RS5 Carbotech and ECS feedback, dust boot failure advice, please

A5/S5/RS5
#1

First post since getting my RS5 cabriolet 1 year ago; nice to be a member. Some advice, please.

I took the RS5 cabriolet to Road America in mid October, thought I would post my experience.

I took it bone stock to Autobahn Country Club track in Joliet, IL in July, a track I have run for 50 or 60 track days, hundreds of laps. It was wet for the first session, and I enjoyed blowing off vettes and vipers that had to cool it in the slippery stuff. I kept the nannies on for the early laps then dialed back to the competition mode, but did not turn them off. Then the sun came out. 40 min total and the front pads were done. I headed home.

After reading up on others’ experinces I ordered a set of Carbotech XP 12s in the front, and a set of ECS rotors, which only come slotted and drilled but seemed to be a reasonable, less costly alternative to the stock rotors. I had a set of XP8s installed in the rears, with the idea that I could leave the XP8s on in the rear and do the quick-change for the fronts with 1521 street pads and have a setup with an easy change for track duty. The fluid was Endless DOT4, which is the new factory fill for GT3s. The pads came pre-bed from Carbotech.

I took the car to Road America with that setup for the last track weekend of my season. It was cold in the AM (36 degrees and windows down required…), and overall the car did well for the first few sessions, 30 minutes each. The handling was confidence-inspiring, but the car felt as nimble as one might expect from a 4,400 pounder. As the day wore on, there was some extra pedal travel at the end of the sessions, and I was sure to do some extra cooling off on the street between sessions.

After 1.5 hours on track, the front pads were noticeably worn but I had enough for one more session. Spider webs cracks had already begun to form on the rotors. At the end of that session, the setup was done:

Outboard pads were at the backing plate, and the dust boots had deformed:

http://i14.photobucket.com/albums/a348/vette_ruminator/IMG_2700.jpg


http://i14.photobucket.com/albums/a348/vette_ruminator/IMG_2710.png


http://i14.photobucket.com/albums/a348/vette_ruminator/IMG_2711.png

and the rotors looked like they had way more than just 2 hours/4 30 min sessions on them:

http://i14.photobucket.com/albums/a348/vette_ruminator/IMG_2736.jpg

The tires were the stock PZeros, and I tried to keep the pressures in the upper 40s hot/40 cold. The rear pads had plenty left.

I’m sure there were factors related to extra wear: I started the sessions with the nannies on until I knew what the track surface was like. The very cold temps meant large temp swings on the rotors and cracks may have been accelerated from this, etc.

That being said, one of the instructors happened to bring his wife’s RS5 cabriolet and they had spoken with Carbotech before the event. Based on the abuse the car would take, Carbotech suggested XP24s in the front, XP12s in the rear for the 2 day event. At the end of day one, when my setup was done, they had nowhere near the same wear, he felt that setup was good for maybe 3 days. He was on the stock rotors.

For comparison, a buddy of mine brought his unicorn to Road America: a blue Cadillac CTS-V wagon with 550 hp and 4,600 lbs. His stock rotors are blanks, and he used Hawk DTC 70 front, DTC 60 rear. After 2 days, he still had plenty of pad left. Food for thought.

At this point, I need to take the XP8s off the rears because the noise when they warm up is driving me nutty.

I need to have the dust boots replaced, and I wonder if anyone on the forum has had this issue. I have been to a few highly regarded local shops and they say they will get back to me re whether they can get the boots or a rebuild kit, but they don’t seem to have any answers. I may have to suck it up and go to the dealer and pray for a warranty repair with the thought that the part should not have failed, but I’m not hopeful. The 1521s are on at this point and the pistons are therefore pushed back and not exposed. There are no leaks and the pedal pressure etc is normal.

Any advice re the dust boot issue??

Thanks

#2

Welcome to AR! ;D

Much better place to post in terms of something technical…

#3

Here’s some RS5 brake related threads to get you started… :slight_smile:

http://audirevolution.net/forum/index.php?topic=2372.0

http://audirevolution.net/forum/index.php?topic=2379
(I wish the how to thread could get a sticky)

#4

^^ Which thread do you want stickied?

Edit: nevermind. I see which one you were referring to. It’s been stickied.

#5

Thanks. I have read your brake pad changing post in the past, it’s really useful.

Do you know where I can get replacement dust boots? It sounds like you have had to replace yours…

#6

Thanks man!

#7

Thanks, man!

In regards to the dust boots, I’m not sure. I have not yet replaced mine. There are cracks here and there, but they’re not nearly as bad as yours (which in essence, is pretty much done for).

You could always ask the stealership, but I typically ask my local shop (Achtuning) to source stuff for me.

