cayenne brake upgrade ???? what rotors????

[pzp107]

I know this has been done so I wanted to see if someone can help me out with this. I just finally picked up a set of cayenne calipers for the front on my s4. I need to know what rotors and lines I need. I am pretty sure I read b7 rs4 front rotors or c63 rotors but cant find the info again. I also think this is the same caliper as the 6 piston rs4 brakes as well is it not? What style lines would be good to know to but I think b7 rs4 lines would work. Any help would be greatly appreciate as I am lost and dont want to do trial and error and searched my brains out.

[///M3 TO S4]

Rs4 brakes are EIGHT piston, FYI...not even close to the same caliper.

[pzp107]

rs4 brakes are 6 piston, rs6 brakes are 8 pistons. That much I know. I just know you can use the cayenne calipers which bolt directly up to the stock b5 s4 spindles. They require use of different discs like ECS uses which I dont want to use. I remember reading somewhere mercedes c63 discs are usable. Someone has got to knwo and their help would be appreciated.

[AddICTioN]

B7 RS4 brakes are 8 piston...they are the same as RS6. The rotor size Is a little different. As far as I know neither rotor will bolt up to the cayenne caliper.

[audimeister]

I have been doing a lot of research on this subject, and will share what I know so far. I don't have time at work right now to upload photos, but will later.

1. RS4 calipers are eight pistons, same as RS6. They are expensive, and judging by their complete failure when Champion used RS6's in the speed series (against Alcon, and Stoptech equipped cars) they may not be the hot ticket.

2. Cayenne calipers are available to fit 330 and 350mm rotors. I will concentrate on the 350's, because I assume everybody wants bigger. Side note: I corresponded with someone from eastern europe who was using the 330mm calipers with rear rotors from a Cayenne, which have less material than a front rotor should for absorbing heat and may warp or crack under hard use.

3. Hubcentricity. Any Porsche or MB rotor will not be centered on the Audi hub and will require redrilling to 112mm (Porsche). This may cause balance issues, so I believe that the correct solution is a VAG-specific rotor.

4. There was a person on here who was selling what appeared in photos to be a 345mm rotors that was the correct offset for this application. He didn't show pads in the caliper, so I have no idea whether the pads may hang over the edge of the rotor by 2.5mm (difference in radius between 350 and 345mm) They were clearly from a VAG application. If the pads do hang over slightly, it may not be much of a problem, or I could have the top arc of the pads shaved off by a machine shop.

5. AFAIK, the only applications of 345mm rotors on VAG products are B6/B7 S4, R32 (same as S4), Brembo-equipped 2001-ish S8, and Passat W8. All of these are different part numbers, except the S4/R32, which are compatible. I have a couple of photos of a B7 S4 with Cayenne calipers where a buddy of the owner said that they went right on, with correct offset and no spacers or custom work. I have purchased an extra S4 steering knuckle, and have some B6 S4 rotors at home to experiment with this combo.

6. Staggered piston sizes. Because the Cayenne has calipers on the leading edge of the rotor, and the S4 has them on the trailing edge, the way that others (including ECS)have gotten around this is to mount the right caliper on the left side and vice-versa.

The bores are staggered in size to combat uneven temperatures across the surface of a large pad, which can lead to fade, and taper problems with pads over time and lots of use. Brembo designed the staggered bore sizes that way on purpose, and I believe the best way to maintain this is to keep the caliper on the correct side, but to swap the bleeders for the connector pipe. Note: Q7 and Cayenne calipers can do this, but Touareg calipers will not- the connector pipe is internal to the Touareg caliper.

7. Lines. I'd use lines for a Brembo-equipped Audi like a 2001 S8. One can get oe or aftermarket braided lines for this application.

[pzp107]

That is exactly the stuff I wanted to hear. Thank you. I just couldnt find this info and I know I saw this before. I figured as much with the lines, figured b7 rs4 lines would work or like you said the s8 ones.

Are you saying that the b7 rs4 2 piece rotors are a solution? I just specifically remember b7 rs4 rotors and c63 amg rotors (also two Piece) as an option from some info somewhere I cant find anymore. Is the hub bore size the issue or the bolt pattern not being 5 x 112? I agree a VAG rotor would be a great solution.

