MSD grid /step retards& Ekectrimotion timer

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by Jason Green, Dec 28, 2018.

  1. Jason Green

    Jason Green Member

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    I'm getting ready to start wiring my car and as I was mapping out my electrical panels I came up with a question for you guys. I have a grid, and I also have a 15ch Leahy box. My plan is to use the Leahy box for fuel system and shock timer .I'll have multiple channels left . So my first question is this; when wiring up the fuel lean outs, can I have multiple channels operating a given solenoid? IE, if I have 3 lean outs, all different jets, can I turn them on and off with one channel and then back on back off with another? Or is this even necessary? I'm really not sure how much fuel manipulation is needed, but I don't want to get in to re wiring or adding stuff later . My second question is; would it be a waste of time to wire the 5 step retards in the grid to 5 remaining channels in the Leahy box? Or do you guys that are running grids just use the launch curve to make all timing adjustments? Again, I'm not sure how much manipulation is needed
    My combo is a blown hemi pro mod
     
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  2. rb0804

    rb0804 Member

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    Things are pretty flexible these days and it depends on how creative you get with the wiring. Why not just add the 3 stage timer to the grid via the can-bus? You can plug in two 3 stage timers and have 6 stages of triggering for what ever you like. 3 pole leanout, shocks dump, converter pressure or lockup up trigger, etc.
     
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  3. Jason Green

    Jason Green Member

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    I could, but I already have the electrimotion timer and I like the idea of being able to make changes to the fuel system timers without needing a laptop
     
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  4. Mike Canter

    Mike Canter Top Dragster
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    Let’s see if I understand correctly. On the Leahy timer it is one timer channel to one solenoid which is one turn on and one turn off per channel/solenoid. As far as the Grid Step Retards here are some ideas. You can wire up one retard to 12 volts so it is always on then with 3-5 degrees (whatever you want) set your timing to what ever timing you normally have at idle. So in the future if you check the timing before a run and it is off then adjust it by changing the step retard and not by moving the crank sensor or mag. You can wire up another two retards to two switches in easy reach. Set one retard at one degree retard and the other at two degrees. Now if you are getting ready to run and the track is slicker than you planned you can turn on one or two switches in any combination to pull out timing for the run
     
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  5. Jason Green

    Jason Green Member

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    I think we're on a similar page Mike, or at least reading the same book lol .I was thinking about hooking all 5 steps up to individual timer channels, with say .5-.75 degrees in each and then they can be enabled in the staging lanes as needed to reduce my whole timing curve by as much as I think I need
     
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  6. rb0804

    rb0804 Member

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    Will 1-5 step retard work all the time? What I mean is if it’s there idling and I flip the switch to engage step 1, it immediately starts retarding Timing to the preset values in step 1? I wasn’t sure if there was an inhibit where say the transbrake would have to be cycled before the step retard would work.

    I like the Leahy command module for the reason stated, you can make changes in the lanes quickly without a laptop or issues. It does pretty well everything now two step, rev limiter, fuel timers, ignition retard, boost retard, safety box, ability to pull timing on two step. You can even add on an autoshifter if need be and your rules allow it.


    The grid is neat also. I see what your trying to do and think that leaves a lot open to user error, but that’s just me. If I’m unsure of something I will leave the lap top plugged in and will make any final adjustments before we roll into the water box and then just unplug the cable and take the laptop with me. That doesn’t happen often as I have a good idea of where the track is going to be and how the weathers been tracking before we even go to the staging lanes, so the tune up is pretty well set. I watch how and when they prep the track and will make several trips up there through out the day to chart any changes. That way I have a good prediction as to what we are gonna see for our next run. If someone oils the whole lane in front of you, that may be a game changer, are they going to get it all? Is it going to be over preppped? Is the surface going to cool down a bunch because now the sun is setting or it put us deeper into the night and closer to the dew point?
     
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  7. Jason Green

    Jason Green Member

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    Anytime you put voltage on the step retards they'll turn on
     
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  8. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    To answer a few questions:

    Yes you can turn one leanout solenoid off and on with multiple channels.