I found this:
http://centriccatalog.com/Inquiry/AppResult.aspx?id=WEB_CALPIS&v=LD&y=2013&m=73&mm=22581

Which will be handy when I want to get the calipers rebuilt.

#8

Welcome great first post.

ECS rotors tend to not hold up very well. Anything cross drilled will crack but cracking that fast is showing they are not quality. The dust covers look like that because you didn’t get the heat out enough. Part of that is part of the rotor not deflecting enough heat. I know some guys use different break fluid to pull out more heat trying to keep things happier. I know you can rebuild them I just don’t know where would be the best place to go. Your in good hands with PsYkHotik

#9

Amazing brakes destruction. A little bit of mass (is it really 4400 lbs???) and some spirited, experienced driving with confidence inspiring AWD = near destruction of the stock brembo setup in a couple of hours. Incredible. Are these 2 pad per side, eight piston fronts like the RS4?

The second setup, the combo of those ECS rotors + those pads might be the issue leading to the premature pad wear. Those aggressive pads might not play nice with ECS. The ECS rotors…I don’t think many people use them for tracking their cars. They’re more of a stock replacement. You might want to ask the RS4 guys about combinations that work, since the cars are very similar and the rotor selection is as well. I’ve heard the track focused Rs4 guys complain about the ECS stuff before.

I’m a bit surprised the stock setup didn’t last better. You said the car was 1 year old when you took the car there on stock setup…and you killed the pads after a few sessions. How many street miles were on the pads before you got there?

#10

Welcome. Do you have any pictures of your RS5 cab?

I am always amazed at how people can wear out a set of brake pads at a road course event. Those pads are shot.

By the way, ECStuning shows the same caliper rebuild kit for the RS5s as the RS4s with just pistons and seals but no dust boots. So I don’t know if you can get new dust boots separately.

http://www.ecstuning.com/Audi-B8_RS5--4.2L/Braking/Caliper/ES349297/

#11

Yes, they are 2 pads per side, 4 pads per caliper, 8 piston. The ECS failure was a combo of drilled (never again if I can help it) and likely sub-par material, especially compared with Brembo 2 piece aftermarket kits, but I didn’t want to spend $2500 on a set of rotors. The car probably had a about 7500 miles on it.

#12

Thanks. Their kit for a total rebuild was in a couple hundred $; I was thinking less than $50 for the rubber parts. The hunt continues.

Insert gratuitous fall track photos here:


http://i14.photobucket.com/albums/a348/vette_ruminator/M4S_3172.jpg


http://i14.photobucket.com/albums/a348/vette_ruminator/M81_3310.jpg


http://i14.photobucket.com/albums/a348/vette_ruminator/LM4_0200.jpg

#13

yep, it really is 4,400 lbs plus me! Not a svelte track car… physics will always win that battle.

#14

Great pics!

The XP24 lasts me 4 track days. I’ve resigned myself to that fact. But you will need to alternate rotate your track pads criss crossed per caliper after one day, and swapped to the other side for the next day. (I criss cross on the same caliper, then the next day, I remount in the same top/bottom orientation on the other wheel except for the pads that were mounted on the ‘inside’ are now mounted on the outside side of the caliper on the other wheel - and then it gets criss crossed on the same sides for the next track day).

I noticed uneven wear for the pads (the top ones were wearing out faster). The reason for this? I’m guessing it’s that the calipers have 8 pistons that are the same size… If you look at aftermarket BBKs, the piston sizes are tuned per vehicle (and different sizes).

Also, the front brakes will simulate a ‘torque vectoring’ effect at the limit. I’ve had to adjust my driving to avoid it coming on (off camber turns when you want to start dialing in the power seems to engage this). This will introduce unnecessary heat due to the application of the brakes. It will engage without the nanny lights flashing. You will feel it since the XP24 pad is super aggressive.

It also sounds awesome when driving around (I’ve gotten good at pulsating the brakes to make annoying sounds haha):
https://www.youtube.com/watch?v=GQS8WO-dxSU

One thing that might save the dust shields a bit is the titanium brake pad shields (well, it’s some sort of alloy). Though chatting with Mike Jr @ Carbotech, he didn’t recommend it as you’re reflecting the heat back into the brake pads (which in turn could overheat it). We’ll just have to keep replacing the dust boots (I’m not overly worried - my RS5 doesn’t see snow driving and the salt that’s associated with it - mainly because I never bought all season tires).

I have a bit of a debate with myself of whether or not to keep the stock dust shields on or off during track days. On one hand, it does have cutouts that has (very) subtle “scoops” to scoop in the air. But on the other hand, the rest of the dust shield will just reflect heat back to the rotors. I’m leaning towards ‘off’. A simple test for this is to compare the inner part of the rotor (the side facing your engine bay) with the outer side of the rotor. Which side shows more abuse (I’m guessing the inner)?

