When is a Mag required?

Discussion in 'InsideTopAlcohol.com Tech Questions' started by Compresser, Mar 8, 2019.

  1. Compresser

    Compresser New Member

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    My question is at what point will a mag become necessary?
    I'm a newbie to blowers and such.
    Just to make it interesting it's EFI to boot.
    When I started out I had a 1071 street style blower and a -1 pump, MSD 7AL and a MSD
    HVAC coil. Ran a best of 6.80 @ 200.
    Moved up to a 1471HH blower and a Enderle 110 13 gallon pump.
    Boost jumped from 11 PSI to 23PSI.
    Still running the same ignition.
    I'm having a situation where the engine quits about 30' after the launch which I believe is due to a faulty fuel pump. Someone suggested the spark output may not be enough to handle the extra boost from the new blower.
    What is the opinion of the experts on this forum?
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    What plug gap are you using? When did it start quitting 30’ out? Did that happen when you swapped blowers or did it run ok for some time?
     
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  3. Bob Alberty Jr.

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    Following.

    I've been running a grid box and controller, billet distributor, ngk 10's at .018, and the hvc2 coil on a blown top dragster deal. Been sub 6 flat, 25lbs on the two step at 3500, and 42lbs in the lights at 8400.
     
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  4. Compresser

    Compresser New Member

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    Running NGK -10 gapped at .015
    When I first switched to the larger blower, pump etc it was very rich and did not run very fast/quick at all.
    Fixed the tuneup and this problem started.
    I suspect the fuel pump and have sent it to Enderle for check out.
    Bob Alberty what is the PN of your coil?
    This brings up another question. I don't have a pump saver return. I have thought the return regulator would serve that purpose.
    Any comments about the pump saver, yes or no?
    Thanks in advance
     
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  5. tc1216

    tc1216 Member

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    when the throttle is wide open, the return poppet or regulator works as it should. when you close the throttle in the lights, the fuel has nowhere to go, that's the design of the pump saver. I will bet you snapped the pump shaft, because the pump deadheads and snaps the shaft.
     
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  6. Bjs344

    Bjs344 Member

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    6.30s @ 2000 lbs here with a 7al2, ngk 10s gapped at .015. Never any sign of a problem. I put a new blower on once and shoved way too much fuel in being over cautious. It pushed the end seals out of the intake from all of the blow you but the 7al2 and the small coil still lit it off. Switched from the small coil the big one once and it repeated within a few thousandths.

    I would replace your master power switch if you haven’t already, double check all grounds, and think about changing your ignition power switch. If it was the fuel pump I would expect it to knock the blower off by now.
     
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  7. Mike Canter

    Mike Canter Top Dragster
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    I agree, if it was running lean because of the pump you would have many indications of that. As said I would look for an electrical problem.
     
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  8. Compresser

    Compresser New Member

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    Great comments and help.
    I don't think the pump shaft is snapped off as it would still run in the pits. I removed pump extension and inspected as well as removed front cover and inspected internally.
     
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  9. Dave Koehler

    Dave Koehler Member

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    EFI does not see the pressures MFI does.
    A large capacity return style regulator and return hose should handle it.
     
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  10. Neil Morley

    Neil Morley Member

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    I run a 555 bbc with a 14/71 HH retro blower at 39%OD makes 43 lbs boost and run the power grid ignition 7720 box with the 7730 controller with no issues, a mag isn’t necessary for what your trying to do!
     
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  11. Compresser

    Compresser New Member

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    Thank you for all of the replies
     
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