Page 1 of 2 12 LastLast
Results 1 to 18 of 32

Thread: Turbo Upgrade Questions

  1. #1
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85

    Turbo Upgrade Questions

    So here we are again with the question of upgrading turbos. As some of you know, I'm trying to complete my stage 4 MTM tune by doing the turbos and downpipes. I want to upgrade turbos without reconstructing the whole induction and exhaust. So far the only thing I found is the 034 waste gate modification which allows the waste gate to open up at 12 psi instead of 6 which in turn is suppose to allow more boost. There is also the Vast performance billet wheel upgrade which puts in a .59 billet wheel in our turbos and takes the waste gate up to 14 psi. I would like some input on these modifications. Are they safe/reliable? Anybody know anyone who's had them?

  2. #2
    Registered User
    Join Date
    Jul 2008
    Location
    Out there
    Posts
    7,780
    The problem with adding bigger wheels comes into play in the center section. Can the center section take the added cross sectional loads from the larger wheels?

    In addition, the major cap on flow in the RS6 turbo is the size of the turbine housing. You just cant get around the physical a/r ratio in that turbine housing. There in lies the rub. You need larger turbine (hot side) housings in the turbo not just bigger wheels.

    I would max out the current state of tune and make sure everything is working as designed. That means get over to the scope and dyno that bad boy. At the same time complete some data logs and send them to me. I have a ever growing file of data logs as far as the eye can see. Make sure you are putting down what we know a good Stage2 RS6 should be putting down.

  3. #3
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    Quote Originally Posted by DHall1 View Post
    The problem with adding bigger wheels comes into play in the center section. Can the center section take the added cross sectional loads from the larger wheels?

    In addition, the major cap on flow in the RS6 turbo is the size of the turbine housing. You just cant get around the physical a/r ratio in that turbine housing. There in lies the rub. You need larger turbine (hot side) housings in the turbo not just bigger wheels.

    I would max out the current state of tune and make sure everything is working as designed. That means get over to the scope and dyno that bad boy. At the same time complete some data logs and send them to me. I have a ever growing file of data logs as far as the eye can see. Make sure you are putting down what we know a good Stage2 RS6 should be putting down.

    I definitely get what your saying. I'll work on getting some data logs to see if I'm even using max boost with the current turbos. Maybe all I need to do is make my turbos more efficient by ceramic coating them and polishing the turbo exhaust, also ceramic coat and port/polish the exhaust manifolds.

  4. #4
    Registered User
    Join Date
    Jul 2008
    Location
    Out there
    Posts
    7,780
    Vag com data log

    3,31,115...select "turbo" mode before starting to log.

    Find a dead end road safe to drive 95mph and slow down after.

    1. 2 or 3 runs from a standing start thru 3rd gear.
    2. Rolling with tip in 3rd gear at 2800rpm and then hit WOT to redline.

    Send logs to me. ;-)

  5. #5
    Registered User as350's Avatar
    Join Date
    Mar 2010
    Location
    Bend, Oregon
    Posts
    156
    OK, I'm going to show my lack of knowledge with the following question.

    I also own an 01 Audi TT 225 which has a K04 (-23, I think) just like our beasts. I run APR software on my TT along with a few intake and exhaust modifications along with a manual boost controller. My setup allows for peak boost around 22 psi. The K04 will go higher, but at 26 the ECU goes into limp mode and IATs go hot rapidly with higher boost. I know TT owners that are running over 30 psi on a stock K04, but they also have massive intercoolers, w/m injection, different waste gate actuator springs and custom tunes to make it all work.

    So, if the K04 turbos are proven to work at much higher boost, why not swap the RS6 turbos with TT turbos instead of trying to tweak turbine wheels etc.? Is the geometry different and intake/exhaust don't line up?

  6. #6
    Registered User 1sadavant's Avatar
    Join Date
    Feb 2010
    Location
    Pittsburgh, PA
    Posts
    91
    Couple of options:

    1) http://www.eplabs.net/products/vag/r...t-upgrade-kit/

    2) Contact Vast or Blouch Turbo (http://www.blouchturbo.com/) about modifying the wheels. As the aforementioned post hinted, changing the wheels may or may not affect the CHRA. I am sure either of these shops can address this, and I highly doubt it's a problem, plenty of K04-025/K04-026 (OEM RS4) turbos are modified with OEM RS6 wheels and CHRA's as well as OEM Porsche 997 compressor wheels.

    AS350: Your "K04-23" turbo on the TT is not the same as the k04-028 & k04-029 OEM turbo on the RS6. The 23 vs. 28/29 flow characteristics are drastically different, and understandably considering a 4 cylinder vs. 8 cylinder.

    3) Not sure what turbos EPL uses (most likely TIAL 605's or 770's) but considered something of this gt variant. Unfortunately, not many if any here have upgraded their turbos, but it's difficult to find a bolt-on turbo for this platform because of the tight engine bay confines and the exclusivity of the model.

    Look forward to hearing what you find out.

  7. #7
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    Quote Originally Posted by 1sadavant View Post
    Couple of options:

    1) http://www.eplabs.net/products/vag/r...t-upgrade-kit/

    2) Contact Vast or Blouch Turbo (http://www.blouchturbo.com/) about modifying the wheels. As the aforementioned post hinted, changing the wheels may or may not affect the CHRA. I am sure either of these shops can address this, and I highly doubt it's a problem, plenty of K04-025/K04-026 (OEM RS4) turbos are modified with OEM RS6 wheels and CHRA's as well as OEM Porsche 997 compressor wheels.

    AS350: Your "K04-23" turbo on the TT is not the same as the k04-028 & k04-029 OEM turbo on the RS6. The 23 vs. 28/29 flow characteristics are drastically different, and understandably considering a 4 cylinder vs. 8 cylinder.

    3) Not sure what turbos EPL uses (most likely TIAL 605's or 770's) but considered something of this gt variant. Unfortunately, not many if any here have upgraded their turbos, but it's difficult to find a bolt-on turbo for this platform because of the tight engine bay confines and the exclusivity of the model.

    Look forward to hearing what you find out.

    I've been in contact with Vast. They have a customer who just had the wheel mod done on his RS6. They are supposed to let me know the results, I'll let everybody know the results as soon as I get them. They told me to expect 30-40 hp to the crank but have not given me a price for the work.

  8. #8
    Registered User 1sadavant's Avatar
    Join Date
    Feb 2010
    Location
    Pittsburgh, PA
    Posts
    91
    Quote Originally Posted by DALLAS_RS6 View Post
    I've been in contact with Vast. They have a customer who just had the wheel mod done on his RS6. They are supposed to let me know the results, I'll let everybody know the results as soon as I get them. They told me to expect 30-40 hp to the crank but have not given me a price for the work.
    Frankly, I would have imagined more power, but I guess that is pretty typical considering you are only upgrading the wheels. FYI, Vast doesn't have a dyno, so hopefully the owner takes the task of obtaining the results on his own.

    So at roughly a 20% drive train loss and a max gain of 30 FWHP, you are looking at a max of 24 WHP gain over the stock RS6 compressor wheel.

    To put this in perspective, to upgrade the wheels to 997 wheels and new Center Housing Rotating Assembly (CHRA) through Blouch Turbo on a K04-025/026 (RS4 Turbos) it cost $1575 out the door.

    However for new CHRAs (if needed/yours are high mileage) and depending on the wheel you go with, Clipped RS6 vs other, it may be more expensive considering OEM RS6 CHRA's are much harder to source than RS4 CHRAs. Plus, any housing honing that is done.

    So $1575 or more for a gain of 24WHP, may be a hard pill to swallow. For the price, I would look to just upgrade the turbos to something larger...but this is a slippery slope.

    Alternatively, you could possibly work with Vast to upgrade your fueling and a specific tune with an aquamist methanol kit to make your current setup even more efficient and powerful. I assume you have upgraded IC's?
    Last edited by 1sadavant; January 20th, 2011 at 07:40.

  9. #9
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    Quote Originally Posted by 1sadavant View Post
    Frankly, I would have imagined more power, but I guess that is pretty typical considering you are only upgrading the wheels. FYI, Vast doesn't have a dyno, so hopefully the owner takes the task of obtaining the results on his own.

    So at roughly a 20% drive train loss and a max gain of 30 FWHP, you are looking at a max of 24 WHP gain over the stock RS6 compressor wheel.

    To put this in perspective, to upgrade the wheels to 997 wheels and new Center Housing Rotating Assembly (CHRA) through Blouch Turbo on a K04-025/026 (RS4 Turbos) it cost $1575 out the door.

    However for new CHRAs (if needed/yours are high mileage) and depending on the wheel you go with, Clipped RS6 vs other, it may be more expensive considering OEM RS6 CHRA's are much harder to source than RS4 CHRAs. Plus, any housing honing that is done.

