Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 24
  1. #1
    Fast & Loud meeper's Avatar
    Join Date
    Jul 2005
    Location
    West Grove, PA
    Posts
    5,019
    +1
    54

    Engine Vacuum and FPRs

    If anyone is having issues with the vacuum playing with your fuel pressure and making it harder to tune i found a solution while installing my new fuel system on Grand Cherokee SRT. available from mcmaster carr, it will screw into your boost source and only allow 1psi or greater to affect fuel pressure, no vacuum

    http://www.mcmaster.com/#7768k25/=r5zwm8


  2. #2
    mibunkerking's Avatar
    Join Date
    Aug 2008
    Location
    Jax,Fl
    Posts
    2,259
    +1
    117
    Good find. I just had to switch to static because the vacuum was sending my afr's into the high 14's.

  3. #3
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Location
    Davison, Mi
    Posts
    4,494
    +1
    476
    you can use a check valve and not get any vaccume

  4. #4
    Boost addict hotbird's Avatar
    Join Date
    Jul 2011
    Location
    Southern WI
    Posts
    5,503
    +1
    681
    Cant you just install a fitting on the charger side of the throttle blade?
    Then its boost only referance.

  5. +1 by:


  6. #5

    Join Date
    Sep 2010
    Location
    South Florida
    Posts
    1,599
    +1
    123
    Quote Originally Posted by hotbird View Post
    Cant you just install a fitting on the charger side of the throttle blade?
    Then its boost only referance.
    That's what I did when I had a RRFPR and it worked perfect.

  7. #6
    Ken62465's Avatar
    Join Date
    Apr 2011
    Location
    Gardner, MA
    Posts
    582
    +1
    48
    Stupid question....if the fitting is on opposite side of the throttle plate how is this vacuum created?

  8. #7
    Boost addict hotbird's Avatar
    Join Date
    Jul 2011
    Location
    Southern WI
    Posts
    5,503
    +1
    681
    At idle the motor sucks air creating a vacuum due to the throttle blade being mostly closed.

  9. #8
    Ken62465's Avatar
    Join Date
    Apr 2011
    Location
    Gardner, MA
    Posts
    582
    +1
    48
    ahh..don't know why that light bulb didn't go off on that one. Thanks..this was good info since a rrfpr is in the near future.

  10. #9
    Boost addict hotbird's Avatar
    Join Date
    Jul 2011
    Location
    Southern WI
    Posts
    5,503
    +1
    681
    I have always had good luck running them from the intake, but every setup is different, and may require this boost only reference.

  11. +1 by:


  12. #10
    Ken62465's Avatar
    Join Date
    Apr 2011
    Location
    Gardner, MA
    Posts
    582
    +1
    48
    If you were to install a fitting for boost only reference where on opposite side of throttle plate would the preferred location be? Looking at the throttle body it sure doesn't look like there's any room where the sc hose ends to the plate.

Page 1 of 3 1 2 3 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Engine removal and installation links
    By Smitty in forum Yamaha How To & FAQs
    Replies: 3
    Last Post: 01-04-2013, 08:28 PM
  2. engine management and control
    By spaulding in forum Kawasaki PWC Performance (4-stroke)
    Replies: 13
    Last Post: 10-03-2007, 06:38 AM
  3. Engine surges and RPM difference
    By mrcfjf in forum Sea Doo Sport Boats
    Replies: 2
    Last Post: 06-13-2007, 06:21 PM
  4. New reverse engine installed, and pics of new test tank.
    By Rodneyae in forum Polaris Open Discussion
    Replies: 4
    Last Post: 05-22-2007, 05:31 PM
  5. Engine Boggs and dies near 4000
    By gvnitup in forum Polaris Open Discussion
    Replies: 9
    Last Post: 05-13-2007, 04:25 PM

Posting Permissions

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