Brake performance in wet weather...

[RacingTeatray]

Do A3s/S3s suffer from the brakes getting wet or covered in muck/salt during high speed winter driving in wet weather???

Very occasionally on long wet motorway journeys where I haven't needed to brake for say 30mins or so, when I go to brake there is practically no response initially. Which can be scary. I have to really stomp on the brakes to stop and then thereafter they work fine again. It seems to be a winter phenomenon - I last noticed it stopping for a peage in France last February and then it happened again this year on the autobahn in Germany two weeks ago. It was wet (surface spray) and salty (was snowy) and I had to brake hard at approx 110mph and absolutely nothing happened at first. The brakes did eventually bite but I absolutely bricked myself.

The brakes themselves are fine - the car had a brake fluid service last month - so not sure what's causing it? Never had this problem with any previous car.

 

[imported_Stewart]

Yeah i get this after washing the car, takes about 5 secs of braking to warm them up enough to get rid of the water....

 

[bampy]

Whenever you get the brakes wet on a car, you should always brake to get rid of the water. It tells you this in the highway code.

Rather than stomp on the brake pedal, just apply gentle pressure to the brake pedal for 10-15 seconds and it will dry the brake discs.

 

[Timbo]

I've been getting this of late as well... glad to hear it isn't just me! I must say I've never had this in any other car. Are the discs made of something other than mild steel? Old Honda bikes used to suffer from this a lot because they had (I think) stainless discs.

 

[Paul-RS6]

Brake performance in wet weather.....


to finish this sentence for the S3....


is crap....


one of the main reasons i opted for the Porsche brake set up.

 

[simch]

Revivied this thread!
Thsi happened to me on the autobahn inn Germany too last week. weird feeling, just thought it was cos it was very very wet, but never happends in my Mk4 with the same brakes on it......??

So I had a look around and apparently Audi are aware of this and have brought some upgraded parts out to stop or at least reduce it! I think its known as an NBL upgrade (IIRC) and is some front disc backing plates, and weird lookng plastic deflectors that attach to the bottom arms wiht tie wraps I think!!
Anyone fitted these or had them fitted? Apparently soem Porkers have similar and there is also an increased cooling effect too in the dry, presumably it sincreases ariflow over the disc surface and keeps the water off them......?
But still cant understand why the mk4 does not suffer.....? Must be different airflow under the car?

 

[OutLore]

I've just seen a commercial on TV here in Dallas for the new 3 Series BMW, which apparently applies the slightest of pressure to the pads when it's raining (it uses the auto wiper sensor) to alleviate this problem.

The commercial didn't say whether it's a permanent pressure or a few seconds of pressure every 30 seconds or so... I would imagine that it would have a detrimental effect on pad life, even if it's just a feather touch though....

I thought it's a nice idea all in all though

 

[jojo]

My Brembo's work a treat

 

[Ess_Three]

I removed the disc shields from the inside of the discs as I found they seemed to stope water getting out once the brakes were soaked, and they stopped the brakes getting enough cooling air when using them hard.

Win, win...

 

[simch]

I removed the disc shields from the inside of the discs as I found they seemed to stope water getting out once the brakes were soaked, and they stopped the brakes getting enough cooling air when using them hard.

Win, win...

Yeah, I think the new backplates are further away and these weird deflectors alledgedly increasing airflow over the disc too, to help cooling and dispesrse water..?l Its all audi parts, just wondered if anyone had got it fitted or not? My S3 is maybe one of the later ones on a 53 plate and it does not have this kit on as far as I can see.

Interesting as the site I saw it on "S3 passion" also reports veering to the right in rain as the RH front disc is warmer and dryer due to the first intercooler being inder that side wheel arch......!! I can see its possible, but does that really happen in practice???

 

[Ess_Three]

Interesting as the site I saw it on "S3 passion" also reports veering to the right in rain as the RH front disc is warmer and dryer due to the first intercooler being inder that side wheel arch......!! I can see its possible, but does that really happen in practice???

I can't see it...
On standard boost the charge temperature isn't enough to effect it...and for the difference to be felt you'd have to be doing not much more than walking pace...hardly likely to affect the brake cooling at that pace!

I certainly never experienced anything like it...

 

[simch]

Sounded all very theoretical!! But those Frenchie's say its so!! A nice theory if it is true though!!
Weird that all mk4s seem to pull to the left on braking...maybe the intercooler on them overheats the rh disc! !lol!

Still interested in this kit though, it seems it may actually be amde up form audit parts bin with S2 back plates and defelctors off something else!

 

[ChriS3]

Porsche brakes work fine in the wet, so did the standard brakes. If you're using them they dry out pretty quick. The limitation of braking in the wet has always been tyre grip for me.

 

[ChriS3]

Interesting as the site I saw it on "S3 passion" also reports veering to the right in rain as the RH front disc is warmer and dryer due to the first intercooler being inder that side wheel arch......!! I can see its possible, but does that really happen in practice???

The S3 has intercoolers in front of both wheel arches....

 

[simch]

...........yes, but apparently the first one in the systme, has hotter air flowing off it, backwards and "drying" off the RHS disc and causing the brakes to pull to the right in wet on initial application.
The stock brakes certainly do have the tendancy to be very very poor after miles on autobahn in v heavy rain, I had it myself in Germany last week. The new backplates and defelctors are designed by the guy who designed a system for Porsche (alledgedly) and it does reportedly work!

 

[ChriS3]

Lol, heavy rain? Try spending a summer driving in Scotland....

The porsche ones have a vent pipe/air feed to keep the heat down and dry off the discs.

 

[simch]

I dont doubt the porsche brakes are excellent! I have them on mine!! (Porker that is!)
But this seems to be an acknowledged problem from Audi, not what you expect on a semi performance car like the S3 IMO! Weird thing is, as I say, I run the self same brakes on my Mk4 and they are excellent, with no tendancy to do this at all. It can realsitically only be due to local facotrs when fitted to an S3, (brakes they are designed for though!), and presumably it is an airflow issue!!
So back to my original question having revived this thread! !! Has anyone had this update fitted, the different backplates and deflectors and if so was it fitted by dealer, self fit etc? Were any of the later cars fitted with them?
And anyone who has it, does it indeed make a difference, as our "S trois" owning coleagues accross the water say it does......?
Strange thing is, that they report its particularly noticeable when the roads have been salted and its raining heavy, exactly the conditions I was in last week. Reports suggest its having been cruising at higher speeds for a long time without using them, in my case I had not touched them for probably half an hour or so, but whether its only after this amount of time it occurs, I dont know? Maybe it can ahppend after a few minutes? Maybe its their road salt.......!?!?! !!! As I say I have not yet experienced it in the Uk, but I have experienced brakes that are far less capable on the S3 than the same equipment on my Mk4! Weird!!