Results 1 to 24 of 24
  1. #1
    Committee, Moderator Matt Cole's Avatar
    Join Date
    Sep 2008
    Location
    Durham
    Posts
    5,259
    Post Thanks / Like

    3 inch Exhaust?

    Has anyone produced a 3" full exhaust system for the GTT? I'm looking at the possible future benefits (if any) with my setup and possibly ditching the side exit in favour of a decent full system.

  2. #2
    Committee, Treasurer, Memberships admin Ian S's Avatar
    Join Date
    Sep 2000
    Location
    Essex
    Posts
    5,832
    Post Thanks / Like

    Re: 3 inch Exhaust?

    CTM / bigjimracing.co.uk did a turbo to rear exit 3 inch system for one of their 5GTT's. Was a years ago though.

    I have an idea that Mike Spencer had Simpsons exhausts make a 3 inch one for that ill fated green/purple EFI 5GTT.

  3. #3
    Committee Member
    North West Regional Area Rep
    BluntyR5GTT's Avatar
    Join Date
    Nov 2009
    Location
    Stoke-on-Trent
    Posts
    3,143
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Longlife could make u one mate. Hearing alot of good things about them atm

  4. #4
    Non-member philr5t's Avatar
    Join Date
    Dec 2008
    Location
    tadworth
    Posts
    1,881
    Post Thanks / Like

    Re: 3 inch Exhaust?

    i had big jim make me a 3 inch down pipe straight from the turbo and i also have powerflow waiting for me to get the car down to them to make the rest of the 3 inch exhaust mine is a sidey though

  5. #5
    Committee Member Sparkie's Avatar
    Join Date
    Aug 2008
    Location
    Tipton
    Posts
    3,085
    Post Thanks / Like

    Re: 3 inch Exhaust?

    it will rattle over the rear beam. the gap it has to fit through will be uber tight (left to right gap)....

    best check before getting it made?

  6. #6
    Non-member philr5t's Avatar
    Join Date
    Dec 2008
    Location
    tadworth
    Posts
    1,881
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by Sparkie View Post
    it will rattle over the rear beam. the gap it has to fit through will be uber tight (left to right gap)....

    best check before getting it made?
    i take it you mean it will rattle for a rear exit exhaust mate

  7. #7
    Non-member markey b's Avatar
    Join Date
    Jan 2003
    Location
    Bury St Edmunds
    Posts
    3,126
    Post Thanks / Like

    Re: 3 inch Exhaust?

    my bro had a 2.5" rear exit on his and it was 'snug' over the rear beam

  8. #8
    Non-member philg's Avatar
    Join Date
    Aug 2009
    Location
    Newcastle
    Posts
    2,211
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Bloody hell mat how much power do you want to push out of it

  9. #9
    Committee, Moderator Matt Cole's Avatar
    Join Date
    Sep 2008
    Location
    Durham
    Posts
    5,259
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by philg View Post
    Bloody hell mat how much power do you want to push out of it
    Ha, i was thinking 'future proof' if i decide to remove the ill fitting side exit and replace with something meaty. It may be over kill i dont really know as i aint done any calcs to determine any benefit. I had heard that the Evo's and Impreza etc seem to upgrade to a 3" but not sure if its tuner BS or any real gains to be had.

    A discussion on here would be nice!

  10. #10
    Non-member Mart's Avatar
    Join Date
    May 1996
    Location
    Pie & mash shop
    Posts
    4,732
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Imho, 3" bore isn't required until at least 400hp (assuming turbo application), and even then, that would then depend more so on overall length of the system, how many bends (and what angle they are), etc.

  11. #11
    Non-member philg's Avatar
    Join Date
    Aug 2009
    Location
    Newcastle
    Posts
    2,211
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by Mart View Post
    Imho, 3" bore isn't required until at least 400hp (assuming turbo application), and even then, that would then depend more so on overall length of the system, how many bends (and what angle they are), etc.
    I agree with Mart Mat. Straight as possible is always best. I upgraded from a 2.5 to a 3" and noticed no difference whatsoever.

    I think with evos and scoobs like mart said most are running 350hp+. I was also told a larger exhaust can give you larger hp but can negative affect on how the car make torque.

    What size is on now mat?

  12. #12
    Non-member raj's Avatar
    Join Date
    Feb 2001
    Location
    Rohtang pass
    Posts
    2,595
    Post Thanks / Like

    Re: 3 inch Exhaust?

    just a thought....
    why not have the 3"exhaust system up to the middle of the car..at this point fit an exhaust cutout valve?
    if you get the actuator type you can the have it flip open at the same time your turbo starts spooling. anything before boost and the valve will not open resulting all gasses exiting in the normal manner,rear or sidey.