    Most of the cars you may see using a bunch of leanouts are just using smaller jets to take smaller steps. If you are new to tuning a car like this, keep it simple to start. Maybe wire them to a terminal strip for future expansion, it wouldn't be that hard to make a run from the Leahy harness to do this without having to completely redo everything.

    I'm going to stick with the 'simple' theme on the step retards. Pick a timing curve in the lanes and stick with it. I've preached this - come up with some parameters before you leave the pit on what changes you are going to make for certain conditions. Like playing pool "Think long, think wrong." I would be scared of showing up to a race with a step retard activated and forgetting about it and moving the trigger to make the timing 'right.' Also taking timing out for the whole run isn't as good as fixing whatever problem spot you are worried about. Richening the main can achieve the same result as pulling timing out the whole way.
     
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  9. Mike Canter

    Mike Canter Top Dragster
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    I am only saying to use the toggle switches if needed right at the last minute. I agree use the laptop and not the toggle switches for normal operation. The one Step Retard on all the time to adjust the timing works well. It sure beats adjusting the crank trigger all the time. You hard wire it so you can’t screw up. If you don’t want to use it you zero it out.
     
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  10. Jason Green

    Jason Green Member

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    This is all good info guys thanks! One other question though...how are you keeping the grid from running the timing curve Everytime the trans brake button is pushed, ie shifting from fwd to reverse with a converter drive setup? I was thinking about putting the blue two step wire on a toggle so it's interupted until the switch is put in "race" or something like that. Any suggestions?
     
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  11. rb0804

    rb0804 Member

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    I just let it ride because it resets after the button is depressed again. What would be handy is a heavy duty switch at the gear selector that pulls a decent amount of timing at idle to aid in dropping the idle a tad if needed to assist in the selection of forward or reverse.
     
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  12. Jason Green

    Jason Green Member

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    I know from messing with small tire stuff we drop a ton of timing out with a launch retard, enough that it makes the motor extremely hard to get to idle if it's left to run the launch curve every time you hit the transbrake button
     
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  13. Mike Canter

    Mike Canter Top Dragster
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    The other way is to have two Transbrake buttons. One straight to only the transbrake and one to the transbrake and Grid.
     
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  14. SpeedDemon

    SpeedDemon New Member

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    Thanks for that post Mike.
    This was my thoughts on how I was going to wire my car. One button on the fwd/rev and one on my hand brake. Sounded simple and logical to me.
    Once again, great questions with great answers and ideas.
     
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  15. Jason Green

    Jason Green Member

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    You would need a diode to keep the secondary button from energizing the two step on the primary side​
     
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  16. SpeedDemon

    SpeedDemon New Member

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    Exactly. Or as you mentioned, running an additional switch.
    I've done similar things on my bracket cars. Wired the line lock and brake to same button. Burn out, flip switch to engage brake/grid and line lock at the line. Works great.
    When I decided to have a push style hand brake, it only makes sense to have two buttons. Trying to shift fwd/rev big pain if only one button to operate brake. Two properly wired buttons was my best idea.
     
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  17. Jason Green

    Jason Green Member

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    You've got it
     
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  18. Mike Canter

    Mike Canter Top Dragster
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    I would never use a switch that you would have to remember to flip after burnout. Things happen and you can loose your train of thought and forget. That’s why pilots sometimes land wheels up. Use a diode, You need a 3 amp 50 volt diode. If you still have a Radio Shack around they are cheap. The diode acts as a one way gate for power to the Grid. The Grid does not draw any big amps on that blue wire. If you need help then email me. You can search Amazon or Google and find tons of 3 amp 50 volt diodes cheap.
     
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    Last edited: Jan 7, 2019
  19. Mike Canter

    Mike Canter Top Dragster
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    Thinking some more on it. The power handling of the diode would depend on what make trans brake setup you have. If it was a Lencodrive you normally use relay versus a Bruno without a relay. For safety you can go up to a 10 amp 50 volt diode or put two of them together in parallel
     
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    Last edited: Jan 7, 2019
  20. sammy christian

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    wouldn't hurt to use a modern delay box like a Mega-450 or similar to solve this and provide additional timers for other things like shocks, shifting, etc.
     
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