Flex uppipe vs Straight Uppipe

Discussion in 'Modifications & DIY how-to' started by Sparta, Jun 3, 2007.

  1. Sparta

    Sparta Active Member

    What is the difference? What are the Advantages of having a flex over straight or vice versa? And do brands really have a difference?
     
  2. WJM

    WJM Banned

    Get one with a flex in it. I HIGHLY recommend the HELIX UP, or a stock STi UP.
     
  3. Demo24

    Demo24 Member

    I'm thinking about getting a sti one.

    However I'm curious what the car would do without an egt bung?
     
  4. WJM

    WJM Banned

    nothing. install the resistor.
     
  5. Sparta

    Sparta Active Member

    A flex? Really? i just ordered an HKS straighty. Is there a big difference?
     
  6. clemsonscooby

    clemsonscooby Active Member

    I have the HKS non-flex for over 40k miles with no problems. I don't believe there is a difference in performance. I don't ever here stories of them breaking on these boards. The stock pipe is not a flex on the Sti and WRX.
     
  7. Sparta

    Sparta Active Member

    sounds good. Thanks!
     
  8. goixiz

    goixiz Active Member

    the stock wrx and sti is flex
     
  9. clemsonscooby

    clemsonscooby Active Member

    What? When I removed my uppipe from my 03 WRX there was no flex what so ever. Even if it was internal, i.e. behind the heatshielding, the heat shielding is one piece and wouldn't allow flex anyways.
     
    Last edited: Jun 3, 2007
  10. moose

    moose Infina Mooooooose!

    They're flex.

    I had a solid Perrin on without any issues.
     
  11. WJM

    WJM Banned

    the stock units have a small flex in them like the stock header crossover pipe does.

    I just dont recommend solids since they break when you hit stuff...when you are going offroad...like Colin McRae.
     
  12. Sparta

    Sparta Active Member

    lol, i dont plan on going offroad anytime soon. but thanks for the advisory
     
  13. Deke

    Deke Active Member


    ooo, you're missing out :)
     
  14. siegelracing

    siegelracing Registered Vendor<br><b><font color="#666666">bion

    Stock is flex. All the good ones are flex. If Subaru thought you could do it without a flex, they would have left the flex out. For every 1 person that doesn't have a problem with a solid, there are 8 or 9 that have them break, crack, or leak.

    We have near 100% success with flex UP's and probably 10-20% success with solid UP's...

    SS
     
  15. clemsonscooby

    clemsonscooby Active Member

  16. WJM

    WJM Banned

    looks like I welded that up on a windy day outside....at night time.
     
  17. pEd

    pEd This ain't no Piccadilly!

    :rofl: Looks like my welding work.
     
  18. Cool_____

    Cool_____ Banned

    Chicken shit welding FTW!
     
  19. KingofSiam

    KingofSiam Member

    Hmmm seems like a pretty strong consensus in this thread for flex uppipes.

    In a closely related issue, it seems that all coated (or otherwise heat-protective) UP's are solid.
    You guys think that stainless steel is good enough or heat wrapping/coating a good idea?
     
  20. WJM

    WJM Banned

    w/e....solid, flex, both, doesnt matter.

    all of them break eventually.

    I'm going to install a solid in mine.
     
  21. MrCoffeeATL

    MrCoffeeATL Member

    flex up pipe FTW, STI up pipe from ebay for cheap
     
  22. goixiz

    goixiz Active Member

    the solid ones are fine (IMHO) as long as when its installed you have no issues and dont have to stress or bend it to fit. If you have to do all that then there are stress point on the pipe nad then it will break.

    The flex joint is there so that if there are a small misalignment it wont be an issue. Even though its cast (engine) there are small misalignments and not all pipes are made the same.
     

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