Brake Upgrade B6, B7 S4 +

[Kevin C]

I have been running the B6-B7 S4 setup for a few years and they have been great as in 90+ mph stops on a downgrade with no fade. The one wishlist thing was to drop a bit of weight from the setup. JHM rotors wenton sale so I picked a set up. Super nice looking pieces and the lose about 10lbs per side and are drop in.

https://jhmotorsports.com/front-roto...4-2004-up.html

The logo is also small so I'm not turning my car into a billboard (I'm talking about you ECS!).

OK, I commited to nice rotors, why not some light weight calipers? The Audi 345 mm calipers are surprising pricey, even used (8R0615107G, 8R0615108G) @ about $490 each from a discount dealer. Ebay prices used are in the $300-500 range for a set. Looking around a bit the Porsche versions are about $285 each and powder coated black. Looks to be the same part for only a bit more than some scalpers are trying to get for them new. Even Car-Part.com seems pricey.

Last night I went for it and bought a set (95B-615-123-F & 95B-615-124-F).

A bit of a markup over the dealer price.

https://www.fcpeuro.com/products/por...che-95b615124f

Original Thread:

https://www.audizine.com/forum/showt...ild-BBK-thread

Now its a just a matter of sourcing pads and lines. Looking for OEM style on the lines and a decent street pad. Should be fun. I will swap the over when I swap in the summer tires.

20240401_201858.jpg

[ye1low]

Curious why you did not go the 18z/17z route? Far cheaper and probably a tad better in performance. I'm currently building my 18z front and S4 rear setup right now. I'm just left to pull out my powder coating gun and bake them. I'll post pics during and after they are installed.

[Kevin C]

Not sure the 18Z is cheaper if you want to run 2 piece rotors and if your sourcing new calipers. Most of the 18Z setups I have seen are using single piece rotors that weigh a lot more (this setup drops about 10lbs per rotor and 10 per caliper for about a 40 lb total savings).

What rotors are you running?

As far as performance this is so far past stock I'm not concerned about incremental changes past that. Right now on just the S4 setup I can stop from 100 mph with zero fade. I'm sure the directional vaned two piece rotors will add a bit more margin past that.

How did I choose? Originally I just planned on doing a rotor upgrade to reduce rotational mass. Once I got them I was ,heck I should just go for it and get some calipers. I saw the the OEM Porsche parts were pretty reasonable new so I just went for it.

One thing that I like is I can mix and match the S4 parts. Next winter if I don't want to run my fancy 2 piece rotors (rotor rust is real when you have endless wet weather. ) I can just put the stock S4 rotors back on running the same calipers.

I'm sure your setup is awesome and from a looks standpoint is hard to beat.

[ye1low]

I'm running B8.5 S4 rotors (Brembo 09.B970.11, 4G0615301) rotors. They are insanely heavy! That's the only drawback to the setup. If I ever win the lottery or get a better paying job I would love to go with two pieces. Even the S4 solid rear rotors are heavy. I went with new 18Z and new S4 calipers. Once I'm done everything hanging off the spindles will be new hardware. To be honest I'm coming from 288 front and 245 rears. ANYTHING I put on there will be an upgrade. My new S4 rears are bigger than my stock fronts.

[Kevin C]

My bank account needs a lottery win to look good again. Seriously your setup sound great. I may have to get a powder coating setup.

I looked at enough writeups and varying opinions that I was just about in frozen mode on what to get. Hopefully this is not a mistake. That and I have never messed around with 2 piece rotors and figured I would give it a shot. I have the B6 / B7 S4 rears but they are vented ( I assumed your would be). I also swapped in the S4 aluminum knuckles.

It is funny to have the rears end up the same size as the stock A4 B6 fronts.

Fun stuff.... I just need to work on brake lines and pads.

[ye1low]

I may have to get a powder coating setup.

Do it. They are cheap. I've owned the Harbor freight one for almost a decade now and it works great. Eastwood makes one now as well. They both perform equally well. I don't powder coat often enough to justify a spare used oven nor do I have the space for it. I just throw them in my regular oven when my wife isn't at home.

I agonized for years on what setup I wanted. I was going to go the full S4 route, then 4 pots 1LE, then eventually I settled on the 18z mainly because I've never owned 6 piston calipers before and it allows me to run 345 rotors.

I'm an Akebono fan boy but sadly they don't make them for the 18z/17z calipers. I don't know what magic they put in them but they put out almost zero dust, no noise and I've never had to change a single set once I install them. They last forever. I'm certain there are better pads for track and heavy driving but I don't do any of that. I just like my calipers and rims to stay as clean as possible for as long as possible.

