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pegbox7

B5 RS4 Brakes - What are the actual issues ???

As the title suggests what are the actual technical issues why they don't stop the car well enough at high speed... ( For increased performance cars )

Is it that the discs aren't big enough ?
Is it a pad size issue ?
Is it a pad material issue ?
Is it a Caliper Issue ?

Is it all of the above ?

OR

Is it possible that the OEM disc & Pad technology is 10 years old, and that actually if an up to date set of high quality discs were used along with new Pads and brake fluid that this would do the job.

Looking at the Calipers they look well engineered and plenty big enough to do the Job.

I know this discussion has been asked in many various forms before but i've not managed to find technical answers, just lots of posts from people who have swapped to different kits.

The reason for my post is to try and find out if actually there is a much easier and cost effective solution to upgrading the braking on a B5 RS4.

Any views are welcome...  
MilkybarKid

They stop well from speed a few times aye, so in that respect they are fine its just when people either start tracking them or want to buy bigger brakes to looks better they buy bigger ones
2 piston calipers on a 1.7ish ton car dont work very well.

Other than that, the cost of disks is ridiculous.
bluebrakes

rear b5 rs4 calipers are prone to seizing.
Give a horrible vibration rumble when they do.
Nez

I just upgrade to Audi RS4 B5 brakes and I am very happy with brake power.
GDS968

Pegbox - Have sent you a PM reagarding other disc manufacturers as I went up this route initially!
kiwi_rs4

If going with the B5 RS4s, DBA (Disc Brakes Australia) provide an aftermarket slotted rotor at around half the price of the OEM disc (at least in this part of the world). Could be worth a look. I've ordered some to replace my front discs but not tried them yet.

http://www.dba.com.au/vehicles/audi/rs4/2.7i-v6-biturbo
kiwi_rs4

A bit more info about the DBA 4000 series discs (available for the B5 RS4) in the video below:


Link
GDS968

Kiwi_RS4 Yes I looked at those also along with others but they just don't seem to be available over here. The importer has said he can't get hold of them!!
Searider

Is the B5 setup really that bad?

OR - are people really saying that "my shagged out worn discs and pads aren't very good and if i'm going to have to spend 600 on some new ones I would rather spend twice as much and think that i've improved by car".

My fronts are a little thin at the moment but still stop the car OK.  I imagine that with new pads and discs they'll be immeasureably better though.

I don't deny that bigger discs / better calipers are probably more effective but the standard set up can't be THAT bad can it?

I don't go on the track, so my comments are based on road use.
REDDMANN

they will be fine as long you dont track them...
Ghost

Searider wrote:
Is the B5 setup really that bad?

OR - are people really saying that "my shagged out worn discs and pads aren't very good and if i'm going to have to spend 600 on some new ones I would rather spend twice as much and think that i've improved by car".

My fronts are a little thin at the moment but still stop the car OK. I imagine that with new pads and discs they'll be immeasureably better though.

I don't deny that bigger discs / better calipers are probably more effective but the standard set up can't be THAT bad can it?

I don't go on the track, so my comments are based on road use.




Been said many a time.

And driving style probably has a lot do with it, I think some peeps use their brakes a lot more than others when driving fast.
sfrs4

searider i said the same as you about seven months ago and know i realise i was wrong! the brakes are poor! but how to address the problem is something i have been going over and over in my mind it comes down to either of the two options 1 as pegbox said upgrade discs pads fluid and lines or 2 get a big brake conversion. i just hope someone does both before i have to!!!!
MarkB

I found the B5 RS4 brakes on my 300hp S4 were fine... when the power went up a bit and the brakes a little older it was then becoming too much for them.

The pads I have fitted are the cheap Mintex off eBay though so that could also be the issue...

I wouldn't fancy tracking an RS4 with them!
scoobydood

I seem to recall seeing a couple of articles/reviews on the B5 RS4 where they praised the brakes?
kiwi_rs4

There is a list of UK suppliers of DBA products here: http://www.dba.com.au/dealers/united-kingdom/ I can't verify if it is up to date or not.

I have tracked my RS4 on the OEM discs and pads and I haven't had to change them yet even after about 6 track days, but they are getting close now. You only get around 15 - 20 minutes of track time on them before the brakes start to feel sketchy and that's when I do a cool down lap and come in.

I have a race car brake supplier here in NZ who says upgrading the pads and fluid will make a massive difference (a good source of info is here: http://www.racebrakes.co.nz/pdf/brake_upgrade.pdf). He has made me some custom pads for my fronts and as I said I have the DBA discs on the way.
sfrs4

kiwi if you get you hands on a set of dba discs would it be possible for you to give us your supplyers contact details so we could sort something this side of the world? it seem's it's a little to much like hard work for uk agents!!!
quattrokid

I verymuch doubt Audi wouldletloose a car of the B5's potential and not give it brakes to cope!!  how much time would have been spent on the N' Ring getting hammered to within an inch of its life if it wasnt up to scratch?

ok with persistant track days brakes will be cooked but I havent had any problems on road use brakes on our car and dont feel as if it needs bigger brakes... yes B7 ones do loook the bizz but is it justified to spend a grand on calipers alone to replace what already works?


B5 discs are a f'ing rip off and we dont have a choice other than OEM parts and for a 10 year old car still paying 1500 quid for a set of front and rears is nothing short of Dick Turpin high street robbery.
wjn

As far as I know the main problem is cooling of the brakes. So it depends on the riding style / track if the brakes are good or not.

Lot of "big-brake" kits have thicker disks (34 instead of 32mm), so can dissipate more energy before they get to hot. Also the B7 disks are 34mm, instead of the B5's 32mm.
sfrs4

as i said above i believed people were mistaken about the brakes and it was only those who abuse them, but i only drive my car as it was designed to be used (fast road) never been near a track!!! i still find that they are ok....... but nowhere near as good as other performance cars that i have owned (skyline, subaru [non brembo brakes], evo) even my wife's renault clio 1.5dci stops quicker at speed. and before you mention the weight issue audi should have thought of that when putting brakes on this car shouldn't they?
Searider

sfrs4 wrote:
as i said above i believed people were mistaken about the brakes and it was only those who abuse them, but i only drive my car as it was designed to be used (fast road) never been near a track!!! i still find that they are ok....... but nowhere near as good as other performance cars that i have owned (skyline, subaru [non brembo brakes], evo) even my wife's renault clio 1.5dci stops quicker at speed. and before you mention the weight issue audi should have thought of that when putting brakes on this car shouldn't they?


What condition are your brakes in?  New? 7 months old? old? very old?  Don't know?

It would be good to have input from someone who has replaced some worn standard brakes with some new standard brakes.

Kiwi seems to get on ok with standard kit on a 15 minute track session.
scoobydood

sfrs4 - on one hand you defend them and then on the other make the brakes sound horrendous! The 1.5dci stops quicker at speed. WTF?!?

In a single sentence you have confirmed all negative comments on the brakes.

I think perhaps you are confusing brake feel or initial bite with stopping power in your comparison. Having owned a 1.5dci and more recently a Nissan, both of who's brakes feel better than my RS4 setup - I can say with certainty that when it comes down to it they are nowhere near as good as the RS4 brakes. Like chalk and cheese when real stopping power is required.
pegbox7

I am glad i started this thread now as there are some interesting views and factual information.

The performance brake supplier that i have been in contact with is also shocked at the horrific cost of OEM B5 RS4 disc replacement as he feels that this is where the technology has moved on the most. He is adimant that a replacement set of modern discs and pads will transform the factory set up at a fraction of the cost.

I have fairly new discs and pads on the front of my car and they are genuine audi items. The brakes are OK but they lack bite and are very poor for higher speed stopping, ie when exiting a motorway onto a short slip road heading down to a roundabout where you need to bring the car to a stand still.