Taking the caliper off is pretty easy. Just need a flex bar with a hex bit, a torque wrench, and a small bungee cord to hang the caliper. I can update the brake thread guide with instructions (I’ll see if I have time this weekend).

And I’m happy to see another RS5 owner track their capable machine!

http://instagram.com/p/vKJN4HzCDk/

#15

Hey I was totaling up everything for my R8 calipers and RS4 front brakes when I found that ECStuning just added the dust boots for the RS calipers to their website. They are almost $35 for the set on one side.

http://www.ecstuning.com/Audi-B8_RS5--4.2L/Braking/Caliper/ES349298/

#16

It also says it is a genuine VW/Audi part… If it is, the search is over. Thanks!

#17

A couple things:

  1. Per Psykhotik, remove the front dust shields. This helps immensely with heat.
    Though be aware (and you probably already are) that it is no longer protecting your ball joints from heat. Replace joints more frequently, or rotors/pads. IMO, joints are cheaper :slight_smile: Just check for play after every track day.

  2. Do you have any videos of you driving? I hear you on the 40 to 60 lapping days… It’d be interesting to see how you are driving the car for things like…seeing when the torque vectoring is being engaged (per Psykhotik), but also how much you drag the brakes…

I have never gone through pads so quickly. 2 to 3 days and driving like an animal on pads that are not suited to the task (ie xp12 on a 400+hp car over 3500lbs) is a possibility. But 1 day…is crazy :slight_smile: And yes, XP24 or even RP2 is the way to go for the RS5.

#18

The RP2s will work but won’t last any longer than the XP24 (actually I got three days out of them - so slightly less). I’d rather just enjoy the crazy grab of the XP24s and completely late brake (with short braking duration - lol and wear the tires out even faster) then prolonged braking with the RP2 (that doesn’t grab as much).

There’s two schools of thought on braking (and the amount of heat it introduces to the braking system). One is the apply light pressure over a longer duration. The other is a higher pressure with the shortest duration (compressed braking zone).

I prefer the latter - and transition to trail braking if wanted/needed. If you want to save the equipment more, brake earlier (meaning you’re done before the turn in). I’m not very good at that (saving equipment). Though if anything, I make it my mission to avoid the front brakes from coming on during the exits in corners and adjust my driving to how the car “likes it” - if that makes sense - also seems to actually be smoother/faster since the car isn’t complaining). I do keep the nannies on (they’re not intrusive - for the most part - though I do get the lights blinking on some exits - especially in the rain).

And good point, boro92. Videos will definitely help as well. Don’t think of it as critiquing. Instead, more of pointing out what to look for and what to avoid/try. :slight_smile: Different cars and different driver/driving styles typically means there’s multiple ways to approach a corner. Pick and choose what works best. :slight_smile:

#19

Here are some Harry’s video links. The label says ZR1 but that car was at home… I couldn’t get the embed thingee working correctly

https://www.youtube.com/watch?v=6CSo7jdg_go&feature=youtu.be

https://www.youtube.com/watch?v=UefgdBZwpDY

#20

Nice vids!
I love it when the harry video overlay is put on there.
Very smooth driving indeed–however, it is actually what I suspected–you are dragging your brakes a little too much.
You can stand to brake later/deeper. It’s counter-intuitive, but if you brake deep and go into the pedal hard, you actually introduce less heat into the system. Imagine it this way:

Say on average, you are on the brake pedal for 2 seconds per corner. Then, you adopt a later brake technique and brake later but also harder into the corners. Your average time on the brakes now becomes 1.5 seconds per corner. That 0.5 seconds adds up to a lot of time not touching the brakes on the track–it gives the system a lot more opportunity to cool down and bleed off the heat generated.

In dry, sunny conditions, you can afford to do this. Obviously, it is not the fastest way if it’s wet–you absolutely cannot use the brakes this way in the wet. But in ideal conditions like your video, you can certainly do it. Not only will you find improved lap times, but you’ll find pad wear and fade is reduced significantly.

Another counter-intuitive point: I’m actually suggesting you to be aggressive with the brakes. That is, when you get on them, you roll into them hard. This is not to say you are stabbing the brakes like an on-off switch, but it’s almost there! You get on the pedal swiftly, and you quickly get into that pedal. You should be close to (and even sometimes) actuating the ABS in all corners. This is the difference between HPDE braking and race school braking. If you go to an instructor teaching you race craft and qualifying you for your license, you’ll find that the brake style race schools teach is very different from HPDE.

HPDE teaches smooth, progressive braking. This is actually a beginners technique to keep the car balanced…so as a beginner, you have less to deal with. However, someone with your ability, seat time, and smoothness can definitely adopt the “race” braking style. Try it out. I bet you’ll find 1 second a lap easy.