Super Mag RF interference?

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by aafa760, Aug 27, 2018.

  1. aafa760

    aafa760 Member

    Joined:
    Jul 13, 2010
    Messages:
    74
    Likes Received:
    2
    Hello Everyone,
    Has anyone run a RPM system and Super Mag 4 I am getting crazy RF into the RPM readings Randy and I are trying different things but so far nothing has cleaned up the RPM signals.
    How about the wire change from solid core to suppressor type I know I had some huge issue when I tried suppressor on mag 5 and Blown Nitro did not work well. But this is for blown FED on Alcohol .

    Battery and Computer are 8 ft from mag and coil.
    I am using a single magnet in front hub as instructed by RPM 4 magnet pinon sensor single Clutch shaft sensor.
    The EGT look to be ok but the ERPM and DRPM and Fuel Flow are all over place. 4K on manual tach the RPM says 2-12K spikes o_O

    Bryan
     
    #1
  2. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,136
    Likes Received:
    73
    Did you say you triedsuppressor core plug wires with the Super Mag. EGT cables are a great antenna make sure the braided shields are grounded.
     
    #2
  3. bandit496

    bandit496 Member

    Joined:
    May 25, 2010
    Messages:
    155
    Likes Received:
    2
    We had the SM4 and SM+ with the RPM unit on blown and turbo BBC. We use a four magnet hub. Measure RPM, fuel pressure, boost, turbo back pressure, oil pressure, and EGT. Did nothing special to the wires. The RPM, boost, fuel pressure and back pressure wires run within a foot of the plug wires and closer. The enclosure was all steel ( aluminum one didn't work). Used MSD solid core and RF wires . Our logger was only about 36 inches from the coil and mag. I am now using MSD 44 and no issues. Just my experience. JW
     
    #3
  4. aafa760

    aafa760 Member

    Joined:
    Jul 13, 2010
    Messages:
    74
    Likes Received:
    2
    Mike they have been ordered I will get them this week.
    The Egt are the most stable recordings they run right near the plugs wires.
     
    #4
  5. aafa760

    aafa760 Member

    Joined:
    Jul 13, 2010
    Messages:
    74
    Likes Received:
    2
    Bandit
    My box is an Aluminum one so you had to move to a Steel box ?
     
    #5
  6. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,136
    Likes Received:
    73
    EGTs are analog so RF doesn’t bother them but the braided shields act as an antenna to the RF going into the digital electronics in the RPM recorder
     
    #6
  7. bandit496

    bandit496 Member

    Joined:
    May 25, 2010
    Messages:
    155
    Likes Received:
    2
    Yes. I forget if we used the aluminum before switching, was 5 years ago, but obviously must have, or else why switch. I remember it was a "big" deal to refab out of steel because we work much easier with aluminum. Ours is mounted behind our seat on a thin steel sheet between the supports of our roll cage and then a fabbed steel cover shield held on with 2 dzuz clips. Battery and everything is covered. Steel is thin--maybe 1/32 or 1/16. jw
     
    #7
  8. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,136
    Likes Received:
    73
    The only difference between the steel and aluminum would be the steel could get a magnetic field. Most likely when you moved everything to the steel box you fixed a bad ground or added a better ground
     
    #8
    Mark Leigh likes this.
  9. SoDak

    SoDak Active Member

    Joined:
    Dec 29, 2006
    Messages:
    1,512
    Likes Received:
    3
    Since the common way to shut off an engine with a SM is to have a toggle switch in the cockpit that grounds the coil, you have a fairly long "noise antenna" in doing so. My intention is to put on a shielded/grounded kill wire this winter to minimize that.

    I've been told to mount the coil close to the mag so you can use a short coil wire, which I've done but don't have the computer back on to see if it helps.

    Spud Miller recommends Taylor suppression wires.
     
    #9
  10. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,136
    Likes Received:
    73
    Those Taylor wires should help if not fix the problem
     
    #10
    Mark Leigh likes this.
  11. Kramer Metal Fab Inc.

    Joined:
    Jul 28, 2008
    Messages:
    199
    Likes Received:
    3
    Are the Taylor suppression wires better for the SM and a computer than the MSD suppression wires?
    We still struggle to get good graphs on our fuel pressure, oil pressure and blower boost. I have done everything trying to move them as far from the mag as possible. SM4 was not an issue when we moved to an SM5 everything went crazy on the computer and we had to change everything. RF from the super mag is a pain.
     
    #11
  12. blowntrifive

    blowntrifive Member

    Joined:
    Mar 16, 2008
    Messages:
    155
    Likes Received:
    0
    Give Spud (FIE) 1-541-990-2485 a call, went threw this a few years ago, pretty loaded question and everyone says there wires are the best but proof is in the pudding as they say.!
     
    #12
  13. turbo69camaro

    turbo69camaro Member

    Joined:
    Nov 26, 2007
    Messages:
    230
    Likes Received:
    6
    How are you getting the rpm signal to the computer from the transformer ? i ran a SM with the inductive pick up from the coil wire think i also ran the autometer signal convertor box to the tach
     
    #13
  14. td3829mk

    td3829mk Member

    Joined:
    Dec 31, 2015
    Messages:
    119
    Likes Received:
    8
    the tach converter should be able to provide signal to multiple components. I run my data logger, tach and rpm activated switch off of that signal wire coming off the converter and it works well.
     
    #14

Share This Page