I know for track use they would be useless, but then to be fair most road cars wouldn't last long on a track ( except Exiges - totally biased  of course )
rick o'shea

Can't understand why Audi decided to go with only 2 piston calipers in 2001. Ford went for 4-pots for the Sierra Cosworth in 1986. And that only had 204bhp compared to 380 of the RS4. Suspect cost was a factor. Mind you the E46 M3 & CSL only has a single piston sliding caliper...
wjn

The RS2 had also 4-pots (Porsche/Brembo) on serious 304mm disks.

The 2-pot of the RS4 was also found on the S4/S6/S8 series of those days, so costs would be an issue, yes.
scoobydood

http://www.youtube.com/watch?v=beB5ZYUkznU

I know you have all seen this before - but watch 1m 25s onwards. Seems to stop pretty sharpish! The comparison to an S4 shows very clearly how much better the RS4 setup is.
Ghost

Mines a facelift S4 Avant and owned the car for approx 8 odd years.

After a few years it became time for me to completely rebuild the brakes as they were becoming tired. I thought about an upgrade however at that time cost was an issue so chose to rebuild with standard discs, pads (OEM German) and fluid, they were then bedded in correctly to optimise performance.

A few months after that business improved and it was time for the remap so following rather a lot of research found out about this Jonny foreigner who was supposed to quite good with s/rs2's and this lead to a custom remap.

During the remap process on a 'private road' at one point we needed to stop rather urgently from quite a high rate of knots and the brakes worked superbly with Minhea so impressed he couldn't believe I was running the standard set up.

I am probably only running 320bhp or their about however I am retarding a very similar vehicle mass to the rest of you peeps and so the power of the car in most cases is irrelevant.

Keeping the standard set up for road work only holds true for an S4 as the cost of replacements is fairly sensible however if I had an RS4 then I would not be buying OEM discs, I would probably be running high quality alternatives (DBA maybe?) or get custom bells/discs made.

And an RS4 with a 'brand new' brake set up all round, high quality discs (DBA), Motul DOT 5.1 brake fluid and decent pads say Ferodo DS 2500 pads (available?) would be a significant step above mine and I would of thought would be great for road work.

Not much help to you guys who want to track all the time as that would for me be a fairly involved project as I would not be throwing dinner plates and heavy callipers on the front of the car at a cost of approx 2K to end up with a spongy pedal.    

Just my 2p.
kiwi_rs4

My supplier for the DBA discs is http://racebrakes.co.nz/. I'm expecting delivery mid to late April.
You could also try contacting DBA directly, although I suspect they will just put you onto their UK distributers.
scoobydood

I emailed DBA and they did not even bother to reply. Makes my blood boil when businesses don't have the courtesy to reply to emails/voicemails etc.

Rant over
GDS968

Me too - thats why I gave up. If they can't be bothered then nether can I!!
1982deaks

I don't think there is a problem with the actual stopping power of the brakes, just the feel of them, they don't feel like they're going to work, you get the arse clenching moment, and then they do!  I think more modern cars just have better feeling brakes, even my transit vans feel better, and they take miles to stop!  just my 2p's worth
DavidT

I've moved the K-sport posts out to a new thread http://audisrs.com/about11822.html because they are off topic here.
kiwi_rs4

scoobydood wrote:
I emailed DBA and they did not even bother to reply. Makes my blood boil when businesses don't have the courtesy to reply to emails/voicemails etc.

Rant over

When I sent an inquiry directly to DBA they forwarded it straight to their NZ distributors without replying directly to me. I then received quotes from their 2 NZ distributors. You may find that this is what has happened and it is actually the UK distributors that haven't sent you a quote. I don't think DBA sell directly to the public. Just informed speculation on my part. Has anyone tried contacting one or more of the UK distributors? I would suggest the telephone as that way they can't ignore you!
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