I did find on another site for a different car about the caliper swapping sides but what do you mean about swapping something over between the calipers? And how will that effect the sized pistons from being in the wrong orientation for the s4 setup.

I appreciate the pictures as well.

[AddICTioN]

Great post. Thanks for sharing.

[S4_NE]

good info

[audimeister]

IIRC, RS4 rotors are 365mm, so they won't fit, although depending on offset, I have considered whether taking a larger rotor and turning it down on a lathe at a machine shop might not work, like 380mm current S8 rotors or similar. Just don't know enough about offset yet, and this avenue may be expensive.

[audimeister]

Upon rereading my post about staggered piston sizes, I can see I wasn't very clear. Swapping right to left places the staggered pistons in the opposite orientation from how they were designed to work.

If you look at the caliper, you can see the bleeders on top, and a pipe on the bottom connecting the right and left halves of the caliper. I was going to try to pull the bleeders out and swap them with the bridge pipe in order to keep the correct orientation of the staggered pistons. Hope that is more clear.

[audimeister]

RS4/6 caliper and rotor:



Touareg caliper, note different piston sizes:



Cayenne caliper on B5, with what I presume is an ECS 2 piece rotor. May belong to someone on there. Between the brakes and the wheels, I want to lick this car:



Cayenne caliper on B5, flipped so the pistons are in correct orientation. Also appears to be Cayenne rotor with beveled hat section:



Finally, Cayenne caliper on B7, with what was purportedly NO MODIFICATIONS:

[pzp107]

So where the hell are those two poeple who own those cars to answer our questions.....grrr......lol jk.

So that b7 you have pictured is an s4 345 mm rotor?

The first pic is definatly an ecs rotor. Expensive so I want to stay away from their rotors.

The cayenne rotor one I wonder what the modifications were. Whats their bolt pattern and hub bore? What are the differences between that and the b7 or b6 s4 rotor which is what I assume is what the last picture was. Great discussion so far.

[audimeister]

The B7 is a stock 345mm S4 rotor. If you wanted to loan me one of your calipers, I could test-fit and photo that combo on my extra steering knuckle off the car...

Cayenne hubs are larger than S4 hubs, so hub fit would be sloppy without some kind of centering ring. Offset is also questionable. Bolt pattern is 5x130.

[pzp107]

I didnt get the cayenne calipers yet. In the mail so far. Im gonna order a set of b6 or b7 s4 rotors from advance today and test them out and see how they do and let you know. Cheaper than sending you a caliper lol.

[manguyen]

are you using B7 rs4 lines???

[audimeister]

I didnt get the cayenne calipers yet. In the mail so far. Im gonna order a set of b6 or b7 s4 rotors from advance today and test them out and see how they do and let you know. Cheaper than sending you a caliper lol.

Cool. Post up some photos when you can, especially the edge of the rotor with pads installed.

Also, let us know if the bridge pipe is interchangeable with the bleeders. You'll need a flare nut wrench to get the pipes off.

B7 RS4 lines should work, as long as the banjo bolt is the same size.

[///M3 TO S4]

I know this has been done so I wanted to see if someone can help me out with this. I just finally picked up a set of cayenne calipers for the front on my s4. I need to know what rotors and lines I need. I am pretty sure I read b7 rs4 front rotors or c63 rotors but cant find the info again. I also think this is the same caliper as the 6 piston rs4 brakes as well is it not? What style lines would be good to know to but I think b7 rs4 lines would work. Any help would be greatly appreciate as I am lost and dont want to do trial and error and searched my brains out.

Rs4 brakes are EIGHT piston, FYI...not even close to the same caliper.

rs4 brakes are 6 piston, rs6 brakes are 8 pistons. That much I know. I just know you can use the cayenne calipers which bolt directly up to the stock b5 s4 spindles. They require use of different discs like ECS uses which I dont want to use. I remember reading somewhere mercedes c63 discs are usable. Someone has got to knwo and their help would be appreciated.

B7 RS4 brakes are 8 piston...they are the same as RS6. The rotor size Is a little different. As far as I know neither rotor will bolt up to the cayenne caliper.

