Standard exhaust with turbo, restrictive?

  1. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #1
    Would the standard exhaust on a vtr be too restrictive with the spec i'm going for? T28 turbo, 2" boost pipes, standalone management etc, around 12-15 psi, or would i be better off going for a custom 2.5" exhaust?
  2. Established Member Joined: Nov 2010 manchester Posts: 2099 2000 1.6 furio
    #2
    doesnt the standard exhaust restrict the standard engine
    correct me if im wrong
  3. Established Member Joined: Jun 2011 Bridgnorth (Shropshire) Posts: 2001 Jdm Dc2 Integra
    #3
    you will need a custom 2.5" exhaust system.... anything over 160ish bhp and you need a minimum of 2.25" really

    but make sure non of the bends in it are restricting it, as some custom exhaust manufactuarers fabricate shit quality bends that reduce the bore size
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  4. Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)
    #4
    what power will it roughly make? If under 180bhp a 2" bore would probably be ok. I don't think it really matters though if you oversize after the turbo as pulse tuning does not apply so most people just fit as big as possible.
    I'd be using a 2.5" bore on an engine over 230-240 bhp.
  5. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #5
    Quote:
    Originally Posted by KamRacing View Post
    what power will it roughly make? If under 180bhp a 2" bore would probably be ok. I don't think it really matters though if you oversize after the turbo as pulse tuning does not apply so most people just fit as big as possible.
    I'd be using a 2.5" bore on an engine over 230-240 bhp.

    going towards the 200bhp mark, i think i'll get a 2.5" system made up
  6. Regular Poster Joined: Jul 2012 Dundee Posts: 488 Looking for 16v furio.
    #6
    Restrictive? Extremely
  7. Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B
    #7
    if your only going for 200bhp id use a different turbo tbh

    youll get a lot of lag out of a t28 which needn't be there if your only aiming for that power
  8. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #8
    Quote:
    Originally Posted by blackie_2k5 View Post
    if your only going for 200bhp id use a different turbo tbh

    youll get a lot of lag out of a t28 which needn't be there if your only aiming for that power
    Hmm, mabye i'm better off using a t25 like yours? i'm sort of basing my spec around yours at 15 psi though, was you pushing it with that turbo?
  9. Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B
    #9
    yeah i run t25 at 15psi

    13psi on a t28 would probs be about 240bhp
  10. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #10
    Quote:
    Originally Posted by blackie_2k5 View Post
    yeah i run t25 at 15psi

    13psi on a t28 would probs be about 240bhp
    quite like the sound of that think i might go all out and stick with the t28
  11. Super Moderator Joined: Nov 2009 Cambridge(ish), UK. Posts: 10581 BMW 5x M50d.
    #11
    as blackie said. drop down a turbo is you want something fun to drive on real roads with around a bar of boost. The t25 won't like more than a bar, and the t28 will take a little more, but at the cost of spool.

    If you're planning either a t25 or t28 with a bar or more of boost, the standard exhaust will be very restrictive. Sack it off. Go 2.5" incase you want anything more in the future.

    2.5" is good for up to around 350bhp. More than that and it starts to become quite restrictive (although I made 400bhp on my 2.5" a 3" would have made more).
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  12. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #12
    While were on the subject of exhausts, can anyone guess me a rough estimate how much it would cost for a 2.5" system to be made up for me?

    See i do have access to air tools/grinders etc and have someone to do all the welding, surely i can't go wrong as long as i use mandrell bends and follow the standard exhaust?
  13. Established Member Joined: Jun 2011 Bridgnorth (Shropshire) Posts: 2001 Jdm Dc2 Integra
    #13
    It will cost roughly 300-400 to have a custom made one from turbo back, it is possible to make your own too, but you would have to make sure that the bends and the silencers aren't restrictive either, and I'd imagine that the silencers and flanges would be fairly difficult to weld too unless your competent in welding
  14. Established Member Joined: Aug 2009 King's lynn Posts: 2073 Turbocharged vtr
    #14
    Quote:
    Originally Posted by jones91 View Post
    It will cost roughly 300-400 to have a custom made one from turbo back, it is possible to make your own too, but you would have to make sure that the bends and the silencers aren't restrictive either, and I'd imagine that the silencers and flanges would be fairly difficult to weld too unless your competent in welding
    Well I know a welder who can weld anything i need, i'd just need to tack weld it so i know it's in the right place, would be alot cheaper than them sort of prices