Front brake quasi OEM mod--more show than go fun; feasible on all D3's (rotor sizes vary)
03-05-2008, 10:17 PM
#1
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Thread Starter
Front brake quasi OEM mod--more show than go fun; feasible on all D3's (rotor sizes vary)
With my brake pad warning light coming on recently, and seeing covert4.2's ad for new drilled and slotted front rotors, I figured I would take the plunge. Along the way, I explored the vagaries of D3 brakes, both regular 4.2's and S8's/W12's. The elevator speech of what you see here are STOCK calipers with a paint job and an S8 trim piece only, married up to some OEM drilled rotors that you can buy aftermarket and a decent set of aftermarket D3 pads.
Basic before and after shots at a distance:
After:
<img src="http://pictureposter.audiworld.com/26081/new_brakes_full_wheel_small_file.jpg">
Picture 1
Before:
<img src="http://pictureposter.audiworld.com/26081/old_brakes_full_wheel_small_file.jpg">
Picture 2
Pads: If any of you have looked around for brake pads for a D3, you know it isn't easy. In general, only the OEM pads can be found without turning the world upside down. There are a few listings, but not many. As one of several examples, ecs tuning sells the OEM pad sets, though not for that much off dealer pricing apparently. If on the other hand you own a W12 or S8, good luck. I eventually found a W12 listing or two, but the S8 is still too new to find any. Same situation with the C6 S6.
Well first thing to know there is the W12 and S8 both use a 385mm x 36mm front rotor. This is over 15"! It weighs well over 20 pounds too! Similarly, I think they use the same brake pad: 4E0 698 151K is the W12 number. The 4.2's use a 360 x 34mm front rotor, with a very close pad set part number, 4E0 698 151J (mid 2005 forward), or without the J suffix before that. Well, the fun starts here. When I finally found a name brand pad with a W12 listing--EBC Brakes in the UK in either "Red Stuff" (Ceramic streets) or "Yellow Stuff" (light track), I found their part numbers were the same for 4.2's and W12's. Hmmm.
I ordered up a set of the Red Stuff from a U.S. on line source to check it out. Priced very similarly to ecs tuning's OEM pads. On arrival they sure looked right so I put them aside pending install. Then I started getting some pad chatter at slow stops by chance and before long the wear light came on. Next thing I knew, covert4.2's new rotors hit the market when he went to a nice big brakes set up. Separately, I ordered a set of OEM pads so I could reverse the mods in the future. Side note: I plan to get my original rotors ground too and then store them to re use too if ever desired. Meanwhile, ecs had the wrong W12 pad listing on their site--since quickly fixed when I pointed it out. That faulty reference led them to send me the 4.2 pads (the early ones w/ no suffix). Comparing those to the EBC's I now had in hand, I can report no difference at all in backing plate shape, pad material sizing, wear sensor wire or otherwise. Just different advertised compound. Red backing plate for the EBC's, and a break-in material coating on the pad that seems kind of like rubberized fine sandpaper grit material. A week later, I got the corrected W12 pads (again, same as S8 I expect). Well, now I saw a slight difference. Backing plate, general appearance and wire connection all the same again so that was good. But, the W12 pad face was slightly SMALLER. Say what? When I lined them up really carefully, the pad material is about 4/32" smaller from the inside of the rotor toward the outside edge of the rotor. The width side to side is the same. And, even though the W12/S8 outer rotor diameter is somewhat larger, the outside curve of the pad seems unchanged. Pads still seemed interchangeable, though I began to wonder why Audi would have changed this. For reference, either set of pads fits cleanly on the running face of the rotors if you just set them there as a loose part. At first my sense was the 385mm pad didn't get quite so close to the hat on the inside, and maybe they didn't want to have the pad cut the disk away there as much. Yet, the rotor is a boat anchor and it looked very robust in this area. As you will see later below in the pics (Picture 6), it turns out the 4.2 pads run out that 1/8 inch closer to the OUTSIDE of the rotor. It still hits the rotor in full, but reduces substantially that "lip" you often see on worn rotors.
