Close

Page 1 of 2 12 LastLast
Results 1 to 25 of 32
  1. #1
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411


    Yes Reputation No

    What's the big deal about twin scroll turbochargers?

    Many readers are familiar with twin scroll turbocharger systems but it never hurts to in basic terms explain turbocharger technology which can seem like witchcraft to the casual car fans. In the most basic of terms, a twin scroll turbocharger is like having two turbos in one.

    Click here to enlarge

    How is that possible you say? Well, just think of your classic V6 or V8. There are two exhaust banks. Traditionally, an efficient turbocharger setup would mean two turbos hanging off the manifolds at the bottom of the car. Each is fed by that set of cylinder banks which it is connected to. It looks like this:

    Click here to enlarge

    Such a setup can make a ton of power, no doubt about it. A good twin set of modern single scroll turbochargers on a V8 or V6 can produce quadruple digit horsepower. However, look at all that piping. Look at the distance the exhaust gases have to travel. Can a single twin scroll turbo do the job of these twins more efficiently?

    Absolutely. Imagine if the exhaust gases traveled to the turbocharger right from the cylinder head. That poses a packaging problem but one that a twin scroll turbo helps alleviate. The new B9 Audi S4/S5 3.0 TFSI turbo motor is a great example of this:

    Click here to enlarge

    Audi placed a twin scroll turbo in the V at the top of the motor and with a very trick manifold feeds a single turbo with both banks of exhaust pulses. It is like having two in one yet also with the benefit of less piping, less travel distance, and quite simply greater efficiency.

    BMW started the trend with a pair of twin scroll turbochargers mounted in the valley of their S63 V8. It is the same principle except they are feeding two turbochargers with a cross engine manifold:

    Click here to enlarge

    Click here to enlarge

    Click here to enlarge Originally Posted by BimmerBoost
    The S63 is based on the N63 but there are some very significant differences between the two motors. The main difference being that the S63 uses a pulse tuned, cross engine exhaust manifold. That sounds cool, but what does it mean? It means that each turbo gets its exhaust flow from 4 exhaust pulses but also from opposite cylinder banks. This exhaust gas is fed into twin-scroll turbos which means there are two passages for the exhaust gases in the turbos. The N63 on the other hand uses single scroll turbos which means one passage for the exhaust gases. It is this pulse tuned exhaust manifold as well as the twin-scroll turbos that is major difference in the architecture of the S63 vs. the N63.

    BMW has two V8 twin turbo motors, the N63 and the S63, but the S63 outpaces the N63 considerably. Why? Because of the twin scroll cross manifold design. The N63 can essentially be turned into an S63 by changing the manifold and turbos and that is basically what an S63 is.

    Imagine turbochargers being fed by pulses from both banks instead of just one bank. That is exactly what a twin scroll setup does with the turbocharger taking in exhaust gases from both banks.

    This pays dividends in many areas. Spool is said to be increased which leads to low end torque gains as well as an improvement in throttle response. The turbos in theory will make more power through the rev range as they are continuously fed with exhaust pulses through the curve
    . One should also see a decrease in intake charge dilution during valve overlap along with lower exhaust gas temperatures. You also have reduced pumping losses and better fuel consumption.

    What are the disadvantages? There really aren't any other than more manufacturing and tuning complexity. In theory a good sized single twin scroll turbo will cost you less than a pair of high end traditional turbos.

    The main thing to get right is the firing order feeding the twin scroll turbo. For example a four-cylinder motor usually fires 1-3-4-2. You would want one exhaust passage to get gases from the number 1 and 4 cylinders and the other from the 3 and 2 cylinders.

    This may all sound too good to be true but the principle has been tested and a twin scroll setup is simply more efficient:

    Click here to enlarge

    More power through the curve? Yep:

    Click here to enlarge

    You also get the benefit of greater boost at lower engine speeds which is that low end torque and response benefit discussed earlier.

    You are going to see more and more twin scroll turbocharger applications in production cars. Expect variable geometry twin scroll turbochargers as well which means the turbocharger has vanes that can adjust. This way the turbocharger can adjust itself to maintain the speed of gas flow based on how much exhaust gas it is being fed.

    Turbo lag will never be eliminated but with twin scroll and variable vane turbo technology manufacturers are getting so close it may no longer matter. The modern turbo era is providing excellent response, efficiency, and power with fuel economy nobody would have thought possible not too long ago.

    Much respect to twin scroll technology!

  2. #2
    Join Date
    Aug 2012
    Location
    FLORIDA BITCHES
    Posts
    247
    Rep Points
    805.2
    Mentioned
    6 Post(s)
    Rep Power
    9


    Yes Reputation No
    Beautiful description

  3. #3
    Join Date
    Jul 2010
    Location
    Encino,CA
    Posts
    9,152
    Rep Points
    7,146.1
    Mentioned
    231 Post(s)
    Rep Power
    72


    Yes Reputation No
    I still wonder to this day why people do single scroll when twin scroll is that much better.
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, S55s, N63s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.

  4. #4
    Join Date
    Sep 2012
    Posts
    2,193
    Rep Points
    3,261.0
    Mentioned
    30 Post(s)
    Rep Power
    33


    Yes Reputation No
    Can't wait to see what aftermarket does with new S4/S5 hot-v turbo V6.

  5. #5
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by BlackJetE90OC Click here to enlarge
    Can't wait to see what aftermarket does with new S4/S5 hot-v turbo V6.
    Me either. Very impressed with that engine design.

    It's the new 335 except better in every way.

  6. #6
    Join Date
    Dec 2015
    Location
    New Jersey
    Posts
    113
    Rep Points
    178.0
    Mentioned
    52 Post(s)
    Rep Power
    2


    Yes Reputation No
    So much research and development behind this twin scroll setup to actually make it work right but if you ask me that positioning of the turbo-turbos in the valley is the key for such improvement in efficiency and performance!

  7. #7
    Join Date
    Sep 2012
    Posts
    2,193
    Rep Points
    3,261.0
    Mentioned
    30 Post(s)
    Rep Power
    33


    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Me either. Very impressed with that engine design.

    It's the new 335 except better in every way.
    Some engine pics from the press event.

    Click here to enlarge

    Click here to enlarge

    Click here to enlarge

    Click here to enlarge

  8. #8
    Join Date
    Nov 2015
    Location
    miami
    Posts
    425
    Rep Points
    876.2
    Mentioned
    8 Post(s)
    Rep Power
    9


    Yes Reputation No
    interested to see if the rs variants get 2 twin scrolls or the new electric turbo audi is putting on there SQ7... heard talk of both and would love to see an electric turbo'd rs car

  9. #9
    Join Date
    Oct 2014
    Posts
    2,196
    Rep Points
    30.0
    Mentioned
    27 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Me either. Very impressed with that engine design.

    It's the new 335 except better in every way.
    Nothing Audi makes is better than BMW, period. I have owned and do own both and I will never own another VAG built piece of $#@! for as long as I live. The quality is horrendous to say the least. I battled Audi NA for months to have a motor replaced when it let go a day after a cam replacement by an Audi dealer and the Audi rep told me that they don't built their cars to out live lease terms anymore. That alone says everything. Viva la BMW!!!

  10. #10
    Join Date
    Apr 2014
    Location
    ATL
    Posts
    2,414
    Rep Points
    2,688.2
    Mentioned
    14 Post(s)
    Rep Power
    27


    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Nothing Audi makes is better than BMW, period. I have owned and do own both and I will never own another VAG built piece of $#@! for as long as I live. The quality is horrendous to say the least. I battled Audi NA for months to have a motor replaced when it let go a day after a cam replacement by an Audi dealer and the Audi rep told me that they don't built their cars to out live lease terms anymore. That alone says everything. Viva la BMW!!!
    You are right about the Audi part but BMW isn't much better reliability wise.
    This just might be my next company car Click here to enlarge

    Click here to enlarge
    Cadillac CTS-V - 6MT - Lingenfelter upper pulley, Airaid CF Intake, Magnaflow exhaust, fluidyne H/X

  11. #11
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by kbaldi29 Click here to enlarge
    So much research and development behind this twin scroll setup to actually make it work right but if you ask me that positioning of the turbo-turbos in the valley is the key for such improvement in efficiency and performance!
    Absolutely. That turbo placement and manifold would be almost wasted on a single scroll setup.

