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VZ SV6 sedan exhaust

Discussion in 'VZ Holden Commodore (2004 - 2006)' started by SwitchRunner, May 21, 2018.

  1. SwitchRunner

    SwitchRunner New Member

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    I’m after a cat back system for my SV6. I have looked a lot of threads on this topic but nothing with enough info. The stock system is very quiet and I can only ever hear the engine. I want something that is quiet down low and on start up so it’s possiable to drive early morning and late night so I don’t wake anyone up. But barkey up high with some crackle on back off when I give it some. I’ve looked at different brands like redback, manta, xforce, rhino, ES, DI FILIPPO. Can I get some advice please if you know anything about different SV6 VZ exhaust systems or your experience or if this is even possiable to achieve.
     
  2. Mattde

    Mattde Member

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    Hey mate,
    I can assure you that at the end of the day you will have to decide for yourself as a lot to do with exhaust comes down to personal preference.
    That being said, for an alloytec I recommend (from experience) a Single Manta 2.5" catback, maybe even a rear resonator delete if you want a bit more volume.
    A really good option for what you're after: discreet when you need to be, 0 drone, and a great note when you give it some.
    website: http://www.mantapro.com.au
    They have a live chat to help you out as well.
     
  3. SwitchRunner

    SwitchRunner New Member

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    Cheers dude I’ll think I have to give that a go a lot of people have been saying that set up. Ill tweak it from there.
     
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  4. Shelbyr

    Shelbyr New Member

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    Hey bro I'm looking for the exact same thing. But so many options available and no idea what one to get. Did you end up fitting an exhaust? And what did you put on?
     
  5. SwitchRunner

    SwitchRunner New Member

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    Hello Shelbyr, I still have not put an exhaust system on my car yet because of loss of license. What i decided on after much more research is go into a exhaust shop and get a custom "cat back" system. You can explain to them what you want and they can guide you into the right direction. You may not even need a cat back system if the pipes are fine then all you need to do is change the mufflers. Cat back system is more about changing the over all sound rather then gaining performance but still does help and more so if you go for extractors/cats. Yes just buying a premade cat back system maybe a little bit cheaper but you will not end up with the sound range you will be happy with. From what ive seen they will be either be to quiet or to loud and then your stuck with that cat back system that you might not like then need to sell it. But if you feel you need to do it your self and save some money i would go a twin 2.25inch xforce mild steel it meant is for the v6 the 2.5inch variant is meant for the v8. Unless you know different exhaust systems well and know what they sound like in real life, some what decent video of the system, happy with what you think it sounds like or want to save some money then go for the pre built twin 2.25 system does sound nicest from all the cat back systems i have heard. But if you want it done right then i would go with a custom system you can talk to these people until they need to close there doors for the day then your system will sound how you want it to and can be happy with it 100%.
     
  6. Shelbyr

    Shelbyr New Member

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    Thank you for your reply.
    Yes getting a custom exhaust done was what I was going to do in the first place. But everyone told me to buy a bolt on one as its cheaper and they were saying why would you want to spend so much. I had a look at them but if it doesn't sound right it will be a waste of time. I have got xforce headers which I will put on and if I do go with a custom exhaust they will make it fit to those, will also do my cold air intake. Thanks for helping me out there so many posts about different things but I'd rather spend money and get something that sounds and gains how I like it.
     
  7. Not_An_Abba_Fan

    Not_An_Abba_Fan Exhaust Guru

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    Manta used to do a twin 2 1/4" into single 3" that sounded really nice, but there wan't enough product being sold to warrant continuing. This would be the ideal custom system, 2 mufflers up front where the factory ones are, then into a collector to a single 3" large rear resonator.
     
  8. SwitchRunner

    SwitchRunner New Member

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    Do not worry about the fitment they will have all the pipes/flanges/hangers/muffler/cats/tips you can poke a stick at and will fit any system no problem. They are right about the prebuilt being cheaper but with custom system your only adding labor, the mark up on the parts will pretty much be the same as the prebuilt system. Also you may not even need to buy top end brands for the custom system for the sound you want, like if you would have done if you bought a prebuild system to get the best out box set up to be "safe" with the quality of sound. You can now focus on what mufflers you want and the sound your looking for. You are then able to fine tune the sound from that because there are so many mufflers to choose from. The pipes are about flow and do not effect the sound nearly as much as mufflers do. So get pipes that give max flow and enough back pressure for the engine to run perfect. From what i have found out twin systems are deeper then single systems for a v6 and 2.25inch in the twin config seems to be the right back pressure for the stock N/A Alloytec to maximize on performance. For another 100 to 200 extra you get a guarantee on the work that they have done including the sound and quality also years of experience so when your explaining to them what you want they can give you a short list of what they think is best suited to you and you just say a little louder or a little quieter etc until your happy with your set up. So at the end of the day do you need to save money or do you need to be happy with your car?
     
  9. harrop.senator

    harrop.senator Well-Known Member

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    Please tell me more about the correct back pressure?
     
  10. SwitchRunner

    SwitchRunner New Member

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    Well what did you need to know?
     
  11. harrop.senator

    harrop.senator Well-Known Member

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    How does one achieve max flow while retaining back pressure? Sounds like an oxymoronic situation.
     
  12. SwitchRunner

    SwitchRunner New Member

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    With the correct exhaust system. Both of those things occur at the same time.
     
  13. harrop.senator

    harrop.senator Well-Known Member

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    It's an old wives tale back pressure used to be used as a reasoning for increase in velocity I think I've even got a book from the 70's or 80's that tries to use it as a theory of performance and may old timers will use in term of expression. I think I've even used it before someone told me to read the more modern findings on exhaust science.

    http://www.gomog.com/allmorgan/exhaustbackpressure.html

    Had a quick glance over this article seems about right.
     
  14. SwitchRunner

    SwitchRunner New Member

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    Okay i read through most of the article. Its pretty much what i said about my first comment that you asked your question about. I said "So get pipes that give max flow and enough back pressure for the engine to run perfect". The article says "Exhaust designer knows that you must balance flow capacity with velocity". I was not using back pressure measurement as a sign of increased velocity of the exhaust gases. I was just saying that you need to balance with having flow and back pressure/scavenging thats right for the engine.

     
  15. Not_An_Abba_Fan

    Not_An_Abba_Fan Exhaust Guru

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    Back pressure is bad, you don't want it at all. Anyone that says you do does not know how exhaust velocity works. Some people get back pressure confused with reversion waves, you NEED those, but not back pressure.
     
  16. SwitchRunner

    SwitchRunner New Member

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    Yes back pressure is bad but you still have to have some for scavenging to work properly. You want to maximum amount of velocity and have minimal amount of back pressure also reversion waves aid in the scavenging process. You are always going to run into back pressure because you are pumping the exhaust gas into at least 1ish atmosphere of pressure. A small pipe will give you more back pressure also more velocity but a big pipe will give you less back pressure and less velocity. Balancing your back pressure is a must.
     

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