    So $1575 or more for a gain of 24WHP, may be a hard pill to swallow. For the price, I would look to just upgrade the turbos to something larger...but this is a slippery slope.

    Alternatively, you could possibly work with Vast to upgrade your fueling and a specific tune with an aquamist methanol kit to make your current setup even more efficient and powerful. I assume you have upgraded IC's?
    I agree, I've done some thread searching and found that the S4 guys are paying around $2000 for this upgrade on RS6 turbos. I don't think it's worth the minimal power gains I would receive. Yes I do have the Wagner IC's, 044 pump and 5 bar reg. I agree with you and Dave. So at this point I am going to just rebuild, ceramic coat, polish what I have(turbos and exhaust manifolds). Next question is porting worth doing?

  10. #10
    Registered User
    Join Date
    Jul 2008
    Location
    Out there
    Posts
    7,780
    That is why you should consider dyno and data logs of what you currently have. IMHO looking at the dyno results from last weekend and 50 data logs from the event...we are quickly approaching terminal limits of the trans. What else is needed from this platform? I would dyno and data log now to see if you're at a similar position and to make sure what you have now is tuned correctly.

    Ask Speedtrapped if his car needs to be faster. It already scares him. Lol

  11. #11
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    We will have some logs soon via dyno thanks to Steve at AutoScope!

  12. #12
    Registered User skribe's Avatar
    Join Date
    Jan 2010
    Location
    Beer City
    Posts
    952
    Lose 20lbs off your gut, dump your spare and jack, get a smaller battery and you'll get the same gains.

    GT28s and a six-speed would be a better route IMHO.

  13. #13
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    Quote Originally Posted by skribe View Post
    Lose 20lbs off your gut, dump your spare and jack, get a smaller battery and you'll get the same gains.

    GT28s and a six-speed would be a better route IMHO.
    Hmmm... Carbon Fiber hood and deck lid.

  14. #14
    Registered User V8weight's Avatar
    Join Date
    Dec 2008
    Location
    St. Paul, MN
    Posts
    2,249
    I'm not sure that a carbon fiber hood would offer much in weight savings over the factory aluminum one.
    Pat - Eisenmann race exhaust, Catless downpipes, KW V3's, H-Sport sways, 034 Control arms, Apikol diff mount, Sterns motor mounts, Forge dv's, Stainless brake lines, Venair hoses, Sportec vent mod, Euro tails, Viper Tuned ecu/tcu, DPE S20's 19x9.5, 275/30/19's

  15. #15
    Registered User JSRS6's Avatar
    Join Date
    Mar 2010
    Location
    Virginia Beach, VA
    Posts
    3,318
    It wouldn't. You MIGHT get 10-15 lbs savings.
    Avus RS 6, RNS-E/BT/RVC, Eurocharged/MTM, SuperSports, PSS9/Hotchkis, SS Lines/EBC Reds, FMU/BMC, Sportec vents, 007's, 9500ci, Black Optics/Headlights/Trim/Rims, CC; coming soon: stage 3 snow meth

  16. #16
    Registered User ttboost's Avatar
    Join Date
    May 2009
    Location
    CT
    Posts
    2,457
    Yup. There are MUCH more cost effective ways to achieve weight savings...
    2013 Audi S8

  17. #17
    Registered User DALLAS_RS6's Avatar
    Join Date
    Apr 2009
    Posts
    85
    Dave, the logs have been sent to you via email. Thanks!

  18. #18
    Registered User
    Join Date
    Dec 2007
    Location
    Pittsburgh, PA area
    Posts
    1,263
    Working with the same outer geometry turbo will never get you the bang for the buck you're after.

    It's been alluded to above, but my intent on RS6 V3.0 if & when this happens is something like a set of TiAl R650s with V-band flanges and some elegant fabrication.

    I can attest first hand that the manual transmission provides much more room for bigger turbos. I've also got a source where I can get the cores for fitment. I'm not sure if removing the bolt on flange and adding the v-band flange on the same plane will work. Luckily I've got an extra set of RS6 manifolds to experiment with.

    So, to recap:

    1. Manual tranmission, which I'd recommned whether upgrading or not, just from a pure reliability standpoint.

    2. An aftermarket turbo with better performance (also most likely cheaper) than a stock set of Borg Warners.
    2012 Q7 TDI S-Line - 2010 GTI - 2007 A3 3.2 S-Line - 2003 RS6
    2001 Honda S2000 - 1977 Honda CBR 750-F2 - 1965 GMC 1500 WideSide

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •