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Thread: MSD Start Retard. How to get good use without kicking back

  1. #1
    Senior Member DYNO OPERATOR
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    MSD Start Retard. How to get good use without kicking back

    Very Important!

    You must adjust the rotor tip to #1 plug tower index to be perfectly in relationship to one another according to how you are using your box.
    All these problems I keep reading about you can not have if the # 1 plug tower is closest to the rotor tip when it is trying to fire # 1 spark plug. Electricical energy will flow through the path of least resistance.

    So even if the rotor is closer to #1 it can jump to a different cylinder that has no or low resistance to current flow. 30 deg from the #1 plug tower is too far and if you have much compression I can promise it will be a different cylinder with the piston on the way up that will fire. That is where the kick back comes from, when you are using the start retard and the rotor was already retarded by accident or on purpose You are firing a cylinder that should not get ignition first.

    If your distributor is locked out with zero advance and you don't have anything else giving an advance curve and the engine is run as an all motor engine all the time, You bring deg marks on harmonic dampener to the total ignition advance you run. That is where the rotor needs to be in align with # 1 Plug Tower in the distributor cap.

    You have an advance curve in either the distributor or in a box so the timing is getting advanced with rpm increases;

    Example if you have 20 deg of advance in dist or in box, you adjust Rotor to be 10 deg retarded by backing off till balancer is showing 10 deg retard from where it is supposed to be at full advancve. You are splitting the difference. Never use the MSD Start Retard if total retard will exceed 25 degrees for starting.

    If dist is locked in and you are using nitrous, blower, turbo etc, requiring a running retard at launch or down track. Set and adjust rotor to be in index with balancer at 1/2 of the total retard you need maximum. SO for example if your full nitrous or blower hit requires a 15 deg retard, back off on balancer by 7 1/2 deg retard. So if normal timing is 0 deg and you pull out 15 deg total, set your rotor index to be 22 1/2 deg . IN that example this engine can benefit from 15 to 20 deg start retard but no more. 25 deg start retard is too much. That is why we had originally chips of different rates of retard available. You could retard from 2 deg up to 25 deg as you needed it. I am not certain if you can adjust the amount of degrees in the start retard with the new boxes. I do know that if you have rotor indexed perfect at full retard, it will be really tough on starter to start it. You need to split the difference.

    Is it Ok to use the retard that is built in to the Digital 7 box.
    Of course it is ok to use. Do all of you think MSD would intentionally put something into the ignition systems to cause you problems like broken flywheels, startrs etc?

    All of this was thorougly tested with correct ignition systems in two different cars with both having near 17.00 -1 compression before it was ever released to the public. I was the test bed for the first protypes and the original development, being the whole thing was my idea in the first place. After we felt it was ready to be sold, at my request Warren Johnson was included in the testing of the 2nd prototype of this and he liked it. Both his model and mine looked sligtly different than the ones sold to the public but were the same in function.

    Of course all of the early versions were analog with manual switching, and all the newer versions have a lot of automatic features and are all high speed oversampling digital resulting from Engineer Steve Masters (Father of all MSD Digital Boxes) taking our old antiquated slow analog technology and incorporting high speed Digital tech.

    All of the features of it are ok to use. I do like this regular Digital 7 box that is adjusted with the little rotary adjusters on the end of it (7520) or the programmable (7530 - 7531). What the retard is really, is an adjustable Start-Run Retard function that is contained within. The starting retard is very helpful for engines running locked out distributors with high compression, as they are trying to do the initial start while at full timing advance.

    In the past this resulted in either a very slow rotating engine and mucho load on the starting electrical circuits, or by just spinning the engine and flipping the switch, which usually did work ok unless the initial firing cylinder had too much fuel in it and then KABOOM. Intakes were blown off, Carbs were blown off and worse has happened just because of starting the car by spinning engine and flipping switch to on.

    In the early prototypes of the original Start-Run Retard we tried several different rates of retard by using the already existing Resistor Plug in Modules, called Chips. I discovered that when we tried to retard beyond 25 degrees to 30 and 35 degree retards, that there was a problem of the wrong cylinder fireing instead of the # 1 cylinder. So by trial and by error on my part we determined that we could retard the ignition to as much as 25 degrees with no failures. The Initial MSD Start-Run Retard came with chips to allow 20 degrees of retard, but the 25 deg chip was available for those requesting for more. This beginning concept was tested by using an engine with 16.85 - 1 compression ratio.

    On the opposite side of the little Control Panel we wired a retard to be available for use when engine was running at any desired rpm that was activated by a customer supplied switch, in the car. That retard was designed initially to be used for two different and unique purposes, and also did use a plug in resistor called a Retard Chip.

    That retard chip allowed an engine to be run with an intentional too much advance during the initial launch which actually gave it more power in the lower rpm ranges, because race tuners could tune the launch to be on the verge of pre-ignition, which in reality in the lower gears was not harmful and did give more cylinder pressures as the piston was leaving TDC on the power stroke. As the car got into the higher gears where the engine was under hard load, the driver could just by activating a switch (user, supplied and installed) to bring the engine ignition back to where they felt it to be a safe limit and where the engine was comfortable as it was in the higher geared rpm ranges where there was no additional multiplication of forces like in the low gear while launching.
    The bottom line was better ET and a harder launch without engine damage.

