fuel flow

Discussion in 'PSI Superchargers Tech Questions' started by d.kirkalkyburner, May 2, 2009.

  1. d.kirkalkyburner

    d.kirkalkyburner Member

    Joined:
    Sep 4, 2004
    Messages:
    187
    Likes Received:
    0
    went to test and tune today started out with a .0665 main jet made a pass flow meter says it used 10.32 and 169 psi at 4000 rpm then switched to a
    .0610 main jet made a pass and got 10.34 and 172 psi at 4000 rpm just wondering if there is any reason it only added .02 GPM instead of the .1528
    GPM that is the difference in flow between the 2 sizes at 150 psi on flow sheets. Thanks
     
    #1
    d.kirkalkyburner, May 2, 2009
  2. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    The first question is can you make two runs without changing anything and have the fuel flow exactly the same on both runs. Have you tried that?
     
    #2
    Mike Canter, May 2, 2009
  3. d.kirkalkyburner

    d.kirkalkyburner Member

    Joined:
    Sep 4, 2004
    Messages:
    187
    Likes Received:
    0
    Mike it did the same on the bench , thats why i tried it at the track to see if it reacted the same before asking the question, the only difference was that the actually flow numbers changed due to 2 differnet meters i suppose but the GPM difference was the same the .02 between the 2 main when changed thanks DARRIN
     
    #3
    d.kirkalkyburner, May 2, 2009
  4. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Then my next question would be are the main jets you are using flow calibrated or are they "as is" Enderle bypass jets? I have seen those kind of inaccuracies in non flow calibrated jets. I have done tests on four 80 jets and four 60 jets and it is crazy the difference the same jet numbers flow. All my jets are flow calibrated by Ralph Gorr.
     
    #4
    Mike Canter, May 2, 2009
  5. Dale Finch

    Dale Finch Member

    Joined:
    Dec 29, 2004
    Messages:
    271
    Likes Received:
    2
    I agree with Mike, impossible to seriously tune a race car without flowed nozzles and jets, period.
     
    #5
    Dale Finch, May 2, 2009
  6. JRB

    JRB Guest

    All we use is flowed stuff from Enderle, which we get from RBS. They are a little more pricey, but in time, can save you a bunch of money on melted aluminum.:cool:
     
    #6
    JRB, May 2, 2009
  7. d.kirkalkyburner

    d.kirkalkyburner Member

    Joined:
    Sep 4, 2004
    Messages:
    187
    Likes Received:
    0
    Mike and Others they arent exactly flowed we did hole gauge them and thats how we got the .0665 and the .0615 dimensions one was a 65 the other a 60 as marked
     
    #7
    d.kirkalkyburner, May 2, 2009
  8. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Hole gauging doesn't do a thing for flow accuracy at the extent you want. It does tell you that you have the right size hole and the right size hole puts the flow withing a range but a slight nick or burr will change that flow more than the amount you are looking for.
     
    #8
    Mike Canter, May 3, 2009
  9. WIZBANG

    WIZBANG Member

    Joined:
    Nov 8, 2004
    Messages:
    761
    Likes Received:
    2
    Depends on the "chamfer" or "radius" on the leading edge of the hole. I use the Hilborn, Enderle, Kinsler style drop in pills. We flow them numbers showing and not showing, that way we get two pills from each one ! You have to have the nozzles and pills flowed !
     
    #9
    WIZBANG, May 3, 2009
  10. Dale Finch

    Dale Finch Member

    Joined:
    Dec 29, 2004
    Messages:
    271
    Likes Received:
    2
    In fact the company that flowed ours says you can play with the chamfer and run numbers drills through them to adjust them.
     
    #10
    Dale Finch, May 3, 2009
  11. WIZBANG

    WIZBANG Member

    Joined:
    Nov 8, 2004
    Messages:
    761
    Likes Received:
    2
    Thats exactly how you make up a "set" of nozzles. The fuel car has one set of "constants" in it. So we have to play around to actually get a set that all flow the same. You can just touch the chamfer with very little pressure on a tool and it will change the flow a half a number !

    Have any of you not using "flowed" pills, actually had an engine run the the opposite way you intended the tune up to go, when you changed the pill size ? You thought the number was bigger or smaller, but the tune up went the opposite way. Thats because the hole can be bigger or smaller , but the flow can actually be the opposite due to the leading edge of the hole,,,,, it's called the " hysteresis"
    ( sorry, not sure of the spelling ?)

    I will ask for Mike Canter to correct me here or help me explain it, please !
     
    #11
    WIZBANG, May 3, 2009
  12. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Dale, I would highly recommend not using a drill on a jet or changing the inlet or exit characteristics of the jet unless you have a flow bench to see the results. It is not as easy as one thinks. If you leave a burr or a ridge or a scratch in that jet it will flow more or less.
     
    #12
    Mike Canter, May 4, 2009
  13. Dale Finch

    Dale Finch Member

    Joined:
    Dec 29, 2004
    Messages:
    271
    Likes Received:
    2
    I agree Mike, sorry if I left that impression. That is what our bench guy tells me.
     
    #13
    Dale Finch, May 5, 2009

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM