RE: Stock Brakes?

[eph94]

I moved this reply out of the original thread since it was more OT over there.


Originally posted by Sarge
Just curious if you're using the stock pads/rotors/fluid at those track days - how does the car generally hold up to repeated track sessions?

Handling consistent throughout the day? (no shock fluid issues?) Braking consistent? (fluid boiling/pads liquifying/rotors warpig?)


For the front brake pads, I am using Pagid Grey. One thing about the Pagid Greys, though, is that quite often you will sound like a schoolbus when you brake on the street. It's random, so I usually gas up my car whenever the brakes are having a quiet day. I'm thinking of swapping pads in and out for the track. You wouldn't believe how easy is it to do with our stock Brembo calipers; I was shocked.

RS 15 Grey - Very high torque compound. It combines a 20% higher friction value than the RS14 with a slightly increased pad wear. Needs finesse to avoid over braking the car. Good release characteristic and a quick bedding in procedure. Although the "RS15" has very good modulation it might have an excessive bite for some applications.

I have also upgraded the stock brake fluid to ATE Super Blue.

Changing the brake pads and brake fluid seems to have made a huge difference for me. Brake fade has been minimal since the change, one exception being when we ran half of the NASCAR oval at NHIS. With this 1.6 mile track setup, you come screaming out of the oval and then dive into a 30MPH hairpin righthander. After about 15 minutes into each session, I did notice some brake fade and my tires (Pirelli Pzero Rosso) began to overheat as well. Let me just add here that I have only six days of track experience so I am VERY hard on the brakes and braking is where I consistently get the lowest marks from my instructors, though I have made huge strides from day one to day six.

My first track day was a Lime Rock. I had stock everything and my brakes faded in every session, so I made the changes noted above. Fast forward to track days five and six at Lime Rock and I experienced no brake fade at all. However, I'm not sure if it is an apples-to-apples comparison since the Driver on Day One is very different from the Driver on Days Five and Six.

Watkins Glen next month will be the true test. I was told that there was someone in an RS6 last year who melted his stock brake pads in a day there. I'm not sure whether he was a novice or an experienced track person though. The more I spend time on the track the more I realize how much more important the driver is than the equipment.

Regarding the handling through the day... :0: !

[rs6_newyork]

my understanding was the problem was not so much pads and fluids - as you say that can be easily improved - but the rotors overheat to glowing point because the float although a good idea, isolates the heat, and they do not get enough air, so stress cracks quickly form, usually extending from the nearly useless cross drilling holes?

also if you use the e-brake at the end of a session you may damage the rear brakes, by extended contact with hot rotors?

final question: since you tracked the car a lot obviously, have you verified whether the oil pan is baffled or anything?? a momentary loss of oil under 0.8g wouldn't be a great thing..

[eph94]

Originally posted by rs6_newyork
my understanding was the problem was not so much pads and fluids - as you say that can be easily improved - but the rotors overheat to glowing point because the float although a good idea, isolates the heat, and they do not get enough air, so stress cracks quickly form, usually extending from the nearly useless cross drilling holes?

I saw that video of glowing rotors but I don't think I have even come close to replicating that. I do have some "stress cracks" but I don't think they're anything out of the ordinary for rotors that haven't been cryogenically tempered. Regarding the cross drilling holes, I'm not sure how much they help. I have brake pad dust that has been packed in them since my second track day. I used to clear the dust out of the holes but I was told by a brake distributor that I don't need to do that--it's the internal venting that the dissipates the majority of the heat (if I understood him correctly). I also noticed that the brakes do "ping" for a long time when they are cooling down and people ALWAYS ask me what that pinging noise is. At NHIS, I could even hear them pinging on the track during the straights, and then they pinged in the paddock for over an hour!


also if you use the e-brake at the end of a session you may damage the rear brakes, by extended contact with hot rotors?

That's a definite NO to the e-brake. Talk about a receipe for warping rotors! I was told that one person actually fused his pads to his rotors when he did this. One good thing about the RS6 being a slushbox is that we can just throw it into Park and it won't go anywhere. I've seen people put a strip of duct tape of the e-brake as a reminder not to use it.


final question: since you tracked the car a lot obviously, have you verified whether the oil pan is baffled or anything?? a momentary loss of oil under 0.8g wouldn't be a great thing..

This I have no idea! :mech:

[rs6_newyork]

Yeah i heard cross drilling is a hang over from the old days where pads would emit gasses under stress and the holes would let them out instead of riding a slippery cushion of gas. They also help a bit in the rain.

But all in all a better solution is slots, which help in wet, and if they are shaped right may even help a tiny bit in cooling. Although they still are places where stress cracks grow from.

Are your rear rotors in much better shape than the fronts? it is hard to believe one couldn't duct the inner part of the rotors (where the air is sucked in due to rotation anyway) via some under body air scoops that didn't extend too much...

PS: what was the rs6 lap time at lime rock? I went round there this week in a formula dodge at 1:03 :D

[7:53 RS6]

The reason my rotors was glowing and stockpads burned was the use of R-tiers. The grip comming from these tiers overall and of course under breaking is a killer for the breakes. Street tiers is of course the best way to go on a heavy thing like the beast. When driving my street tiers on track im no where near making my rotors look like Lemans style

By the way its nice to hear that you track her, its pure fun i think aswell.
Hoping to track Nurburgring again in august or september.

[Hy Octane]

I think he means Tires and Brakes..:)

[eph94]

Originally posted by rs6_newyork
Are your rear rotors in much better shape than the fronts? it is hard to believe one couldn't duct the inner part of the rotors (where the air is sucked in due to rotation anyway) via some under body air scoops that didn't extend too much...

Rear rotors look incredibly good and so do the stock rear brake pads. It makes me wonder how involved the rear brakes are in stopping the car.


PS: what was the rs6 lap time at lime rock? I went round there this week in a formula dodge at 1:03 :D

I've been going to car club "high-performance driving schools" where they explicitly don't allow any timing devices. I guess that would make it a "race" and then there would be insurance issues.

[SpinEcho]

Originally posted by JJV-MA
Rear rotors look incredibly good and so do the stock rear brake pads. It makes me wonder how involved the rear brakes are in stopping the car.

I don't think the rears do much work at all. This is a flaw on all VW/Audi group products. At least a month ago, there was a thread that talked about the compromised design of the rear calipers (incorporating the handbrake) and the superior design of the Mov'it conversion (fixed rear calipers with a separate parking brake).

As for the cross-drilling, I agree. It's mainly for show, perhaps giving better initial bite in wet conditions. Slotting is a superior solution, as it avoids stress crack formation around holes, and the dust accumulation in the holes.

[7:53 RS6]

I have changed stock front pads five or is it six times since march 2004, still havent changed once in the back but soon i guess change is needed. (many times i orderd real pads like harder pagids but did not show upp in time, better order from you guys in the usa next time)

[7:53 RS6]

Originally posted by Hy Octane
I think he means Tires and Brakes..:)

Thanks:)

[gregoryindiana]

From what I've heard and read, the Movits do a better job of dealing with the heat in the brake rotors partly by addressing the fact that in the RS6 stock setup the rears do almost none of the work. So putting more workload to the rear rotors is part of it, and so is increasing the size of the rotors. That way, during braking, your brakes have more metal mass to absorb the heat load.

Meanwhile, between heavy braking, it would be nice to direct more cooling air to the brakes, but I read in an earlier thread (by Nordschleife, who has apparently sacrificed much stock RS6 brake parts in the cause of heavy braking research), that this is very difficult.

Remember, the floating rotors are nice to the wheel bearings as they do not transmit as much heat to the hub. Higher temp brake fluid will keep it from boiling, to answer that end of the problem.

[7:53 RS6]

But that key is not free! We have been thru it before in previus threds. And Im not the onley one i think to say its not whort it. The complete kit is almost 7000-8000eur.

The stock setup is not that bad with the propper pads!

"Life is a compromise when limited funds"

[gjg]

Complete kit is I believe 8,100 Euro list price, replacement pads about 360 and rotor (per unit) about 410 Euro.

You need to compare cost on stock rotors and pads where you can reasonably expect replacement avery 10-15k km when driving in/around Germany? It seems that over 100,000 km you would probably spend same amount of money including the cost of tnew setup.

My brake pads started squeling horribly in less than 7000 km and the brake performance was going down - all that after few hard stops on autobahn .....

As my granfather always said - if you want to dance, you have to pay the music.

[7:53 RS6]

Originally posted by gjg
Complete kit is I believe 8,100 Euro list price, replacement pads about 360 and rotor (per unit) about 410 Euro.

You need to compare cost on stock rotors and pads where you can reasonably expect replacement avery 10-15k km when driving in/around Germany? It seems that over 100,000 km you would probably spend same amount of money including the cost of tnew setup.

My brake pads started squeling horribly in less than 7000 km and the brake performance was going down - all that after few hard stops on autobahn .....

As my granfather always said - if you want to dance, you have to pay the music.
As you can see im not a dancer.
Do you mean your stock brakes dident work after 7000km becuse you stoped hard some time?
Can you please explain what you mean with replacment avery 10-15km on pads and rotor, did not undersand that part
:)(sorry my english is not the best)

[eph94]

Does anyone know much do the stock front rotors cost to replace?

[7:53 RS6]

Originally posted by JJV-MA
Does anyone know much do the stock front rotors cost to replace?

In Sweden 2 front rotors cost ca: 1080eur list price. But can be bought for ca:880eur if conected on Audi.

[gjg]

Do you mean your stock brakes dident work after 7000km becuse you stoped hard some time?

rotors got overheated and bit hard after I had to do few quick (and couple of panic) 270 to 60~100. Brakes did work but in high speeds (240-280) the feel was different and not quite as grippy when new.


Can you please explain what you mean with replacment avery 10-15km on pads and rotor, did not undersand that part

I took the car to the dealer and they told me that the pads and rotors (front that is as far as rotor goes) are pretty much same time event in our driving enviroment. Their estimate was just what I wrote (10-15k km) - and they have 3 RS6 they are servicing. At that point they were going to do rotors under warranty, pads not, I do not remember the cost on pads.

So from the above is my calculation on Movit setup which should be - long turn - more cost effective, not to mention performance.

gg
:idea:

[7:53 RS6]

Originally posted by gjg
rotors got overheated and bit hard after I had to do few quick (and couple of panic) 270 to 60~100. Brakes did work but in high speeds (240-280) the feel was different and not quite as grippy when new.



I took the car to the dealer and they told me that the pads and rotors (front that is as far as rotor goes) are pretty much same time event in our driving enviroment. Their estimate was just what I wrote (10-15k km) - and they have 3 RS6 they are servicing. At that point they were going to do rotors under warranty, pads not, I do not remember the cost on pads.

So from the above is my calculation on Movit setup which should be - long turn - more cost effective, not to mention performance.

gg
:idea:
Pads and rotor same time event, well the guys at that shop sure knows how to make money.
Regarding the calulation on movit i can agree with better preformance but not more. I think with better pads the stock setup is ok.

[gjg]

I will also look in to Pagid pads when the time comes.

Problem with front rotors - pretty much baked .....

[Bauer]

Does anyone know much do the stock front rotors cost to replace?

Dealer COST (US) is
Pads about $375.00
Rotors $440.00 EACH

Retail is
Pads $528.00
Rotors $597.00 Each
This comes from friend who is parts guy at local dealer

Hope this helps

[eph94]

Originally posted by Bauer
Retail is
Pads $528.00
Rotors $597.00 Each
This comes from friend who is parts guy at local dealer

Hope this helps

Helps a lot, thanks! At "just" $1194 for a set of front rotors, I'm not sure if I can quite justify/rationalize upgrading to the Mov'it setup once my front rotors are cooked--4650 euros (~$5600 usd)for the 370x35/6S1 front brake upgrade. I do so very want those Mov'its though.

[7:53 RS6]

Originally posted by JJV-MA
Helps a lot, thanks! At "just" $1194 for a set of front rotors, I'm not sure if I can quite justify/rationalize upgrading to the Mov'it setup once my front rotors are cooked--4650 euros (~$5600 usd)for the 370x35/6S1 front brake upgrade. I do so very want those Mov'its though.

If upgrading to movit its a good idea to throw in the rear as well. The rear relly helps up the car as mentioned before by my good friend Nordo.:)

"Life is a compromise if limited funds"