I totally forgot about the S4 knuckles!!! Thanks for reminding me about that option. Not sure about your calipers but I went with the RS4 lines. Stoptech 950.33005 to be exact. I'm trying to hunt down the ABS / Brake line brackets now rather than go the zip tie route.

[Mike Tries]

I love my EBC Yellowstuff pads. They handle track day abuse on quasi-track rubber. They work in all temperatures, too, and won't murder your rotors for using them in the cold.

[EuroxS4]

I had 17Z on my a4 avant. Stopped great, I have benz e350 diesel rotors I was using. But they were heavy alot of unsprung weight. I think 2 piece rotors with alloy hats is the way to do. The plus side to the 17z was that they fit under the stock 17 inch sport wheels.

At this time the 17z will get rebuilt and put on the next avant once the engine swap is completed.

[seanf86]

I have been running the B6-B7 S4 setup for a few years and they have been great as in 90+ mph stops on a downgrade with no fade. The one wishlist thing was to drop a bit of weight from the setup. JHM rotors wenton sale so I picked a set up. Super nice looking pieces and the lose about 10lbs per side and are drop in.

https://jhmotorsports.com/front-roto...4-2004-up.html

The logo is also small so I'm not turning my car into a billboard (I'm talking about you ECS!).

OK, I commited to nice rotors, why not some light weight calipers? The Audi 345 mm calipers are surprising pricey, even used (8R0615107G, 8R0615108G) @ about $490 each from a discount dealer. Ebay prices used are in the $300-500 range for a set. Looking around a bit the Porsche versions are about $285 each and powder coated black. Looks to be the same part for only a bit more than some scalpers are trying to get for them new. Even Car-Part.com seems pricey.

Last night I went for it and bought a set (95B-615-123-F & 95B-615-124-F).

A bit of a markup over the dealer price.

https://www.fcpeuro.com/products/por...che-95b615124f

Original Thread:

https://www.audizine.com/forum/showt...ild-BBK-thread

Now its a just a matter of sourcing pads and lines. Looking for OEM style on the lines and a decent street pad. Should be fun. I will swap the over when I swap in the summer tires.

20240401_201858.jpg

I used 94 Jetta 2.0 front hoses for my 320mm Q5 Brembo swap, I also found the number for the BMW wear sensor wire clips ECS includes in their kit that clip to the brake hose since you can't connect them in the factory spot behind the knuckle.

The Jetta hose may be an inch too long, its shorter than the B8 hose and I read somewhere that one manufacturer of the "kits" being sold online used mk3 brake hoses so I went out on a limb and bought some.

[ye1low]

I also found the number for the BMW wear sensor wire clips ECS includes in their kit that clip to the brake hose since you can't connect them in the factory spot behind the knuckle.

That's good news. Mind posting part #s if you have them? It really helps others that are digging through these threads trying to build the similar setups.

[Kevin C]

Finished up ordering the small parts.

Pads: Akebono ceramic brake pads EUR1663 $92.00 https://www.ecstuning.com/b-akebono-...t/eur1663~ake/
ECS brake hoses for the B6 upgrade using the saem calipers. On sale for $65.44 https://www.ecstuning.com/b-ecs-part.../014546ecs01a/
a BMW clip for the pad sensor wire 34356779356 https://www.ecstuning.com/b-genuine-...p/34356779356/
Caliper Bolts: N90876802 https://www.ecstuning.com/b-genuine-...ach/n90876802/
A set of sensor wires: 8K0615121 https://www.ecstuning.com/MyAccount/...der-849511494/

This should keep me out of trouble... With any luck I will get a break from work and be able to take some time out and work on the car.

That should be all the parts I need. I have heard good things about the Akebono ceramic brake pads.

[Spike00513]

there you go. There's performance pads out there.

lot of folks like Akebono Euro Ceramic. It works. And is supposed to last longer, less dust, not eating the rotor up as much.

junkyard source would be hit or miss. Prices change, inventory doesn't get listed. Drive far get there spend all day looking just to find out they don't have.
Don't know if it's what it used to be.
Used to be option of Pick N Pull. The Pick N Pull closed.
Asked for a quote on a spindle. New $230. Man said $400+. Used. Unknown history. Not known if straight or bent.

I know depending on vehicle StopTech Cryo rotor is regarded as better than non cryo.
While you're at it might even be possible to drop the discs off for cryo treatment if it's not already. Shouldn't cost that much. At minimum could make them last longer which is important at this price.

