2008 RS4 build thread

[EricZ]

Hi everyone! I joined the forum last year just prior to buying my first Audi, a completely stock 2008 RS4 with 65k miles in beautiful shape. It was a dream come true and I didn't waste any time making it "mine".

[EricZ]

The first changes I made included a 034 Rear sway bar with adjustable end links, KW V3 coilovers, 034 density front control arms, ECS short throw shifter, Goodridge brake lines, and an ECS H-pipe to add a bit of sound while I planned some much bigger changes.

[EricZ]

Now the fun begins! Since I am the Aftermarket Program Manager for BorgWarner Turbo Systems, I have access to some neat hardware and I took advantage of an opportunity to do some testing. With a 72mm S400SX-E and two 48V pre-production eBoosters, this build is all about a flat torque curve and not much more. My target is ~500 ft-lbs from as early in the rpm range as possible (~1800 rpm target) thru 8250 rpm. The early torque development will be knock limited, so I'll ramp the eBoosters in as quickly as good combustion will allow.

[EricZ]

The work begins with reshaping sheet metal in the trunk area. The reworked area will make room for the S400 on the left and the twin eBoosters on the right. The exhaust plan is a quick merge from the stock headers to a single 2.5" SS exhaust on the left of the tunnel. This will transition to a brief 2.5" oval section before a 90 deg bend into the turbine housing. The turbine outlet will face forward and split left to a valved 3" dia outlet and right to a 3" muffled outlet. The charge plumbing will head back up front on the right of the tunnel.

Trunk area work to be completed in future post...

[DOCEVG]

Sub'd to watch this ambitious build.
Nice dag and bike, too.

[EricZ]

To document the before and after, I put the car on a local Dynojet to get a baseline. It's been about 15k miles since the last carbon clean so I'd consider this pretty solid results for a stock daily driver. She has 80k miles on her now.

[EricZ]

The eBooster control plan is to use a RaceCapture Track unit to read all ECU data thru the CAN bus, then command the eBoosters via the 2nd RaceCapture CAN bus based on the control logic I create using Lua scripting. To monitor things and access the RaceCapture data, I installed a Xtrons Android 8.0 head unit. This decision went against my preference for OE fit and finish, but it fit well and required only a little work to make it perform great. I ultimately decided to not use the Xtrons RCA outputs to send sound to the factory amplifiers due to the noise, and instead I added some PAC line out converters with integrated ground loop isolators to keep the signal clean. This worked great and things really sound good!

[EricZ]

Here is a cardboard mock up of the new shape for the trunk area. I'm thinking the top area will have a sheetmetal perimeter and a machined aluminum cover that bolts down to the perimeter. This will allow easy access to the top of the turbo and eBoosters while keeping the trunk area sealed off and a clean setup. The stock trunk carpet will remain to keep the OE look and function.

[PigDiesel54]

Wow can't wait to see the outcome. Some of the photos you posted have broken links.

Sent from my SM-N950U using Audizine mobile app

[EricZ]

It seems like some of the embedded pics dont show on my phone but show just fine thru my PC. I use the same process to embed all photos: Copied image link from Google Photos, shortened link using goo.gl, then used the "Insert Image" link in the forum to [IMG] it....hmmm

[Pyromatic177]

I see no pics, and I certainly want to lol

[PigDiesel54]

I've never had a problem using imgur on AZ

Sent from my SM-N950U using Audizine mobile app

[ginch]

Cant see pics and really want to!

[q_dubz]

Party time Eric. I'll come visit to help 😁

[Nollywood]

I can’t see any photos either...

...and I too really want to.

[jakeoboy67]

I saw the pictures when I first opened the thread, and now they're not working :(

[q_dubz]

Eric,

You can just use the attachments feature on this forum. When you go into edit or reply to a post you can go advanced, click the paperclip symbol or the button below the body text box and click manage attachments. Then upload...

[JorisRS6]

Cant see pics either. Only the video


Sent from my iPhone using Audizine

[EricZ]

Pics should be fixed now...I hope Flikr works better than Google Photos

[eurojunkjon]

I can see them now.

Can’t wait to see this thing finished

[Mal]

This is an awesome build! A stock RS4 captures my attention, a boosted RS4 even more so.

[VinnysS4]

Subbed!!!!

Sent from my SM-N920V using Tapatalk

[b6bydesign04]

Oh my, this should be great. I'd love to see this car in person once it's finished too, we really need to setup a fall mountain run in Asheville considering how many RS4's we have in NC now.

[germanstyle]

Wow, looking forward to seeing the build progress

[Squrl]

Can't wait to see this!

[my_RS4]

Sent from my iPhone using Audizine

[Matt Devo]

I ultimately decided to not use the Xtrons RCA outputs to send sound to the factory amplifiers due to the noise, and instead I added some PAC line out converters with integrated ground loop isolators to keep the signal clean. This worked great and things really sound good!

why use a line-level converter with ground-loop isolator rather than an isolator on the RCAs themselves? Was there a different in sound quality going that route? I tested an XTRONS unit briefly around a year ago, but there was so much noise (GL and otherwise) that it didn't seem like a GLO would be sufficient to resolve the issue (esp when headlights turned on)

[EricZ]

why use a line-level converter with ground-loop isolator rather than an isolator on the RCAs themselves? Was there a different in sound quality going that route? I tested an XTRONS unit briefly around a year ago, but there was so much noise (GL and otherwise) that it didn't seem like a GLO would be sufficient to resolve the issue (esp when headlights turned on)

I tried some PAC GLIs on the RCA outs but they also cut out some of the low frequencies too, so it lost some bass. Also, the overall sound quality from the RCAs was not that great. I did go thru the logical steps and the line level converters was a last resort, but ended up being what I should have done from the beginning. It really sounds awesome now!

[Kambesama]

Does the head unit work with the navigation in the cluster as well or has that been disabled due to the aftermarket unit?

[Matt Devo]

I tried some PAC GLIs on the RCA outs but they also cut out some of the low frequencies too, so it lost some bass. Also, the overall sound quality from the RCAs was not that great. I did go thru the logical steps and the line level converters was a last resort, but ended up being what I should have done from the beginning. It really sounds awesome now!

appreciate the input, thanks!

Does the head unit work with the navigation in the cluster as well or has that been disabled due to the aftermarket unit?

I'm not aware of any aftermarket units which send navigation directions to the cluster. It's not a technical limitation, since they send song info etc, it's just they haven't invested in the software to translate 3rd party map software directions into something usable on the cluster (which is non-trivial)

[bendilzerian]

Wow. Subbed.

[Lesterine2004]

sub-freaking-scribed!

[EricZ]

Does the head unit work with the navigation in the cluster as well or has that been disabled due to the aftermarket unit?

No, the nav in the cluster is disabled with the Xtrons unit. It does show radio, mp3, and cd info, but even that is somewhat limited. This is fine for me since I will ultimately use the cluster display for other information all together, but this is low on the priority list for the build.

[EricZ]

5.5" 90 deg inlet arrived and it will fit, but I may swap to our "compact" compressor cover which has a smaller 5" inlet. Also, 3" vacuum activated exhaust valve arrived. This will control the left exhaust outlet with the "S" button, much like the factory mufflers are setup (more noise with "S" depressed).

[melomandn]

Excited to see how this plays out. Nice buell as well

[EricZ]

Excited to see how this plays out. Nice buell as well

Thanks! That XB12R was a bike I built for someone else, but very similar to the one I just sold. I am now on a KTM Super Duke 1290 R and love it! Here is my old turbocharged XB and build site:

www.streetfighterperformance.com

[itsmatt33]

this thread escalated quickly

[Jnaut]

FF

[turbobrian]

🏭🎉🎉

[ENV²]

Yep, Ill be watching.