Low gear lean out for a 206D

Discussion in 'PSI Superchargers Tech Questions' started by BUTCH, Apr 27, 2011.

  1. BUTCH

    BUTCH Member

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    Hi all, I want to install a low gear out on my fuel system, I have a valve that will flow the same as a .085 main jet, I have it hooked up to CO2 from my 1st to 2nd shift pot from my lenco so it will close the valve and fatten up the motor in 2nd gear, my fuel pressure at 8000 rpms is 162psi. I run my set up pretty fat mostly no cad off the face of the plugs after a run, EGT's are 900 to 950 at the end of the run. stage temps are 675 to 700.

    1-Do I need a popet on it, if so, were should I have the cracking psi set?

    2-Is it ok to start out with about a .045 jet?

    any other info you can think of?

    Thanks again for all of the help!!!!

    Butch
     
    #1
    BUTCH, Apr 27, 2011
  2. Don Onimus

    Don Onimus New Member

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    lean out

    You can run a N/O Whitney valve to the air line from the tower or the line from the 1/ 2 shift button. Look and see what your PSI book say's about the jet for your appl. KISS Keep ir simple Don
     
    #2
    Don Onimus, Apr 27, 2011
  3. Mike Canter

    Mike Canter Top Dragster
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    No you do not need a poppet if it is a solenoid that you can turn on or off. The smaller the jet the richer the mixture and the less power you will have during launch and first gear. You can start out with a 45 jet and work your way up 10 sizes at a time. Keep that driveshaft RPM up or you will have shake. You need to be above 2600 RPM at .5 seconds into the run. If lower than that then shake is coming.
     
    #3
    Mike Canter, Apr 27, 2011
  4. BUTCH

    BUTCH Member

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    Mike Canter is the man!!!! I will keep a eye on the drive line rpm .5 into the run to make sure it is above 2600 rpm. What would be a good staging EGT temp to look for?

    thanks so much for the help!!!!

    Best regards

    Butch
     
    #4
    BUTCH, Apr 27, 2011
  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    more to it...

    I usually run a check roughly equal with your idle check to keep the jet from free flowing at idle. If you are running a normally open circuit that closes on the 1-2, this jet will be open 100% of the time and increase your head temp depending on how big of a jet you have in it.

    Also, where you place the leanout is very important. If you put the leanout in front of the BV, your leanout jet will have a bit part of how rich or lean you are at stage, if it's behind the BV, it won't flow as much until after WOT.
     
    #5
    Will Hanna, Apr 27, 2011
  6. Mike Canter

    Mike Canter Top Dragster
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    An average EGT of 625*-675* at stage would be good.
     
    #6
    Mike Canter, Apr 27, 2011
  7. Don Onimus

    Don Onimus New Member

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    lean out

    PSI shows it coming off a port on the fuel shut off. Also run a jet between a 40 and 80 depending how aggressive you want to be. set the pressure with a spring just stiff enough to hold the jet in. Like Will started in his post. Don
     
    #7
    Don Onimus, Apr 27, 2011
  8. rb0804

    rb0804 Active Member

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    Is the valve a normally open or normally closed valve? I like to run a normally closed valve and open it up at the hit of the throttle, because like stated above if you run a normally open valve it will have an effect on your stage fuel flow and your head/egt as you change the jet up or down to be more/less aggressive. Personally I like to have the idle/stage adjustment separate because it is one less thing to take into account when making changes. For example if you change the jet to get more aggressive, and then start turning on the barrel valve to lean it out at stage, you could over do yourself. Conversely, if it is already open at the hit, you don't have to worry about the 'transition' into dumping fuel (possibility of upsetting the car).
     
    #8
    rb0804, Apr 27, 2011
  9. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    nc vs no

    It just depends on when you want the power. if you open a leanout off the WOT, the motor is really not going to see the effect of that jet for about .25.
     
    #9
    Will Hanna, Apr 28, 2011
  10. BUTCH

    BUTCH Member

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    All, thanks for all of the great feedback!!!, The valve I have is a n/o valve that closes when co2 is applied, I have the fuel system pretty close to were i like it, so I really like the idea of having the lean out behind the BV on a popet that is just above the cracking pressure of the idle check, so if I am under standing Will correctly, the lean out will not be working at a idle? and when I bring up the rpms at stage it will help to clean up the motor and make more power through first gear? does this sound correct? If anyone has a picture of this plumbing and could e mail it to me that would be great. spmi@sonic.net

    thanks again for all of the help.

    Butch
     
    #10
    BUTCH, Apr 29, 2011
  11. Mike Canter

    Mike Canter Top Dragster
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    Yep, that is exactly right with a NO valve. Like Will said if you don't put a poppet in it then you will be lean at idle and the EGTs will get too high before you stage and run. You can vary your staging EGTs by the idle setting on the BV.
     
    #11
    Mike Canter, Apr 29, 2011
  12. shawn davis

    shawn davis Member

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    I had mine plumbed off the shut off with a 40 lb poppet, n.o. valve, closed with air on the second gear shift. had a .055 jet, ran it back to back with the valve and without, ran exactly the same 330 though
     
    #12
    shawn davis, Apr 29, 2011
  13. Mike Canter

    Mike Canter Top Dragster
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    Shawn, without that Low Speed Lean oUt a lot of cars will go into tire shake in first gear. A 55 jet is not very big especialy with a 40 lb poppet in series. So if you have 150 lbs of fuel pressure the going through that jet is only seeing 110 lbs of fuel pressure. I would say you need a bigger jet in the lean out. It also depends on the overall fuel curve. If you are running too rich then the Low Speed will not have as much effect.
     
    #13
    Mike Canter, Apr 29, 2011
  14. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    poppet

    With NO valves against a 20ish poppet it takes a 65 to really get the cars attention and make it do something.
     
    #14
    Will Hanna, Apr 29, 2011
  15. BUTCH

    BUTCH Member

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    Low gear lean out

    All, thanks for all of the great feed back, I think I have a real good place to start, I will start off on the safe side and keep my eye's on the wheel speed, EGT's and just see how the car reacts, and then get a little more aggressive, we will be testing in a few weeks, I will let you know how it goes.

    Thanks again to all and ITA !!!!

    Butch
     
    #15
    BUTCH, May 3, 2011

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