  12. #12
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Nothing Audi makes is better than BMW, period.
    Really?

    Because I count the R8, TT RS, RS6, RS7, S8, S8 Plus, S4, and S5.

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    I have owned and do own both and I will never own another VAG built piece of $#@! for as long as I live.
    How I feel about BMW these days.

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    That alone says everything.
    Does it? http://www.bimmerboost.com/content.p...ct-of-all-time

  13. #13
    Join Date
    Oct 2014
    Posts
    2,196
    Rep Points
    30.0
    Mentioned
    27 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Really?

    Because I count the R8, TT RS, RS6, RS7, S8, S8 Plus, S4, and S5.



    How I feel about BMW these days.



    Does it? http://www.bimmerboost.com/content.p...ct-of-all-time
    Those Audi models will not outlast BMW models in longevity and reliability. Which is what I am referring to. I could care less if a car performs "better" if everything is always falling apart on it.

    Unless your M3 isn't your only BMW, then I don't even know how you could have a real personal opinion on BMW quality. Any issue you've had with your M has nothing to do with BMW and everything to do with Gintani.

    Yes, the S55 crank hub is astonishing, but it is something that could easily be fixed with a recall to insert a proper key way and key, not some BS sheer pin like the aftermarket has added.

    PS I will forever maintain, unless Audi gets their $#@! together, which they won't, that Audis are overpriced hunks of $#@!.

  14. #14
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Those Audi models will not outlast BMW models in longevity and reliability.
    Based on what?

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Unless your M3 isn't your only BMW, then I don't even know how you could have a real personal opinion on BMW quality. Any issue you've had with your M has nothing to do with BMW and everything to do with Gintani.
    You are absolutely right about Gintani.

    What you are wrong about is my BMW experience. My very first car was an E46 330i and my E92 M3 is as a matter of fact my second M3. I've had four BMW's total. They all had issues.

    I have almost two decades of BMW experience now... not to mention having read more about them than just about anyone I would think.

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Yes, the S55 crank hub is astonishing, but it is something that could easily be fixed with a recall to insert a proper key way and key, not some BS sheer pin like the aftermarket has added.
    You didn't read the article. It doesn't just touch on the S55 crank hub but M3 engines for going on three generations. That is quite a problem, isn't it?

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    PS I will forever maintain, unless Audi gets their $#@! together, which they won't, that Audis are overpriced hunks of $#@!.
    BMW is not thing special either.

  15. #15
    Join Date
    Oct 2014
    Posts
    2,196
    Rep Points
    30.0
    Mentioned
    27 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    BMW is not thing special either.
    I never claimed they were. I simply made the statement that Audi is $#@!, and BMW is better, then provided facts to back my opinion. When you have a person who represents a company say that the company they represent doesn't design their products to last, that speaks volumes. /debate.

  16. #16
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    I simply made the statement that Audi is $#@!, and BMW is better, then provided facts to back my opinion
    I didn't see any facts. What facts?

    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    When you have a person who represents a company say that the company they represent doesn't design their products to last, that speaks volumes. /debate.
    What do you think BMW does? The exact same thing. Disposable cars. Get into a new lease as quickly as possible, that's their strategy.

    Both are overrated but Audi has better junk.

  17. #17
    Join Date
    Sep 2012
    Posts
    2,193
    Rep Points
    3,261.0
    Mentioned
    30 Post(s)
    Rep Power
    33


    Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    Audi rep told me that they don't built their cars to out live lease terms anymore. That alone says everything. Viva la BMW!!!
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Really?
    How I feel about BMW these days.
    How I feel about BMW too. I will never own another modern BMW past the 4yr 50k warranty. They are complete POS money pits. Lost count how many times my 335i and M3 were in the shop.
    Last edited by BlackJetE90OC; 07-03-2016 at 06:43 PM.