[Kevin C]

Interesting idea on the Cryo.... This is another option:

https://www.coherent.com/news/blog/ehla-cladding

A group of engineers at Fraunhofer Institute for Laser Technology ILT and RWTH Aachen University (both in Aachen, Germany) have developed a new laser material deposition process that offers the solution. Their method, called Extreme High-speed Laser Material Deposition (or its German acronym EHLA), introduces some key innovations into laser cladding.

Like traditional LMD, EHLA sprays powdered metal at the surface of the disc brake, and melts both with a high-power diode laser (HighLight DL series). But, EHLA uses a custom-designed nozzle that allows the cladding powder to be melted “on-the-fly" in the laser beam before reaching the part surface. So, liquid droplets land on the part in a very thin layer of melted grey cast iron. All this metal then rapidly resolidifies to form a thin coating.

No rotor corrosion and super wear resistant. It might need special brake pads.



Someday this may go mainstream.

[ye1low]

I work in R&D technology group for one of the top three oil and gas service companies in the world here in Houston. We routinely use that process for our drill bits and downhole motors. It provides surface hardening for our high wear areas. Good luck getting the machine time quoted for just a pair of rotors. You might as well buy another B6 to go with the quote.
I'm in the wrong buisness....

[Spike00513]

Interesting idea on the Cryo.... This is another option:

https://www.coherent.com/news/blog/ehla-cladding



No rotor corrosion and super wear resistant. It might need special brake pads.



Someday this may go mainstream.

ima have to read more into that to try and fully understand, looks interesting

looks like the laser is on the disc but nowhere else that corrosion tends to happen due to the pad only wiping the disc and nowhere else
with other prevention already in existence such as Zimmerman rotors coming zinc coated

rotors wear, so IDK if the hardness applied will still eventually get worn through and off
if it creates an undesireable friction coefficient, or prevents material layer transfer from the pad during bed-in.

who knows like you said maybe stronger pads and way to achieve similar higher performance to carbon rotors without the crazy cost.
Looks almost like coatings they use on drill bits but bigger scale on rotors.

company claims a concern is particulate emissions, brake dust floating in the air on the road (which is true)
which today probably comes from a pad wearing more than a rotor but I guess the tech isn't finished and they still may be working on figuring the rest of it out or not divulging it.
Plus not well known so no mandate to have it yet.

Maybe hardened pads, hardened rotors, less friction, compensate with more and bigger and costlier parts
or take the DEF route mount a pig pee injector and see what happens. Keep the bottle full or it triggers CEL, use it to wash the dust down the gutter.

Could mount bananas in the caliper. It's biodegradeable.
none of this pretend banana brakes.

I work in R&D technology group for one of the top three oil and gas service companies in the world here in Houston. We routinely use that process for our drill bits and downhole motors. It provides surface hardening for our high wear areas. Good luck getting the machine time quoted for just a pair of rotors. You might as well buy another B6 to go with the quote.
I'm in the wrong buisness....

Same here, I work in R&D. We have a welding and cutting apps lab for laser testing and I have access to high power lasers that we use to process metal. It's possible... But I would need to get some buy in. They are super strict about protocol and what we can do in the lab (who knew that lasers could be dangerous?). It's a dream. Not cost effective but it still seems interesting.

You know what you must do. Bring your rotors to work on Saturday. And whatever other upgrades you're able to do.

and of course let us know (if that is allowable)

Real world testing on your vehicle would provide value to the company.

----

what if...
what if the banana brake pad is diamond-coated

[Kevin C]

Same here, I work in R&D. We have a welding and cutting apps lab for laser testing and I have access to high power lasers that we use to process metal. It's possible... But I would need to get some buy in. They are super strict about protocol and what we can do in the lab (who knew that lasers could be dangerous?). It's a dream. Not cost effective but it still seems interesting.

[ye1low]

So many dreams and wishlists.... not enough money. (or weekends to get it all done)
Induction hardening is another process that is realitively inexpensive and would yield great results for this application too.

[Kevin C]

So many dreams and wishlists.... not enough money. (or weekends to get it all done)
Induction hardening is another process that is relatively inexpensive and would yield great results for this application too.

I know..... I see and use some crazy tech at work and the thought is always : How can I use this on my car? Just to be clear, not the laser weapons, the 3D printing using a variable shape laser beam and using the the optical coatings we spec to upgrade headlights. As far as coatings go, how hard could it be to make your own PVD system? Plans are on Youtube, used parts are available on Ebay.

Then there is the reality of keeping up on chores and working for a living and finding a place for anything that I build.

[oaybar007]

I'm finally getting around to getting my S4 front and rear brakes on. I had rebuilt calipers from a 2004 S4 back in 2018 and refinished them. I really wanted to go with the JHM rotors as well but the price was just too much. At the same time, you are getting directional vanes and a proper lightweight rotor. I'm not looking forward to the added weight of the b6 s4 front and rears with zimmerman rotors. I run 18lb OZ wheels and was enjoying that weight loss for years. Now I'm gaining it back and then some with the S4 brake setup.

[Mike Tries]

At the same time, you are getting directional vanes and a proper lightweight rotor. I'm not looking forward to the added weight of the b6 s4 front and rears with zimmerman rotors. I run 18lb OZ wheels and was enjoying that weight loss for years. Now I'm gaining it back and then some with the S4 brake setup.

I know that in principle, rotational mass is bad for driving dynamics. But can you really tell? This is one of those things I would assume shows up in lap times more than in every-day driving. I'm not skeptical, I just wonder how it actually manifests in every-day driving dynamics.

Also, Ellicott City, eh? I work near there. I'll keep an eye out for that bright red A4 of yours.

[Kevin C]

I hear you on the price. The sale helped a tiny bit but its still a chunk of change.

[Kevin C]

When I went to the bigger brakes I felt the extra weight was very noticeable, but over time I got used to it and that just the way the car is. I cant wait to get the lighter parts on. I may have a bias because I just dropped $700 or rotors and $580 on a set of calipers. The pads should be in next week, I pick up the calipers tonight.

[Mike Tries]

What pads did you get, Kevin?

[Kevin C]

Mike, I got Akebono ceramic brake pads EUR1663 $92.00 Seems like an OK choice. Nothing fancy.

Calipers just showed up, waiting on pads and hoses:

20240410_183441.jpg

[BumblebVR6]

My current setup. Alcons w/ 355mm front rotors and 300mm rear S4 setup:





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[BumblebVR6]

Will probably throw these on in the future from my old sedan.





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[ye1low]

Looks awesome! Glad they went on without an ohhh-F#$K!! moment. I still have parts sitting in boxes and fear I might run into that regardless of how much I mentally planned...
Were those ECS rear rotors non-directional?

[BumblebVR6]

Looks awesome! Glad they went on without an ohhh-F#$K!! moment. I still have parts sitting in boxes and fear I might run into that regardless of how much I mentally planned...
Were those ECS rear rotors non-directional?

I believe they were directional since they're installed the way they are. Most slotted and drilled rotors are oriented this way and usually shipped w/ stickers indicating location.

[ye1low]

I've always installed my rotors with the slots towards the back of the car although that's a cosmetic thing. The defining factor is the internal slot direction. Those should point to the rear and in some cases the surface slots are sometimes machined opposite to that (and sometimes the internal slots don't have any curvature to them and in that case it does't matter how the surface slots are machined).

I don't honestly know how much of a difference all that really makes on a street car.

[BumblebVR6]

I've always installed my rotors with the slots towards the back of the car although that's a cosmetic thing. The defining factor is the internal slot direction. Those should point to the rear and in some cases the surface slots are sometimes machined opposite to that (and sometimes the internal slots don't have any curvature to them and in that case it does't matter how the surface slots are machined).

I don't honestly know how much of a difference all that really makes on a street car.

Internal vane design and orientation is the key. I’ve ran Girodisc, Stoptech, ECS rotors and have always found the location stickers on them to be correct as far as cooling efficiency goes.

https://girodisc.com/technical-info/


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[Kevin C]

My quick update. I have a few hundred miles on the new brakes. The pedal feel is good and the reduction in sprung weight is nice. Basically, its less sprung weight than the tiny stock 1.8T brakes but you get 345mm rotors and four piston calipers.

The bad? after a couple of hundred miles the JHM rotors developed a pulsing. I did a standard brake shoe bed in and everything seemed fine. After about a week I noticed a super slight pedal vibration, if I braked at highway speeds. I did another bed in and it got worse, as in don't use the brakes at any speed above 65 mph.

I had heard this could be an issue with the JHM rotors and certain pads and there seems to be a compatibility issue with the zinc coating and some pads.

From JHM:

JH Motorsports does not recommend using EBC brake pads with our 2-piece lightweight rotors. Customer have reported and we have found EBC pads leave excessive pad deposits that can cause brake pulsation. Many EBC pads have a break in coating that reacts with the zinc plating used on our rotors

Mine has it bad just using a not all that fancy set of Akebono pads. I'm going to take a look at it this weekend. I'll get some measurement on runout and thickness this weekend to see what's going on. It looks like the ECS two piece rotors might be a better setup.



Screenshot 2024-04-21 195343brakes.jpg

[Mike Tries]

Can you lightly sand the surface of the rotors to clean them up and then rebed them?

[Kevin C]

Can you lightly sand the surface of the rotors to clean them up and then rebed them?

