View Full Version : Undertrays and Phaeton brake ducts
SYNCRORS2
June 2nd, 2013, 09:04
My RS6 C5 is missing it's undertrays.
Having read up on the extra ducts that they have for cooling turbos, transmission etc... how much of a difference is it going to make not having it there at all? There will be more air moving around but probably not at the right areas.
Also... I am currently breaking a Phaeton W12 and have the front brakes to hand so I have the option of upgrading to the Phaeton ducted backing plates.
I've read conflicting reports as to whether it's better to just remove the original backing plates complete and run without or fit the Phaeton ducted backing plates.
Your thoughts on both please :)
MG
hahnmgh63
June 2nd, 2013, 14:08
I would definitely say using the Phaeton W12 Brake ducts is better as they direct more airflow to the brake disc. I think the undertray is important to keep foreign material out of the bottom area and probably improves high speed drag by improving the flow of air under the car.
lswing
June 2nd, 2013, 18:44
Buy a new undertray for $250. You'll get air forced where it needs to go, and protection from debris. Running with no tray is asking for a serious problem if you get junk up there. And if worried about heat, do the Sportec cooling mod...
1uglymug
June 2nd, 2013, 19:28
See:
http://www.rs6.com/showthread.php/20630-Sportec-lower-air-vent-mod?highlight=Sportec
1uglymug
June 2nd, 2013, 19:30
Does anyone know a where to purchase the Phaeton Brake Ducts for install? I know there are those that have designed their own. And I remember the group buy that went bad. Is there another way to get them?
4everRS
June 2nd, 2013, 19:34
Get them from genuine. Part number searches won't yeild much. Here is a email I got from Bill a while back.
Hi Kyle, 1 2x Phaeton backing plates 3do 615 311c & 3d0 615 312c....are 60.50 each 2 2x Phaeton air ducts 3d0 615 447d & 3d0 615 448d.....Cannot get the D VERSIONS, only the E VERSIONS. As in 3d0 615 447e & 3d0 615 448e. Not sure what the difference is. They are $29.10 each. 3 4x brake bolts 100 650 02...is actually part number N10065002 4 8x securing bolts 908 429 03...is actually part number N90842903 Bill
1uglymug
June 2nd, 2013, 19:59
Awesome! Thanks.
SYNCRORS2
June 2nd, 2013, 21:44
Thanks for the link to the Sportec mod. Worth doing once I have an undertray!
Also, I'll probably carry out the Phaeton brake duct mod as I have the parts.
MG
SYNCRORS2
June 2nd, 2013, 22:54
Next q,
Which is the correct part number for my under tray?
4B3 863 821 C or 4B3 863 821 D
There is quite a difference in price.
4B3 863 821 C has PR-1SA next to it (without power unit underbody guard)
4B3 863 821 D has PR-1SB next to it (engine protection grill)
The comments in () are from the options section of ETOS.
Anyone know what Audi are on about?
Thanks
MG
hahnmgh63
June 2nd, 2013, 23:47
Option decoder say's:
1SB = Additional front underbody guard
1SA = Without additional front underbody guard
My sedan option code lists 1SA so I'm not sure what the front underbody guard would be? Looks like the "C" version for my RS6, the "D" version isn't even stocked in N.America.
SYNCRORS2
June 3rd, 2013, 13:32
Good news, my RS6 came with 4B3863821C which is the cheaper version :)
It's still over £200!!
MG
lswing
June 3rd, 2013, 16:17
Good news, my RS6 came with 4B3863821C which is the cheaper version :)
It's still over £200!!
MG
Came with? Thought you said no tray?
SteveKen
June 3rd, 2013, 17:00
Buy a new undertray for $250.
Please PM me with your source for this pricing.
SYNCRORS2
June 3rd, 2013, 17:06
Please PM me with your source for this pricing.
TPS for this pricing.
My car had an undertray when it left the factory... there were just a few pieces of it left by the time I got the car!
MG
lswing
June 3rd, 2013, 18:04
Dang, just looked at Genuine Audi, $395, yikes!
I just threw $250 out there, actually was $289, two years ago though from same place...
DHall1
June 3rd, 2013, 18:18
Who says printing money has no cause and effect. Same thing happened to all the parts. Remember the brake rotor thread a few weeks back? Rotor prices gone sky high.
Dang, just looked at Genuine Audi, $395, yikes!
I just threw $250 out there, actually was $289, two years ago though from same place...
lswing
June 3rd, 2013, 18:37
I've also been thinking as more of our cars meet their demise, part prices go up, they know we have to buy them...
Other_Erik
June 3rd, 2013, 19:46
Dang, just looked at Genuine Audi, $395, yikes!
I just threw $250 out there, actually was $289, two years ago though from same place...
Feeling like it might be worth it to cut my own from a spare sheet of lexan. Anyone have a template lying around?
No backing plates could damage the rubber tie rod boots due to excessive heat-- or much worse after a hard braking run.