8973 to Power Grid 7730

Discussion in 'PSI Superchargers Tech Questions' started by Andy C, Dec 10, 2011.

  1. Andy C

    Andy C Member

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    Thinking of switching from 8973 to power grid 7730, we use MSD 44. Any input would be appreciated.
    Thanks.
     
    #1
    Andy C, Dec 10, 2011
  2. aj481x

    aj481x Member

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    Why ? :)
     
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    aj481x, Dec 10, 2011
  3. summitcb

    summitcb Member

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    I have both and have an 8973 for sale if someone wants it.

    The two biggest benifits of the 7730 box is the monitoring screen and the run safety settings. Also easier to hook up to laptop. They do most of the same things and not sure I would have made the change if I didn't have two cars and wanted the control systems to be the same.

    Steve
     
    #3
    summitcb, Dec 10, 2011
  4. Mike Canter

    Mike Canter Top Dragster
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    No doubt there is an advantage to the Power Grid's direct hookup to the Racepak for recording timing and retards and things. Also you don't have to use that @#$% serial to USB adapter to hook the Power Grid system up to your laptop like you do on a 8973. The wiring on the Power Grid is very simplified as compared to the 8973 because of the CAN-Bus system. Also with the Power Grid system there is a new shielded cable for the cranktrigger which is a lot better and helps eliminate random triggering.
     
    #4
    Mike Canter, Dec 10, 2011
  5. Andy C

    Andy C Member

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    Power Grid

    I am looking to have better recording of the timing map to race pack.
    Will we a be able to use a two step? We have 8147 box?
     
    #5
    Andy C, Dec 10, 2011
  6. Mike Canter

    Mike Canter Top Dragster
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    Yes, the 2 Step is in the Power Grid as in the 8973. You need to hook up the blue wire to either box either to the clutch switch or the transbrake so it has 12 volts to it when staged.
     
    #6
    Mike Canter, Dec 10, 2011
  7. aj481x

    aj481x Member

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    Does the Racepak show the actual engine timing? or just display the map?
     
    #7
    aj481x, Dec 10, 2011
  8. Andy C

    Andy C Member

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    timing

    Good point....
    Power Grid/Race pack will i be able to record actual timing or just display the programed map?
     
    #8
    Andy C, Dec 10, 2011
  9. summitcb

    summitcb Member

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    The only way to record timing is with the addition of a TDC sensor. I just sent my
    300sd back to have if calibrated. It will come back with a cable to a second crank tigger that will be lined up on TDC. I will then be able to record all timing events and the actual timing anywhere in the run.

    Steve
     
    #9
    summitcb, Dec 10, 2011
  10. Mike Canter

    Mike Canter Top Dragster
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    The only way to record actual timing in the past was via a separate crank sensor because the mag controller and the Racepak were two independent systems. Now with a redesigned mag controller and being integrating it into the Racepak on the bus you could record actual engine timing via other methods. Since the crank trigger pulse and the trigger pulse in the mag generator are coming into the mag controller you can use those which is the same as the older crank TDC sensor. You can also use the fiber optic cable to number one cylinder to provide actual timing information. I will check with MSD next week and see what we are actually recording
     
    #10
    Mike Canter, Dec 11, 2011
  11. Andy C

    Andy C Member

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    Pro grid

    Mike please let me know.
    Thanks.
     
    #11
    Andy C, Dec 11, 2011
  12. Blownalky

    Blownalky Top Sportsman

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    Are you talking about these items? This is what the 7730 Power Grid pumps off to the RacePak.


    [​IMG]



    This is what the 7730 stores.


    [​IMG]


    And, this is the individual cylinder timing screen showing just the #1 cylinder.

    [​IMG]

    So, what I get out of this is that the 7730 stores and forwards total timing so you don't have to buy that option for the RacePak. For the individual cylinder timing if you want to record it, you still have to do it via the RacePak which requires you to buy the timing function and run it on a V500. At least that is what I got from Todd when I was ordering mine. But, there is still the cam sync and ignition in and out that the 7730 records and I'm not sure if that can't be used to track each cylinder. Seems kind of dumb to let you adjust the individual timing and not record it? But on a good note, you can read the plugs and adjust accordingly.
     
    #12
    Blownalky, Dec 11, 2011
  13. Mike Canter

    Mike Canter Top Dragster
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    According to Racepak the recorded timing data off the Power Grid 7730 is only the mapped data that is being sent to the coil. This is normally correct and the engine timing should change with it. Not sure what would cause the actual ignition timing to be different than what is sent to the coil.
     
    #13
    Mike Canter, Dec 12, 2011
  14. JustinatAce

    JustinatAce Member

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    You get a nice flat, perfect looking map on your graph this way.. when actual/observed timing is recorded, it's kind of jittery and scary looking, even with a crank trigger. It's usually within a few tenths of a degree of what you told it to be. Even when you soften up the sensitivity in Racepak, it's rarely still a perfectly straight line.

    But for this argument's sake, say you've got 35 in the mag/trigger, you can tell the power grid, or any other controller for that matter, that base timing is set at 30, it doesn't know any differently. All your reference numbers on the map going to the VNet would be based off that 30 degrees and not the actual 35.
     
    #14
    JustinatAce, Dec 12, 2011
  15. Mike Canter

    Mike Canter Top Dragster
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    Hi Justin. I agree that it is easier to read from the Power Grid because it is a lot smoother. It is easier to see the changes in timing as the car goes down the track in reference to the driveshaft RPM, gear changes and things like that. The old way rough recording from the pickup from the crank trigger wheel is really hard to read. I am sure some diehards will say that it is no good unless it it from that front pickup but I much prefer the smoother easier to read one.
     
    #15
    Mike Canter, Dec 12, 2011

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