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599 vs HGTE vs GTO Mufflers

Discussion in '612/599' started by George Vosburgh, Mar 4, 2021.

  1. George Vosburgh

    George Vosburgh F1 Rookie

    May 26, 2011
    3,086
    Pittsburgh, PA
    Does anyone really know what the differences are between these three? They kind of look the same. When I hear the HGTE the tone sounds a bit deeper than the 599. I've never heard the GTO live so I cannot say with a 6 to 1 header, but what's the difference in the design of these Mufflers? I know when Dan (DZ-96) put Tubi mufflers on his 599 with straight cat delete pipes he thought it was too loud so he went back to stock mufflers which he thinks is just right. What's the difference in the design that makes such a change??
     
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  3. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
    Full Name:
    Daniel
    George

    I went back from Tubis (which were on the car when I bought it) to stock after installing Fabios 6-1 and cats, because the car was not really silent with closed valves and the valves opened too early which was the main reason.
    With stock mufflers the loudness with the Tubis was OK and the sound was good.

    I can make a scatch from the schematics of the stock and Tubis today.

    Daniel
     
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  4. Justin Hughes

    Justin Hughes Rookie
    Silver Subscribed

    Mar 8, 2020
    44
    Oxfordshire - UK
    Full Name:
    Hughesie
    I've just had the Quicksilver mufflers added and now its bedded in and done 1k miles its a nice rich rumble now !
     
  5. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
    Full Name:
    Daniel
  6. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
    Full Name:
    Daniel
    At the stock, the HGTE and the GTO mufflers, in the outside end pipe, you can see a much smaller tube.
    So I think, the muffler function is the same at all 3, the differences must be inside with more or less baffle plates and/or insulation.

    The tubis function different.

    Daniel
     
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  8. George Vosburgh

    George Vosburgh F1 Rookie

    May 26, 2011
    3,086
    Pittsburgh, PA
    I agree, but I don't think anyone has cut one open to really see what's going on in there!
     
  9. EP328

    EP328 Formula Junior
    Silver Subscribed

    Sep 3, 2008
    582
    Northern California
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    Ed
    Worth too much $$ to cut open. I switched from stock 599 muffler to HGTE. Nicer, deeper tone than stock. The tips, with the black chrome, have a nice, unique look to them as well. Image Unavailable, Please Login
     
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  10. Skidkid

    Skidkid F1 Veteran
    Rossa Subscribed Owner

    Aug 25, 2005
    6,743
    Campbell, CA
    Full Name:
    John Zornes
    Just like mine and they doo look great.
     
  11. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
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    Daniel
    You could go inside with a visual sonde.

    Daniel
     
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  13. George Vosburgh

    George Vosburgh F1 Rookie

    May 26, 2011
    3,086
    Pittsburgh, PA
    True, or maybe a scope. I did not realize exactly why you changed out Tubis but now it makes sense. I just got the GTO grill for the front of my car, I'll put it on in the next few days. The F1 Scud Ing Swiss relay and straight pipes will go on in two weeks.
     
  14. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
    Full Name:
    Daniel
    After installing the 6-1 headers, the Tubis were too loud with closed valves, and after installing stock mufflers, I saw that the valves are closed to higher revs than the valves from the Tubis (up to about 4000 instead up to about 3000).

    The sound with the Tubis is fine, with stock headers, also with 6-1 headers.

    Daniel
     
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  15. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    33,739
    Clarksville, Tennessee
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    Terry H Phillips
    Daniel- Changing mufflers and valves should not affect the opening schedule of the bypass solenoid. Especially since 599 valves are fail open.
     
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  16. DZ-96

    DZ-96 Formula 3

    Mar 7, 2010
    1,168
    South Germany
    Full Name:
    Daniel
    Hi Terry

    I know what you are mean, but it is different with the Tubis and the stock.
    I was very surprised that this happened.

    With the Tubis, it was not possible to get more than 3500 rpm with valves closed, and very difficult to let them closed with more than 3000 rpm.
    A little bit to much throttle and they opened.
    Now it's no problem to get the engine to about 4000 rpm with valves closed, and you can drive in city very normal.
    So I can drive very silent.

    Perhaps the different back pressure has an affect to this ?
    I don't know.

    Perhaps I can sell the Tubis, I don't use them in the future, and I don't change back from the 6-1.

    Daniel
     
  17. Makuono

    Makuono Formula Junior
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    Feb 15, 2014
    884
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    Ricardo
    Probably it is due to a different actuator (diameter or stroke) - requiring less vacuum, hence opening the valve before the stock exhaust?
     
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  18. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    33,739
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    In the case of the 599, vacuum is used to close the valves and springs keep them open. The solenoid actually cuts off vacuum flow to open the valves. I guess it is possible one has stronger springs on the bypass valves and opens more readily, even if both received the same signal from the solenoid and the vacuum was cut off at the same time.

    Cannot argue with empirical data.
     
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  19. Marco599

    Marco599 Rookie

    Apr 5, 2020
    10
    Rotterdam Netherlands
    Full Name:
    marco
    Hello Daniel, i have a quastion if you sell the tubi cat back how much do you want for them ?

    Marco
     

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