Join Today
Results 1 to 14 of 14
  1. #1
    Senior Member
    This user has no status
    chrjen's Avatar
    Join Date
    Sep 2006
    Posts
    170
    Thanks
    1
    Thanked 2 Times in 2 Posts

    Single or double piston Dump Valve ?

    Can anyone please explain to me, what will happen if I use a single piston Dump on my T5R ?

    I got a nice one from my friend, but I am unsure whether it will work.

  2. #2
    Senior Member
    Glad im Back -D
    cameron's Avatar
    Join Date
    Jul 2008
    Location
    Oldham, Lancashire
    Posts
    6,061
    Thanks
    983
    Thanked 604 Times in 533 Posts
    Single piston DV's have a tendancy to jam open, and will cause a big problem.

    Go Twin Piston everytime if you really want one

    Something like a Bailey DV26


    1998 C70 T5 GT Auto, 68k, FVSH, Immaculate inside and out, only mod - poly top mount, its Yellow and no pete i didnt paint it, lol

  3. #3
    Senior Member
    This user has no status
    chrjen's Avatar
    Join Date
    Sep 2006
    Posts
    170
    Thanks
    1
    Thanked 2 Times in 2 Posts
    what exactly is BIG PROBLEM ?

  4. #4
    Senior Member
    Glad im Back -D
    cameron's Avatar
    Join Date
    Jul 2008
    Location
    Oldham, Lancashire
    Posts
    6,061
    Thanks
    983
    Thanked 604 Times in 533 Posts
    It would kill the Turbo due to not being able to dump the pressure.

    It could bend the fans or the rod and you'd need a new turbo.


    1998 C70 T5 GT Auto, 68k, FVSH, Immaculate inside and out, only mod - poly top mount, its Yellow and no pete i didnt paint it, lol

  5. #5
    Senior Member
    This user has no status

    Join Date
    Sep 2006
    Posts
    645
    Thanks
    28
    Thanked 115 Times in 99 Posts
    Quote Originally Posted by cameron View Post
    It would kill the Turbo due to not being able to dump the pressure.

    It could bend the fans or the rod and you'd need a new turbo.



  6. #6
    Senior Member
    This user has no status
    gareth's Avatar
    Join Date
    Oct 2006
    Location
    Limerick, Ireland
    Posts
    175
    Thanks
    16
    Thanked 18 Times in 14 Posts
    I think it has more to do with single piston ones opening with idle vacuum and dumping metered air, thus confusing the air flow meter and affecting how the car idles - i.e. like a Belle minimix -and for a 5cyl that's not good.!!.
    As for not dumping excess pressure and damaging the turbo.... no chance. Less than two bar pressure in there.
    I ran a Forge blank plate and no dv on my first 855 T5 for about two months and it sounded wicked and no damage either and no real visible sign of compressor stall either.
    Sounds like this too. Although this was not my car the "chirping" was almost identical:
    [ame="http://www.youtube.com/watch?v=EnjUgYVwHSc&feature=related"]http://www.youtube.com/watch?v=EnjUgYVwHSc&feature=related[/ame]
    Last edited by gareth; Monday 23rd March 2009 at 10:19.

  7. #7
    Senior Member
    Glad im Back -D
    cameron's Avatar
    Join Date
    Jul 2008
    Location
    Oldham, Lancashire
    Posts
    6,061
    Thanks
    983
    Thanked 604 Times in 533 Posts
    Only stating what ive been told by another VPC member.

    Wrong or right i still wouldnt use a single piston DV.

    Quote Originally Posted by irf View Post


    1998 C70 T5 GT Auto, 68k, FVSH, Immaculate inside and out, only mod - poly top mount, its Yellow and no pete i didnt paint it, lol

  8. #8
    Senior Member
    This user has no status

    Join Date
    Feb 2006
    Posts
    628
    Thanks
    7
    Thanked 73 Times in 68 Posts
    The car will not idle with a single piston DV.

    Car's that run mass air flow sensors have to have a twin piston

    shaun

  9. #9
    Senior Member
    This user has no status
    gareth's Avatar
    Join Date
    Oct 2006
    Location
    Limerick, Ireland
    Posts
    175
    Thanks
    16
    Thanked 18 Times in 14 Posts
    i still wouldnt use a single piston DV
    I'll definitely second that.
    They do sound cool with none though I bet someone will say that is more likely to f up the turbo.

  10. #10
    Senior Member
    OH DEAR
    t5 pete's Avatar
    Join Date
    Jul 2008
    Location
    barnsley s.yorkshire
    Posts
    12,470
    Thanks
    2,138
    Thanked 3,711 Times in 2,752 Posts
    Quote Originally Posted by gareth View Post
    I ran a Forge blank plate and no dv on my first 855 T5 for about two months and it sounded wicked and no damage either and no real visible sign of compressor stall either.
    Sounds like this too. Although this was not my car the "chirping" was almost identical:
    http://www.youtube.com/watch?v=EnjUg...eature=related
    By not having a recirc or dv i would have though you would be causing the back pressure to stall the compressor and getting turbo chatter through the air filter i personally wouldnt use a set up like this but every one to there own.

  11. #11
    Senior Member
    This user has no status
    gareth's Avatar
    Join Date
    Oct 2006
    Location
    Limerick, Ireland
    Posts
    175
    Thanks
    16
    Thanked 18 Times in 14 Posts
    Hi Pete, I do agree that this is not something that should be used as a permanent set up.
    However I never really noticed any significant stall in terms of reduced performance but as I said I only ran the setup 'cos i knew the turbo was coming out anyway.It was already passing oil and smoking on idle. Aside from the already known wear there was no visible signs of damage on removal however the new one went in with a DV26 installed too.
    My point really was your turbo will not self destruct or anything nearly as catastrophic by using no dv or a single piston one.

  12. #12
    Senior Member
    This user has no status
    chrjen's Avatar
    Join Date
    Sep 2006
    Posts
    170
    Thanks
    1
    Thanked 2 Times in 2 Posts

    Dv

    If I leave the original recirc. valve on WITHOUT blanking it off as eg. Forge and others do in their kits, and then use this single piston DV - then there shouldn't be any idle problems or...?

    This would just dump air two places instead of one - would it work ?

  13. #13
    Senior Member
    This user has no status
    gareth's Avatar
    Join Date
    Oct 2006
    Location
    Limerick, Ireland
    Posts
    175
    Thanks
    16
    Thanked 18 Times in 14 Posts
    I'd say there are three real options for you: 1. Leave as standard, 2. Blank standard and fit something like a DV26, 3. Fit a "high performance recirculating i.e non atmospheric, dump valve like this; http://www.forgemotorsport.com/conte...roduct=FMDV006

  14. #14
    Senior Member
    This user has no status
    T5arrrgghh's Avatar
    Join Date
    Mar 2009
    Location
    Aberdeen
    Posts
    123
    Thanks
    15
    Thanked 2 Times in 2 Posts
    what about option 4 reverse ic piping and an hks ssqv? hmmmm i think that is the way i will go. i have mental turbo chatter, sounds awesome but needs sorted i guess.
    1996 850 T5r, RICA 304, samco radiator, vac lines and boost hoses, powerflex bushes on wishbones and top engine mount, cross drilled and grooved discs, HID's, V70 rear lights, K&N panel in slightly drilled box, powerflex anti roll bar bushes, xc90 spring mounts stage 0, 200,300 miles


 

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
This website uses cookies
We use cookies to store session information to facilitate remembering your login information, to allow you to save website preferences, to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.
     
ipv6 ready