For you data hounds out there, I calculated the swept area on a W12/S8 front rotor with OEM pads for the application as about 173.78 sq. inches per rotor, while I got about 175.25 sq. inches when using the 4.2 pad spec, an increase in swept area of about 1.56% per front rotor. Small, but can be seen. I headed off in the 4.2 pad direction using the EBC Red Stuff.
Rotors: More frustration. Unobtainium in a W12/S8/S6 application from companies like Brembo, DBA, EBC or others. Found a BrakeWorld listing once for either "Brembo's" or "Disc Italia's" and e mailed them. But I wasn't convinced it was for real, especially the Brembo's since Brembo itself had no listing for the D3 at all other than a sport brakes kit based on the same basic set up used in the C5 RS6. Then covert4.2's ad popped up. He sent pics and I realized then they are really OEM Audi rotors that have been drilled and slotted. The rotors have the Audi part number laser engraved on them along the edge (4E0 615 301K) and are marked "Made in England", though separately they allude simply to "Germany." Later when I dismounted my stock original OEM rotors and wire brushed them, I found the identical laser markings and text. Thus, supposed BrakeWorld Brembo's = drilled OEM's. Audi might get the disk blanks from Brembo though. Separately covert4.2 got some Disc Italia rears for his set up, which again seemed to have the Audi OEM part numbers and even packaging. Lest you think this is just a W12/S8 write up, they sell these drilled and slotted rotors for 4.2's too. Pricing nets to a couple hundred dollar premium for a more nicely finished set of OEM front rotors.
Calipers and appearance: When I bought the car and was amazed by the design, the drive, the power right now, the goodies and the general finish, I always thought the one let down was the brake finishing, and more so in front. Just not up to the standard of the car. Somewhat sloppy casting of the caliper, lowly manufacturing obvious numbers ink stamped on. Dumb, undersized looking pad spring retainer that had unsightly surface rust (on a California car no less!). No nice paint details. And rotors that look right off my wife's Sienna, just bigger. Old C5 4.2 with HP2's looked classier honestly, and their pad retainer system with the top quick load set up looked like it meant more serious business. Sure mega size rotors on my car, but with hats in plain sight through the wheels with rust splotches. See Picture 5, and I had already painted pad spring retainer by then. Were I Audi, I would have been rejecting parts from my supplier, but I guess not in cost cutting world. At first, I went to work last fall with some catalyst type brake caliper paint. Got it from Tire Rack. I used silver for the calipers and black for the caliper carrier (bracket) and pad retainer. Didn't touch the rotor hats though. Somewhat time consuming--basically a weekend off and on with brakes disassembled but fluid lines still connected to the car. Several coats to get a deep finish, with some drying time and finish sanding to reduce brush marks. Six months later, I can report the paint holds up w/out any issues--very tough, color fast, no heat related burning or discoloration, etc. Most pictures I post here make the silver look too glossy due to the flash; Picture 5 that I took a bit off angle is a more natural representation of the silver finish--sort of an eggshell.
Pad spring retainer: One of the ho hum things on the current D3 brakes. Looks wimpy. Then I saw the S8 retainer. Really dressed the whole thing up on an S8 (or S6). Gave me an idea. I wasn't wild about the S8 branding on a W12--the sport parallelogram is cool, but S8s and W12's are just different, and I'm not a "pretender" type with badging either. That will take an artist and high temp paints to customize, so for now I left it w/ S8 markings. Might mean the fender W12 logos go. Retainers are pricy by the way; low volume S8/S6 only part.
Total time for job: 80% I would estimate was on the caliper and carrier painting previously. Pads are maybe an hour, assuming a bit of cleaning but not going wild cleaning up wheels, suspension bits, etc. Unremarkable tools. Reinstalling the pad spring retainer is the hardest task, whether original OEM spec or the S8 substitute. Still just takes careful prying with a screwdriver with holding pressure on the clip. Removing the carrier bolts to get the rotors off and later retorquing them takes some effort--torque is well over 100 ft. lbs.--and clearance is awkward if you aren't using a lift. I just used a floor jack.
Performance disclaimers: Okay, its all show, no real go. You could argue it a bit on the drillings, but I won't. These are machine drilled too, rather than factory cast in. Could mean stress cracks later. Slotting does help clean pads and rotor face. Some say slotting or drilling makes audible noise during braking. I hear none at all; note I do have the double paned glass though and D3's are heavily insulated to start. You all probably know these are two pot, two pad rotors with floating pins, not two pot, 4 pad rotors like the old C5 4.2's and D2's, or 4 pots or more for C5 RS6's and the current RS4's. But, relative to the older C5 or D2 4 pad HP2's or the C5 RS6 Brembos, the pad area of these is far bigger, and people came to realize those older brakes really have undersized pads that tend to cook. The D3 overall pad sizing is a plus here. Also, while the disks are real boat anchors, the calipers are aluminum shells. Forgettably called FNR42 AL's (FNR = new floating frame, AL = Aluminum). By contrast, here the old HP2's were the cast iron boat anchors of yore. More trivia: turns out the 385mm rotors have directional vaning internally. BUT, they don't make left and right rotors. Thus on one side of the car the "leading edge" of the directional vanes is at the bottom. On the other side it is effectively at the top. Both old and new rotors are identical that way. The drilling and slotting was done for left and right hand side positioning. That means in practice some of the drill holes penetrated a bit of the internal vaning castings.
More pics:
Close up of new set up:
<img src="http://pictureposter.audiworld.com/26081/rotor_and_caliper_as_installed_small_file.jpg">
Picture 3
Even closer:
<img src="http://pictureposter.audiworld.com/26081/new_brakes_most_close_up_small_file.jpg">
Picture 4
Old set up with wheel off:
<img src="http://pictureposter.audiworld.com/26081/old_brake_set_up_small_file.jpg">
Picture 5
Close up of pad swept area after some initial use:
<img src="http://pictureposter.audiworld.com/26081/new_brake_set_up_rotor_swept_area_small_file.jpg">
Picture 6
New (4.2 size) vs. old (W12 (S8) size) pads placed on rotor w/ outer pad edge flush to outer rotor edge. Note number printed on OEM pad does NOT match the number on the pad box I put in the text above; inside and outside pads apparently have different part subnumbers on them:
<img src="http://pictureposter.audiworld.com/26081/pad_sizing_small_file.jpg">
Picture 7
Rears are still to go, though covert4.2 already posted a very similar set up. Mine will have the Red Stuff pads and a black painted carrier bracket spiff. Rear calipers themselves are better finshed that the fronts.
Closing side fender shot (brake trim and fender logo inconsistency noted):
<img src="http://pictureposter.audiworld.com/26081/fender_side_view_small_file.jpg">
Picture 8
Basic before and after shots at a distance:
After:
<img src="http://pictureposter.audiworld.com/26081/new_brakes_full_wheel_small_file.jpg">
Picture 1
Before:
<img src="http://pictureposter.audiworld.com/26081/old_brakes_full_wheel_small_file.jpg">
Picture 2
Pads: If any of you have looked around for brake pads for a D3, you know it isn't easy. In general, only the OEM pads can be found without turning the world upside down. There are a few listings, but not many. As one of several examples, ecs tuning sells the OEM pad sets, though not for that much off dealer pricing apparently. If on the other hand you own a W12 or S8, good luck. I eventually found a W12 listing or two, but the S8 is still too new to find any. Same situation with the C6 S6.
Well first thing to know there is the W12 and S8 both use a 385mm x 36mm front rotor. This is over 15"! It weighs well over 20 pounds too! Similarly, I think they use the same brake pad: 4E0 698 151K is the W12 number. The 4.2's use a 360 x 34mm front rotor, with a very close pad set part number, 4E0 698 151J (mid 2005 forward), or without the J suffix before that. Well, the fun starts here. When I finally found a name brand pad with a W12 listing--EBC Brakes in the UK in either "Red Stuff" (Ceramic streets) or "Yellow Stuff" (light track), I found their part numbers were the same for 4.2's and W12's. Hmmm.
I ordered up a set of the Red Stuff from a U.S. on line source to check it out. Priced very similarly to ecs tuning's OEM pads. On arrival they sure looked right so I put them aside pending install. Then I started getting some pad chatter at slow stops by chance and before long the wear light came on. Next thing I knew, covert4.2's new rotors hit the market when he went to a nice big brakes set up. Separately, I ordered a set of OEM pads so I could reverse the mods in the future. Side note: I plan to get my original rotors ground too and then store them to re use too if ever desired. Meanwhile, ecs had the wrong W12 pad listing on their site--since quickly fixed when I pointed it out. That faulty reference led them to send me the 4.2 pads (the early ones w/ no suffix). Comparing those to the EBC's I now had in hand, I can report no difference at all in backing plate shape, pad material sizing, wear sensor wire or otherwise. Just different advertised compound. Red backing plate for the EBC's, and a break-in material coating on the pad that seems kind of like rubberized fine sandpaper grit material. A week later, I got the corrected W12 pads (again, same as S8 I expect). Well, now I saw a slight difference. Backing plate, general appearance and wire connection all the same again so that was good. But, the W12 pad face was slightly SMALLER. Say what? When I lined them up really carefully, the pad material is about 4/32" smaller from the inside of the rotor toward the outside edge of the rotor. The width side to side is the same. And, even though the W12/S8 outer rotor diameter is somewhat larger, the outside curve of the pad seems unchanged. Pads still seemed interchangeable, though I began to wonder why Audi would have changed this. For reference, either set of pads fits cleanly on the running face of the rotors if you just set them there as a loose part. At first my sense was the 385mm pad didn't get quite so close to the hat on the inside, and maybe they didn't want to have the pad cut the disk away there as much. Yet, the rotor is a boat anchor and it looked very robust in this area. As you will see later below in the pics (Picture 6), it turns out the 4.2 pads run out that 1/8 inch closer to the OUTSIDE of the rotor. It still hits the rotor in full, but reduces substantially that "lip" you often see on worn rotors.
For you data hounds out there, I calculated the swept area on a W12/S8 front rotor with OEM pads for the application as about 173.78 sq. inches per rotor, while I got about 175.25 sq. inches when using the 4.2 pad spec, an increase in swept area of about 1.56% per front rotor. Small, but can be seen. I headed off in the 4.2 pad direction using the EBC Red Stuff.
Rotors: More frustration. Unobtainium in a W12/S8/S6 application from companies like Brembo, DBA, EBC or others. Found a BrakeWorld listing once for either "Brembo's" or "Disc Italia's" and e mailed them. But I wasn't convinced it was for real, especially the Brembo's since Brembo itself had no listing for the D3 at all other than a sport brakes kit based on the same basic set up used in the C5 RS6. Then covert4.2's ad popped up. He sent pics and I realized then they are really OEM Audi rotors that have been drilled and slotted. The rotors have the Audi part number laser engraved on them along the edge (4E0 615 301K) and are marked "Made in England", though separately they allude simply to "Germany." Later when I dismounted my stock original OEM rotors and wire brushed them, I found the identical laser markings and text. Thus, supposed BrakeWorld Brembo's = drilled OEM's. Audi might get the disk blanks from Brembo though. Separately covert4.2 got some Disc Italia rears for his set up, which again seemed to have the Audi OEM part numbers and even packaging. Lest you think this is just a W12/S8 write up, they sell these drilled and slotted rotors for 4.2's too. Pricing nets to a couple hundred dollar premium for a more nicely finished set of OEM front rotors.
Calipers and appearance: When I bought the car and was amazed by the design, the drive, the power right now, the goodies and the general finish, I always thought the one let down was the brake finishing, and more so in front. Just not up to the standard of the car. Somewhat sloppy casting of the caliper, lowly manufacturing obvious numbers ink stamped on. Dumb, undersized looking pad spring retainer that had unsightly surface rust (on a California car no less!). No nice paint details. And rotors that look right off my wife's Sienna, just bigger. Old C5 4.2 with HP2's looked classier honestly, and their pad retainer system with the top quick load set up looked like it meant more serious business. Sure mega size rotors on my car, but with hats in plain sight through the wheels with rust splotches. See Picture 5, and I had already painted pad spring retainer by then. Were I Audi, I would have been rejecting parts from my supplier, but I guess not in cost cutting world. At first, I went to work last fall with some catalyst type brake caliper paint. Got it from Tire Rack. I used silver for the calipers and black for the caliper carrier (bracket) and pad retainer. Didn't touch the rotor hats though. Somewhat time consuming--basically a weekend off and on with brakes disassembled but fluid lines still connected to the car. Several coats to get a deep finish, with some drying time and finish sanding to reduce brush marks. Six months later, I can report the paint holds up w/out any issues--very tough, color fast, no heat related burning or discoloration, etc. Most pictures I post here make the silver look too glossy due to the flash; Picture 5 that I took a bit off angle is a more natural representation of the silver finish--sort of an eggshell.
Pad spring retainer: One of the ho hum things on the current D3 brakes. Looks wimpy. Then I saw the S8 retainer. Really dressed the whole thing up on an S8 (or S6). Gave me an idea. I wasn't wild about the S8 branding on a W12--the sport parallelogram is cool, but S8s and W12's are just different, and I'm not a "pretender" type with badging either. That will take an artist and high temp paints to customize, so for now I left it w/ S8 markings. Might mean the fender W12 logos go. Retainers are pricy by the way; low volume S8/S6 only part.
Total time for job: 80% I would estimate was on the caliper and carrier painting previously. Pads are maybe an hour, assuming a bit of cleaning but not going wild cleaning up wheels, suspension bits, etc. Unremarkable tools. Reinstalling the pad spring retainer is the hardest task, whether original OEM spec or the S8 substitute. Still just takes careful prying with a screwdriver with holding pressure on the clip. Removing the carrier bolts to get the rotors off and later retorquing them takes some effort--torque is well over 100 ft. lbs.--and clearance is awkward if you aren't using a lift. I just used a floor jack.
Performance disclaimers: Okay, its all show, no real go. You could argue it a bit on the drillings, but I won't. These are machine drilled too, rather than factory cast in. Could mean stress cracks later. Slotting does help clean pads and rotor face. Some say slotting or drilling makes audible noise during braking. I hear none at all; note I do have the double paned glass though and D3's are heavily insulated to start. You all probably know these are two pot, two pad rotors with floating pins, not two pot, 4 pad rotors like the old C5 4.2's and D2's, or 4 pots or more for C5 RS6's and the current RS4's. But, relative to the older C5 or D2 4 pad HP2's or the C5 RS6 Brembos, the pad area of these is far bigger, and people came to realize those older brakes really have undersized pads that tend to cook. The D3 overall pad sizing is a plus here. Also, while the disks are real boat anchors, the calipers are aluminum shells. Forgettably called FNR42 AL's (FNR = new floating frame, AL = Aluminum). By contrast, here the old HP2's were the cast iron boat anchors of yore. More trivia: turns out the 385mm rotors have directional vaning internally. BUT, they don't make left and right rotors. Thus on one side of the car the "leading edge" of the directional vanes is at the bottom. On the other side it is effectively at the top. Both old and new rotors are identical that way. The drilling and slotting was done for left and right hand side positioning. That means in practice some of the drill holes penetrated a bit of the internal vaning castings.
More pics:
Close up of new set up:
<img src="http://pictureposter.audiworld.com/26081/rotor_and_caliper_as_installed_small_file.jpg">
Picture 3
Even closer:
<img src="http://pictureposter.audiworld.com/26081/new_brakes_most_close_up_small_file.jpg">
Picture 4
Old set up with wheel off:
<img src="http://pictureposter.audiworld.com/26081/old_brake_set_up_small_file.jpg">
Picture 5
Close up of pad swept area after some initial use:
<img src="http://pictureposter.audiworld.com/26081/new_brake_set_up_rotor_swept_area_small_file.jpg">
Picture 6
New (4.2 size) vs. old (W12 (S8) size) pads placed on rotor w/ outer pad edge flush to outer rotor edge. Note number printed on OEM pad does NOT match the number on the pad box I put in the text above; inside and outside pads apparently have different part subnumbers on them:
<img src="http://pictureposter.audiworld.com/26081/pad_sizing_small_file.jpg">
Picture 7
Rears are still to go, though covert4.2 already posted a very similar set up. Mine will have the Red Stuff pads and a black painted carrier bracket spiff. Rear calipers themselves are better finshed that the fronts.
Closing side fender shot (brake trim and fender logo inconsistency noted):
<img src="http://pictureposter.audiworld.com/26081/fender_side_view_small_file.jpg">
Picture 8
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faisalfaisal (07-09-2023)
03-06-2008, 05:10 AM
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Re: Front brake quasi OEM mod--more show than go fun; feasible on all D3's (rotor sizes vary)
Looks Very professional where did you get the S8 decal, I was thinking of doing a S line decal?
It's a good look.
It's a good look.
03-06-2008, 10:27 AM
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For anyone interested, i've got a set of the 385mm W12 calipers available
from there you need the rotors, and Pad Spring retainer. But for most d3'ers the 385mm is a great upgrade, and one that uses all OEM parts.
Email me if you're interested - prefer to get them out of my garage them have them gather dust...
cheers ~
Email me if you're interested - prefer to get them out of my garage them have them gather dust...
cheers ~
03-07-2008, 01:32 PM
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Re: Front brake quasi OEM mod--more show than go fun; feasible on all D3's (rotor sizes vary)
Nice one very very nice!
A point for you get, ATE pads and discs. It is who makes the calipers for Audi.
My discs were £55 each and full set of front pads were £60 for the set.
So $110 per discs and $120 in your currency. Bargain I think!
A point for you get, ATE pads and discs. It is who makes the calipers for Audi.
My discs were £55 each and full set of front pads were £60 for the set.
So $110 per discs and $120 in your currency. Bargain I think!
07-11-2009, 11:05 AM
#7
They look AWESOME!
Recently I replaced all of my pads and Rotors.This was done on my A6 c6-2005 Quattro,What I did with my Mechanic after some Heavy analysis and research.I bought some G2 paint for the Rotors and got Akebono Pads/Ceramics for the front.The Rotors,are Rotora Crossdrilled and Slotted.In the rear I just have the OEM zimmermans with standard pads.When I get an oppurtunity I will post some of the pictures.-I wish the calipers were more refined.That plate were the S8 decal is on looks great.Like to find one for the A6.
Recently I replaced all of my pads and Rotors.This was done on my A6 c6-2005 Quattro,What I did with my Mechanic after some Heavy analysis and research.I bought some G2 paint for the Rotors and got Akebono Pads/Ceramics for the front.The Rotors,are Rotora Crossdrilled and Slotted.In the rear I just have the OEM zimmermans with standard pads.When I get an oppurtunity I will post some of the pictures.-I wish the calipers were more refined.That plate were the S8 decal is on looks great.Like to find one for the A6.
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10-12-2012, 08:32 AM
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