Exhaust Question

Discussion in 'Modifications And Maintenance' started by goodhart, Oct 30, 2009.

  1. goodhart
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    goodhart Well-Known Member

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    I am currently looking for an aftermarket downpipe for my car, but I have one small issue. I have a 3" spt catback on the car right now and it utilizes a donut gasket. While looking at downpipes, I noticed that most of them are a flat gasket.

    Question #1- Does anybody know of a downpipe that will work with a donut gasket?

    Question #2- I seen this nifty little adapter thing online, but could only find ones that neck down to 2.5" and not straight thru 3". Does anybody make one that doesn't neck down? Picture below is what i am talking about.

    [​IMG]



    I have searched NASIOC and here and could not find much for good info on this subject.



    -Mike
     
    goodhart, Oct 30, 2009
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  2. Shibbs
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    Shibbs The Daywalker

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    If its a donut, it necks to 2.5" anyway.

    Cut and re-weld the SPT to a 3" flat-flange, or sell that one and get a full TBE.
     
    Shibbs, Oct 30, 2009
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  3. ricetiva
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    ricetiva Well-Known Member

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    ricetiva, Oct 30, 2009
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  4. Shibbs
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    Shibbs The Daywalker

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    Yes, and see at the end? It necks down to 2.5"

    Its designed that way to be used with the stock exhaust.
     
    Shibbs, Oct 30, 2009
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  5. retreif
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    retreif Well-Known Member

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    Turbo XS downpipe, at least my stealth back does.
     
    retreif, Oct 30, 2009
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  6. Moleness
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    Moleness I can change the internet

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    So, unless you are makeing mad powers, that 2.5" part won't be a huge deal.

    I am running a flat flange DP with an exhaust made for a donut. Flat gasket+hi-temp silicone=ftw ;) If it were the other way around...not so much.

    But my Cobb DP please. http://mnsubaru.com/forums/showthread.php?t=35434
     
    Moleness, Oct 30, 2009
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  7. Bielke55
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    Bielke55 Well-Known Member

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    SPT can be used on a donut or flat flange gaskets
     
    Bielke55, Oct 30, 2009
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  8. Bielke55
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    Bielke55 Well-Known Member

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    But if you wanna lose the the taper effect... I have a 3" Exhaust steel flange i can sell ya. Then just have someone weld it on for you.
     
    Bielke55, Oct 30, 2009
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  9. goodhart
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    goodhart Well-Known Member

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    OK, I just took some pics of the spt, cause I didn't remember what it looked like and it looks like I could use a flat flange DP???




    [​IMG]
    [​IMG]








    Thanks guys but I want to keep my spt cause its quiet enough for my soon to be born baby son. I really don't plan on spending that much, which is why I'm looking for a cheaper used downpipe, if I can't find one I just plan on going with the Megan Racing unit. I know it probably isn't as great as the other ones but I'm on a bit of a budget with the kid and all.
     
    goodhart, Oct 30, 2009
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  10. AWDimprezaL
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    AWDimprezaL has more posts than you

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    You can use a TXS/invidia/cobb just fine. Furthermore YES, you do NOT need a full 3" untill you are making stupid power, You arent going to lose much if any from a generic stage 2 tune and and SPT cat-back.
     
    AWDimprezaL, Oct 30, 2009
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