  18. #18
    Join Date
    Sep 2012
    Posts
    2,193
    Rep Points
    3,261.0
    Mentioned
    30 Post(s)
    Rep Power
    33


    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by The Convert Click here to enlarge
    I never claimed they were. I simply made the statement that Audi is $#@!, and BMW is better, then provided facts to back my opinion. When you have a person who represents a company say that the company they represent doesn't design their products to last, that speaks volumes. /debate.
    Your fact is what some random guy from Audi said.

    Facts would be referencing the last reliability studies done by JD Power and Consumer Reports. Which ironically both have Audi ranked higher than BMW.

  19. #19
    Join Date
    Apr 2014
    Location
    ATL
    Posts
    2,414
    Rep Points
    2,688.2
    Mentioned
    14 Post(s)
    Rep Power
    27


    Yes Reputation No
    Click here to enlarge Originally Posted by BlackJetE90OC Click here to enlarge
    How I feel about BMW too. I will never own another modern BMW past the 4yr 50k warranty. They are complete POS money pits. Lost count how many times my 335i and M3 were in the shop.
    Totally agree. Sold my E90 couple weeks ago and will only go older now unless I decide to lease or just buy CPO and dump it again as soon as the warranty is up.
    Meanwhile my wife's 2005 X3 has been the picture of reliability. (knock on wood lol)
    Cadillac CTS-V - 6MT - Lingenfelter upper pulley, Airaid CF Intake, Magnaflow exhaust, fluidyne H/X

  20. #20
    Join Date
    Jan 2015
    Posts
    926
    Rep Points
    1,139.4
    Mentioned
    30 Post(s)
    Rep Power
    12


    Yes Reputation No
    I wouldnt say an engine is better because of its turbo positioning. The audi V6 is just different, not better.

  21. #21
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    137,710
    Rep Points
    41,019.0
    Mentioned
    2418 Post(s)
    Rep Power
    411



    Yes Reputation No
    Click here to enlarge Originally Posted by 93siro Click here to enlarge
    I wouldnt say an engine is better because of its turbo positioning. The audi V6 is just different, not better.
    It's not just the turbo positioning... a bit more involved than that.

    Yes, it's better.

  22. #22
    Join Date
    Mar 2012
    Posts
    383
    Rep Points
    391.9
    Mentioned
    11 Post(s)
    Rep Power
    4


    Yes Reputation No
    It would be very very interesting if a simple stage 1 tune will run mid-high 11's (crossing my fingers) on 93 octane.

  23. #23
    Join Date
    Sep 2011
    Posts
    77
    Rep Points
    36.5
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    cool article

  24. #24
    Join Date
    Jan 2015
    Posts
    926
    Rep Points
    1,139.4
    Mentioned
    30 Post(s)
    Rep Power
    12


    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    It's not just the turbo positioning... a bit more involved than that.

    Yes, it's better.
    Yes like a complex balancer system so it will not shake itself to death. The only 90 degree V6 good in making power was the Buick V6 and that had mostly to do with the rigid block, displacement and of course the aftermaeket support that no Audi V6 will have.

  25. #25
    Join Date
    Apr 2014
    Location
    ATL
    Posts
    2,414
    Rep Points
    2,688.2
    Mentioned
    14 Post(s)
    Rep Power
    27


    Yes Reputation No
    Click here to enlarge Originally Posted by 93siro Click here to enlarge
    Yes like a complex balancer system so it will not shake itself to death. The only 90 degree V6 good in making power was the Buick V6 and that had mostly to do with the rigid block, displacement and of course the aftermaeket support that no Audi V6 will have.
    I agree that 90 degree V6's are inherently compromised because they want to share a block with a V8. The firing order and balance is terrible. Yeah they can make it work and the Audi engine will probably be nice but I still don't like the idea of it.
    Cadillac CTS-V - 6MT - Lingenfelter upper pulley, Airaid CF Intake, Magnaflow exhaust, fluidyne H/X

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

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