    The High Gear Retard function also could serve as a sort of Traction Control device, maunually operated, when encountering a slick track or bad track conditions. For that let us say that you are sitting in the lanes and almost ready to run. Opps, something happen in the lane you are getting in and you have no time to retune anything. You quickly make a desicion to use the retard chip that is in place or if you have been thoughtful in advance, you had a few retard chips within your reach so quickly swap them for more or less retard (BEFORE Launch) than you had in. You launch with the 3 position toggle switch in the full retard position, which will pull bottom end launch power out of the car. As quick as you get traction, you flip switch to the middle and leave it there until you hit high gear and again move switch to the right to get your high gear retard effect which should bring the engine timing back to where it is comfortable. WE initially had a little small panel with a Resistor Chip on each side, with a 3 position toggle switch in the middle. The switch was a spring loaded momentary switch when pushed to the left for a start retard. When engine started you released it to the center and neutral position. If you wanted to use the High gear retard you moved the switch into a locked position to the right and it stayed there unless you flipped it back to the center to de-activate all retards. Different drivers used different styles of switches in their cars. I had one that I could hit when I shifted high gear. Others used toggle switches.

    +========================================

    Now that I have told you how to invent the wheel, when all you wanted to know was if you could drive the car (Joke). I will tell you how all I just told is relavent to you now.

    Now you have contained in that little Digital Ignition Module all or many of the features I just named that have been made to be simplier and are also now Digital, which makes them act and react much much quicker and better than anything we originally used. Now you can set your Starting Retard to be active or to be non-active, by your selection, and instead of the driver having to release the momentary loaded 3 position, toggle switch, The box senses when engine RPM is sufficient to go back to initial advance settings. You can now activate a two step and a Start-Run Retard in the same box by only flipping a switch or two in your car that you supply. Or in the programmable boxes you can even set a starting launch retard which can be left out or ramped back in as you want.

    You can use the starting retard feature to make it easier for a high compression engine to spin for starting. You can use the adjustable for rpm now, second stage of retard for any purpose you wish. Read how we used the original design to aid traction, and at the same time regained full ignition as soon as we had traction. You can too. That wire going to the toggle switch, activates it when it is set correctly in the adjusters on the end of the Digital Box. You can use the retard for retarding the engine for N2o, for blower boost or for turbo boost, or use it for the examples I gave in my writings.

    A couple of words of suggestion for all Digital Box users of any brand. Buy a Spike Protector and wire it in line with your Battery fed Positive and Ground. That helps protect your bax from failures that can damage it. All Computers and Digital controls are far more sensitive to Spikes than the former slower acting analog components.

    Also in all applications using the Digital 7 box try to install it where it will have fresh air flowing over the heat sinks on the outside case.

    Sorry to have been so long winded, but maybe I have helped some of you some.

    Ed
    " Let all things that hath breath, praise the Lord. Praise Ye the Lord" Psalms 150 vs 6.

  2. #2
    Senior Member RACING JUNKIE
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    thanks Ed...another great post.

  3. #3
    Senior Member MASTER BUILDER
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    kickback

    Thanks Ed, You did it again. Im 1 that has been fighting kickbacks and fires too. We cut the hole in the cap and appears to firing straight with the terminal on the cap. Did this many times with and without looking in with the timing light. So the question is just keep rotating the crank trigger dist and it should stop the kick back, no matter where the light shows it to be. Also this will place it in the best running position? Seems there are a lot of us that just dont get it. What You say is correct, but many still have the same issues. Retard is unhooked, at least it starts. :shock:

  4. #4
    Junior Member SHOW GUEST
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    Re: kickback

    Quote Originally Posted by topcat572
    Thanks Ed, You did it again. Im 1 that has been fighting kickbacks and fires too. We cut the hole in the cap and appears to firing straight with the terminal on the cap. Did this many times with and without looking in with the timing light. So the question is just keep rotating the crank trigger dist and it should stop the kick back, no matter where the light shows it to be. Also this will place it in the best running position? Seems there are a lot of us that just dont get it. What You say is correct, but many still have the same issues. Retard is unhooked, at least it starts. :shock:
    MSD CAP-A-DAPT WITH ADJUSTABLE ROTOR

  5. #5
    Senior Member DYNO OPERATOR
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    You can get a starting kick back from your crank trigger if the gap is not close to .060

    Ed
    " Let all things that hath breath, praise the Lord. Praise Ye the Lord" Psalms 150 vs 6.

  6. #6
    Senior Member MASTER BUILDER
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    kickback

    The gap is at .050. The 468 didnt do this, only the 572. I even put a new trigger set up, as the one on there was a few yrs old. No difference. ops:

  7. #7
    Senior Member DYNO OPERATOR
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    GREAT, GREAT POSTS Ed Thanks from all of us for everything !!!!!!!!!! David.


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