  13. #13
    Non-member TNT ANDY's Avatar
    Join Date
    Sep 2008
    Posts
    2,614
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Rule of thumb - 1inch per 100bhp

  14. #14
    Non-member DK DEVELOPMENTS's Avatar
    Join Date
    Nov 2008
    Location
    LONDON
    Posts
    162
    Post Thanks / Like

    Re: 3 inch Exhaust?

    My exhaust is 3inch side exit was fabricated by simpson race exhausts.
    will get pick of complete exhaust the weekend.
    Attached Images Attached Images  

  15. #15
    Non-member rs250nut's Avatar
    Join Date
    Oct 2008
    Location
    Learning you can't teach stupid.
    Posts
    2,091
    Post Thanks / Like

    Re: 3 inch Exhaust?

    So for 700hp we need a seven inch exhaust

  16. #16
    Committee, Moderator Matt Cole's Avatar
    Join Date
    Sep 2008
    Location
    Durham
    Posts
    5,259
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by philg View Post
    I agree with Mart Mat. Straight as possible is always best. I upgraded from a 2.5 to a 3" and noticed no difference whatsoever.

    I think with evos and scoobs like mart said most are running 350hp+. I was also told a larger exhaust can give you larger hp but can negative affect on how the car make torque.

    What size is on now mat?

    It's a 2.5" tiger side exit Phil. I guess plentifull for now, but is it any good for over 300bhp? TBH i might not even have enough room as its tight for the down pipe as it is.

  17. #17
    Non-member J$£5GTT's Avatar
    Join Date
    Oct 2008
    Location
    THE BAT CAVE
    Posts
    3,560
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by rs250nut View Post
    So for 700hp we need a seven inch exhaust

  18. #18
    Non-member philg's Avatar
    Join Date
    Aug 2009
    Location
    Newcastle
    Posts
    2,211
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by MATT C Ringworm Tuning View Post
    It's a 2.5" tiger side exit Phil. I guess plentifull for now, but is it any good for over 300bhp? TBH i might not even have enough room as its tight for the down pipe as it is.

    Sound like what you have will be fine and alot less hassel, you just dont want it to be overkill, (like most of my car ).

    Whats ashy got on his, is his car not running over 300hp?


    phil

  19. #19
    Committee, Moderator Matt Cole's Avatar
    Join Date
    Sep 2008
    Location
    Durham
    Posts
    5,259
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by philg View Post
    Sound like what you have will be fine and alot less hassel, you just dont want it to be overkill, (like most of my car ).

    Whats ashy got on his, is his car not running over 300hp?


    phil
    Nothing at the moment because it's in bits!!

    He's rebuilding his lump for a possible 300bhp target. TBH plentifull in a 5! I think he was using a 2.5" side exit too.

  20. #20
    Non-member raj's Avatar
    Join Date
    Feb 2001
    Location
    Rohtang pass
    Posts
    2,595
    Post Thanks / Like

    Re: 3 inch Exhaust?

    any ideas on what full 2.5" rear exit systems are on the market.? im starting to get annoyed with this side exit.

  21. #21
    Non-member Duncan Grier's Avatar
    Join Date
    Mar 2004
    Location
    Coventry
    Posts
    949
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by Mart View Post
    Imho, 3" bore isn't required until at least 400hp (assuming turbo application), and even then, that would then depend more so on overall length of the system, how many bends (and what angle they are), etc.


    Well on the vx220 turbo 2.5 is fine to upto about 300bhp, stick a decent 3" and goes up 10bhp of the same spec engine / turbo

    The exhaust is not long but 2 180deg bends - I would not think on a GTT engine there would be much to gain from 3inch over the 2.5

    I have also seen some larger exhausts loose power in places

    Would imagine its a bit tight to get a full rear 3inch on the 5 but def possible and can always do what they do for some of the vag downpipes in tight areas of splitting into 2 smaller pipes and back to the larger, of squeeze the bad boy

    DG

  22. #22
    Non-member Spooky's Avatar
    Join Date
    Sep 2001
    Location
    SW PMT HQ
    Posts
    2,289
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by DK DEVELOPMENTS View Post
    My exhaust is 3inch side exit was fabricated by simpson race exhausts.
    will get pick of complete exhaust the weekend.
    Ive just ejaculated...

  23. #23
    Non-member tubby5's Avatar
    Join Date
    Sep 2008
    Location
    york
    Posts
    279
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Quote Originally Posted by Spooky View Post
    Ive just ejaculated...
    I would hate to think what the pics are gonna make you do

  24. #24
    Committee, Moderator Matt Cole's Avatar
    Join Date
    Sep 2008
    Location
    Durham
    Posts
    5,259
    Post Thanks / Like

    Re: 3 inch Exhaust?

    Well I think I'll look into 3" and report back! Cheers

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •