Exhaust Question

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

  1. goodhart
    Offline

    goodhart Well-Known Member

    Messages:
    360
    Likes Received:
    0
    Trophy Points:
    201
    Location:
    St. Cloud
    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
    #1
  2. Shibbs
    Offline

    Shibbs The Daywalker

    Messages:
    6,252
    Likes Received:
    74
    Trophy Points:
    283
    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
    #2
  3. ricetiva
    Offline

    ricetiva Well-Known Member

    Messages:
    323
    Likes Received:
    0
    Trophy Points:
    101
    Location:
    west fargo, nd
    ricetiva, Oct 30, 2009
    #3
  4. Shibbs
    Offline

    Shibbs The Daywalker

    Messages:
    6,252
    Likes Received:
    74
    Trophy Points:
    283
    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
    #4
  5. retreif
    Offline

    retreif Well-Known Member

    Messages:
    2,174
    Likes Received:
    623
    Trophy Points:
    298
    Gender:
    Male
    Location:
    Somerset, WI
    Turbo XS downpipe, at least my stealth back does.
     
    retreif, Oct 30, 2009
    #5
  6. Moleness
    Offline

    Moleness I can change the internet

    Messages:
    2,605
    Likes Received:
    182
    Trophy Points:
    248
    Gender:
    Male
    Location:
    At work or in the garage
    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
    #6
  7. Bielke55
    Offline

    Bielke55 Well-Known Member

    Messages:
    5,631
    Likes Received:
    66
    Trophy Points:
    283
    Gender:
    Male
    Location:
    Hopkins
    SPT can be used on a donut or flat flange gaskets
     
    Bielke55, Oct 30, 2009
    #7
  8. Bielke55
    Offline

    Bielke55 Well-Known Member

    Messages:
    5,631
    Likes Received:
    66
    Trophy Points:
    283
    Gender:
    Male
    Location:
    Hopkins
    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
    #8
  9. goodhart
    Offline

    goodhart Well-Known Member

    Messages:
    360
    Likes Received:
    0
    Trophy Points:
    201
    Location:
    St. Cloud
    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
    #9
  10. AWDimprezaL
    Offline

    AWDimprezaL has more posts than you

    Messages:
    16,479
    Likes Received:
    1,821
    Trophy Points:
    573
    Gender:
    Male
    Location:
    Monticello.
    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
    #10