Yes... But before I touch them I want to get a couple of measurements. If they have a runout problem and I need to return them I don't want to explain that I put a DA to them.

I also found this from Brembo:

https://www.racetechnologies.com/art...rating%20heat.

The discs are delivered with a thin zinc coating to prevent corrosion. Prior to beginning the bedding procedure, this plating must be removed from the braking surfaces by driving the car slowly (under 30mph) and performing very light brake applications in order to remove the plating without generating heat. With too much heat or pedal pressure, this plating can be deposited unevenly on the disc, and impregnated into the pad, further increasing the likelihood of judder development. Once a visual inspection of the braking surfaces confirms that the plating has been evenly removed, begin with the bedding procedure as specified below.

The JHM disks seem to have a somewhat thick zinc coating, its still super shiny even after a week and half of driving. According to Brembo I should not have bedded my pads in yet. The disks did not come with any special instructions.

[ye1low]

I'm really curious if its the zinc or runout either from warped rotor or excessive lateral runout on your hub. I find it really hard that those Akebonos are to blame. Either way, that's a super huge bummer for all that time and effort to end up with an outcome like this. Sorry to hear it man.

[Kevin C]

I'm really curious if its the zinc or runout either from warped rotor or excessive lateral runout on your hub. I find it really hard that those Akebonos are to blame. Either way, that's a super huge bummer for all that time and effort to end up with an outcome like this. Sorry to hear it man.

Me too! It feels like some buildup. The upside is the cast iron is just starting to show through the zinc so it should be easy to just clean up the pads a bit (same with the rotors ) and start fresh. I also read that other manufactures of plated rotors recommend starting with a used set of pads to break in the plated rotors. Once they are through the plating the new pads get put in. Glad I have my used set of Brembo one piece rotors to use as a backup (and the S4 calipers to match). A coworker wanted them for his golf, cause you cant have too much braking on a Diesel VW. I was like no, I'm not giving those away.

[Tahoe3.0]

I’ve been running your new setup for a couple of years, once you sort out your vibration you will definitely enjoy it. I had the same frustrations with my fronts warping quickly with some cheap slotted rotors (r1 concepts) and ebc redstuff. Replaced with Brembo blank rotors and some macan oem pads and all has been well up front.

[Kevin C]

Sunday I cleaned the garage and p[ulled the car in. In the interest of science I measured the rotors for thickness variation. The left side rotor had about .002" and the right had about .0022", definitely too much. The pads also had smears of zinc embedded in them, and the up close the rotors looked really ugly.

I dressed the pads down using 80 grit on a surface plate and did the same to the rotors using a precision flat with 80 grit. The pads cleaned up in seconds. The left rotor was easy and it took less than ten minutes of hand work to get it to under .0005". The right rotor seemed to have a combination of deposits and metal thickness variation. After rework it came in at .001". From what I have read thats the high side of what you want. I spend an hour with a precision ground flat, micrometer and stick on abrasive sheet to get it to about .0007". Not ideal but in spec. It also showed that the deposits are easy to remove but to change any thickness variation in the metal takes a lot of work.

The test drive seemed OK, braking was much smoother with no shudder or torque variation. I went back to bedding the pads in and got one stop that started to do the same thing and then smoothed out. I will know if this works once I get some miles on them. The entire issue seems to be getting the pads bedded in with the zinc coating. JHM tech said they had good results using Hawk pads, EBC is a problem and it appears the the Akebono pads don't like it either. I'm sure once I get completely past the plating it will be fine, this was new to me.

Rotor up close after removal
rotor_ugly.jpg

Pad with smeared metal
padmetal.jpg

Pad after cleaning
cleanpad.jpg

Rotor Measurement (8 locations per rotor)
measurerotor.jpg

[Mike Tries]

Science! Good write-up--this was interesting. I hope it all stays smooth for you from now on!

[Kevin C]

Science! Good write-up--this was interesting. I hope it all stays smooth for you from now on!

Thanks. I was curious and I have never seen any measurements on rotor thickness variation that included trying to remove it. At this point I'm a bit wary of zinc coatings on the friction surface. I know they can be made to work,but its not a nearly as easy as I initially expected.

[Mike Tries]

Thanks. I was curious and I have never seen any measurements on rotor thickness variation that included trying to remove it. At this point I'm a bit wary of zinc coatings on the friction surface. I know they can be made to work,but its not a nearly as easy as I initially expected.

I had a set of rotors on my Miata that came with a Zinc coating. The Hawk DTC-60s chewed right through that Zinc like it wasn't there. It didn't stand a chance. So maybe it really does come down to the pad selection.