrated into one, every other model uses a seperate hub and disk including B6> FWD cars, so while the calipers may well fit the car the disks wont, and as the hub is integrated its basically impossible to get a larger disk for the rear

looks like i'll just have to replace whats there with standard stuff.

Next question, anyone know if the later alloy calipers will be a streight swap for the early cast iron ones?

 

[macca]

possibly an expensive option, but try calling Hi-spec to see if they have a configuration for the rear. i'm going 330mm AP's on the front eventually and am leaving the rears as standard.

 

[mwarrey]

Why do you want to upgrade the rear brakes ?. I can see the point in upgrading the fronts if you have to, but on a fwd most of the braking force is on the front not the rear. Unless you are planning a massive power upgrade I would just use standard components on the rear (maybe upgraded pads). The last thing you want is to go too far in upgrading the rears.

 

[aragorn]

Why do you want to upgrade the rear brakes ?. I can see the point in upgrading the fronts if you have to, but on a fwd most of the braking force is on the front not the rear. Unless you are planning a massive power upgrade I would just use standard components on the rear (maybe upgraded pads). The last thing you want is to go too far in upgrading the rears.

as i said in my original post, if i'm replacing everything anyway and there was a cheap upgrade available then i'd do it

the braking force distribution on a RWD car is no different to a FWD car, they're both massively biased to the front, however if you upgrade the fronts you shift the bias more to the front than before, this means your more likely to lock the front brakes (ie trigger the abs) than if the car was balanced

i plan to upgrade the fronts and was simply looking to see if it was possible to upgrade the rears similarly.

remember audi upgraded the rears on the S4, and they wouldnt spend the money doing that for no reason.

 

[Oranoco]

Actually there is usually quite a difference in braking bias between FWD and RWD cars. On FWD it can be as little as 10% of the braking whereas RWD is typically more like 20-25%

 

[mwarrey]

remember audi upgraded the rears on the S4, and they wouldnt spend the money doing that for no reason.

The reason Audi upgraded the brakes on the S4 is because it has close to twice the power of a 1.8t, its 4wd and is heavier.

It can make sense to see if you can upgrade when replacing worn out parts, all I am saying is don't get caught up in upgrading just for the sake of it, especially when it is unlikely to make much difference. You may be better spending elsewhere.

I have fallen into this trap myself in the past. Spent a small fortune upgrading the rear drums on a mk1 GTi to disks. Looked a lot better and impressed other owners but did little in terms of extra braking over the original drums. Also saw a post recently of someone who upgraded their rear brakes to rs4 spec before doing anything to the fronts.............