Tuning/MPH Help

Discussion in 'PSI Superchargers Tech Questions' started by Flyboy68, Sep 20, 2010.

  1. Jp outlaw

    Jp outlaw New Member

    Joined:
    Aug 11, 2010
    Messages:
    9
    Likes Received:
    0
    The "limit" is when using the digi 7 by itself; it runs out of sufficient spark energy around 1900hp. - You're using the Mag44's energy and just using the digi 7 as a controller, thus it is not a problem.

    Did I hear of a new personal best of 4.8x? - Movin up, just gotta keep working with it.
     
    #21
  2. poolman

    poolman Member

    Joined:
    Dec 4, 2005
    Messages:
    114
    Likes Received:
    0
    You need to spin the blower more, around 30% . We went from 4.68 @ 156 to a 4.56 @167 . Also try a 4.10 gear if you can
     
    #22
    Last edited: Oct 20, 2010
  3. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,706
    Likes Received:
    132
    ignition

    Have you sent your ignition system to David Leahy to be tested recently? Weak ignition will run like crap no matter what you do.

    How much of a change on your main jet is a tenth on your AFR? Is that leaning on it .005 at a time, .010, .020?

    Easiest way to check if your leanout is working properly is to disconnect where it returns into and let it run into a bucket. I don't know what you have triggering it, whether it's off the tbrake or wide open throttle switch, but do what you need to do on the jackstands to make the timer fire like it was on a run, then see if fuel is actually coming out of the return line. You can also do this with air if you can test the timer w/o the motor running.

    Back to ignition...when's the last time you changed wires and coil wire. I don't think a coil wire should make more than 10 runs. It's fired 8 more times than the rest. What about grounds? Head to head? Do all grounds lead back to a common grounding point?

    Cap and rotor lately? That's one of the cheapest parts on the car. Should be changed with coil wire it's so cheap.

    You don't have a fuel filter on the car that's clogged or something?

    I talked to a guy the other day that was told he had a 48 degree block turns out it was 45, so he had the wrong cam in it, put the right cam in it and went from bottom of the pack car to the winners circle.

    Back to the original question. You're either not leaning on it enough or you have something wrong, more than likely in the ignition.
     
    #23
  4. Alkydrag

    Alkydrag Sr. Dragster

    Joined:
    Dec 24, 2003
    Messages:
    351
    Likes Received:
    1
    I've never run into a situation of a 45 degree cam in a 48 degree block. But I would think if your checking the cam to make sure it's the right one, it would show up during this time. Whenever I degree a cam off cylinder 1, I check both intake and exhaust for lift, lobe seperation and timing. Then I check cylinder no. 6 for the same specs. If there not right, then the cam goes back.
     
    #24
  5. Flyboy68

    Flyboy68 Member

    Joined:
    Mar 26, 2006
    Messages:
    565
    Likes Received:
    0
    JP>thanks, it was a personal best, 4.75 @ 150. We turned the blower up from 27% to 35%. I think it helped. Made only 32lbs, but didn't drop off at the shift.

    Will>we had 16 runs on the wires...coil wire was new. Usually when we bump the afr say from 4.5 to 4.6, a lot of times it calls for the same pill, or mayb .005" bigger due to weather. I don't have a flow meter, but i don't notice a pressure drop when the hi-speed comes in. It's on a timer so we could check it in the pits...but at idle we're not make the same pressure as it does at 6000 or so when it comes in. We're using a Nitrous Fuel solenoid...so i'm not sure it's turning on w/ 80lbs of fuel pressure. I can't take the line off because the solenoid is about level w/ the top of the tank...it'll have fuel in it from the tank. We're running 14 gauge wire from each head to the coil. Same cap and rotor..will probably get new this winter (we're done for the season). Haven't ck'ed the fuel filter yet.

    Thanks for the ideas, 150 just seams a little low for a 4.75. We thought about going to a 2 speed w/ a taller gear.
     
    #25

Share This Page