You don't know if they are the same caliper and ask if they are. I try and help you and with correct information, you then negate me, tell me i'm wrong basically....then someone else backs me up stating the correct information that I said earlier. The R8, RS6, and Rs4 (B7) all use the same caliper. Wow, some people are real douches.

[pzp107]

Hey you were right, I am sorry about that. I was thinking the older model rs6 calipers I think which I believe are 6 piston. I know I saw it somewhere. But either way I appreciate the input and help. It was my bad. I am pretty sure brembo uses the same size banjo so I will try it on my bbk from my eclipse just to see since I have an extra line. I may just "borrow" a brake line from advance to to test it all out.

[///M3 TO S4]

Yup, ECS Stage 4. I payed $1400 for the kit when they first came out and on sale. I was curious on how much it will cost me for replacement rotors so I called ECS earlier this year and I was told that I need to send in the rotor hats and they will install new rotor rings with new hardware for $350 shipped.

They were very cautious in giving info/pricing since they made sure I owned the kit before I got any answers.

they are MEGA douches with their bbk's. They won't sell the brackets or ANY hardware if you don't own one allready. It isn't rocket sicence and these are nuclear weapons. I don't get why they are so greedy with this product. I'm sure these kit's arn't FLYING off the shelves, so why not make more money by selling pieces of the kit to people who can't afford to drop $1500+ on a new one?

[pzp107]

That is exactly why I want to find a great alternative to their rotors. Although I guess its about the same if I were to use b6 s4 jhm 2 piece rotors. They are expensive to and the rings would be the same in price. JHM said 150 replacement for their rings. I guess you would save 50 installing them yourself over the 350 for ecs to do theirs. I like the weight savings but its just pricey.

I am a damn engineer and I could just make my own. I don't why I don't instead of buying everyone elses overpriced stuff lol. Maybe I will, we will see.

[pzp107]

I actually looked them up already and got some quotes. They are a bit on teh pricey side by a lot actually but with a distributorship which I applied for it gives you roughly a 25 percent discount. Once I get that I can nail down a final price but I dont know how cheap it will come out really. On the plus side if the b6 s4 rotor works I just send it in or take the specs and give it to them and they will duplicate it exactly and make it is a 350mm rotor instead of 345 so it will be ideal perfect fitment. I am gonna do some research into other companies also. Who uses these guys by the way ecs? or jhm?

[pzp107]

I could design the hats myself once I got a set of rotor rings to base the design off of as well. I just dont know how much cheaper that would be.

[AddICTioN]

Some info on rotor choices... http://forums.audiworld.com/showthread.php?p=18110929

[pzp107]

I have already found this but this is for allroad fitment. I am not sure if you can follow suit as I believe they have different knuckles and different spacering otherwise. I may be wrong. The rotor he chose was not perfect either cause it wasnt center in between the caliper. But apparently it was close enough.

[audimeister]

I have already found this but this is for allroad fitment. I am not sure if you can follow suit as I believe they have different knuckles and different spacering otherwise. I may be wrong. The rotor he chose was not perfect either cause it wasnt center in between the caliper. But apparently it was close enough.

Good find, guys!

A quick check shows that the allroad uses the same rotors and calipers as the B5 S4, so we should experience the same results as he did.

It's good to see that the center bore is actually a bit tight and will center the rotor on the audi hub once machined to the correct diameter.

Upon combing through his other posts, his check on the B6 S4 rotor showed it to be too shallow of a hat. Not sure how the B7 application above works if that is the case, spacers on the caliper, maybe?

[audimeister]

One other thought with this new information-

There seem to be two offsets (really shallow- B6 S4, or really deep- C32 AMG)

Perhaps either would work, depending upon which side of the mounts the caliper is mounted to. Just don't know whether the rotor would hit something on the knuckle with the deeper offset.

An aside, the deeper offset would allow a much wider wheel choice. I'd bet I could run my 19x8.5 ET45LM reps with no spacers and a 245/35 tire...hmmmm

He doesn't mention "flipping" the caliper as far as I could see. I still think that's really important.

[audimeister]

FYI, I just picked up a nice set of calipers with hardware, but no pads from 911pcar.com for $400.

They normally sell them for $500 with pads. This could be the cheapest BBK ever!

[AddICTioN]

FYI, I just picked up a nice set of calipers with hardware, but no pads from 911pcar.com for $400.

They normally sell them for $500 with pads. This could be the cheapest BBK ever!

Nice...cayenne calipers? What rotors are you going with?

[audimeister]

Nice...cayenne calipers? What rotors are you going with?

Yes, Cayenne calipers. I have some B6 S4 rotors sitting on a shelf I'm going to try first. If they don't work, I'll get the MB rotors.

[jrock]

FYI, I just picked up a nice set of calipers with hardware, but no pads from 911pcar.com for $400.

They normally sell them for $500 with pads. This could be the cheapest BBK ever!

That company is also the largest seller on ebay too...

[rharris]

Hey guys,

I've got an extra set of MB rotors if anyone is interested. I also have some other options including a custom hat/350mm rotor ring combo that I just finished developing.

[audimeister]

I was just monkeying around with my B6 S4 rotor and the spare knuckle. It only clears a couple places (top and bottom) on the knuckle by 2mm, give or take. A deeper rotor (like the MB) may require a bit of grinding...

Also discovered that a CLK55/SLK55 is the same as the C32 AMG rotor, but floating.

[AddICTioN]

I was just monkeying around with my B6 S4 rotor and the spare knuckle. It only clears a couple places (top and bottom) on the knuckle by 2mm, give or take. A deeper rotor (like the MB) may require a bit or grinding...

Also discovered that a CLK55/SLK55 is the same as the C32 AMG rotor, but floating.

I was told that the caliper has to be grinned a bit at the points where is bolts up to the spindle about 3/16ths, maybe even less. And you have to grind about 1/8 off of the spindle itself at one of the mounting points, cause it won't clear the caliper...using B6 S4 rotor's.

[AddICTioN]

Hey guys,

I've got an extra set of MB rotors if anyone is interested. I also have some other options including a custom hat/350mm rotor ring combo that I just finished developing.

Any pics?

[pzp107]

I got my calipers today and can attest to their mammoth size. They are huge. I see the sequential sized pistons as well. The bleeder screws and crossover pipe seem to be the same thread size. Havent dissasembled them to see. Maybe if I decide to do them in blue I will. Ahh what the hell I will verify 100 percent this weekend. If you are able to do this you will be able to keep the right side cayenne caliper on your right side as well and keep the correct trailing sizes of pistons, meaning you will be able to go from small piston all the way to large in that order from where the rotor moves forward. As for rotors I am worried about working out correctly. I am going to get the mb s4 and stock cayenne rotors and test it all out. Obviously hub bore and lug orientation will have to be fixed on all except for s4 rotor. I know it says it seems to be too shallow. I dont mind spacing the caliper out. I will not space the rotor though. I wish I was like audimeister and had a spare knuckle to mess with this crap and take actual measurements.

[jibberjive]

Subscribed. Great thread!

[audimeister]

My calipers are supposed to get here today, but I'm headed to Austin for the weekend, so will have to wait until Sunday night to test fit with S4 rotors. Stay tuned!

[audimeister]

OK, so my calipers showed up before lunch, and I did a little test-fit before hitting the road.

They WILL NOT work with B6/B7 S4 rotors. Based on a few quick and dirty measurements, the ideal underhat-to-centerline of the rotor would be ~ 29.5mm. The S4 rotor is 23, so it sits too far outboard to work.

Based on the AW posts, I was able to calculate this measurement from the rotors that he measured:

B6/7 S4 23mm
C32 AMG 27.6mm
ML55 29.6mm
ML430 29.8mm
'01 S8 38.3mm
Cayenne 44mm

Based on the above, one might think the ML55 rotor is the one, but remember that there are clearance issues between the rotor and the steering knuckle.

Also, one may be able to get the S4 rotors to work by milling material from several places- the hub, inside of hat, the caliper or knuckle mounting eyelets, but I am unwilling to make those parts weaker on my car.

So...the C32 may be the best low-buck compromise rotor for this application, and that is what I will be using. Would still like to see how those ML rotors fit, though.

[audimeister]

Quick update- the bleeders and the bridge pipe ARE interchangeable, which allows the calipers to be flipped.

[pzp107]

damn you beat me to it. I did it before easter but then went home and didnt have a comp to put it up with lol. good find either way.