timing retard for nitrous .

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jimjimjimmy

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i have a msd 6al with the msd billet distributor with no VA and want to run a timing retard , and was looking at the msd 8987 but it says to lock out your timing which i do not want to do. can i run it with my mech advance if not is there another setup i can use ?

MSD 8987 Start and Step Timing Control
 
It wont know if your locked out or not, but it may end up going into a critical area of spark timing where something bad could happen if it retards past where its supposed to go. a retard is always hardware based ie. you have to advance the locked out distributor where no box retard would be where it needs to be on a standard advance curve, you cannot add advance. The added advance that may be shown on the controller is not a true advance, its just less delay from the box itself.
 
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i have a msd 6al with the msd billet distributor with no VA and want to run a timing retard , and was looking at the msd 8987 but it says to lock out your timing which i do not want to do. can i run it with my mech advance if not is there another setup i can use ?

MSD 8987 Start and Step Timing Control


This is an example of when it’s ok to lock out a distributor. It’s best to be able to control the curve through the box if you can.

OTOH, if you set up the curve correctly you can leave the curve in it and run the boost retard.

For what you are doing I think a better box would be a good investment...something that can control the timing curve after the mechanical advanced it all in. Something you can change the slope of the curve with.
 
Interested in an MSD 8982? Not sure if it does what you need it to do. built in start retard and the pill socket is for 1 nitrous retard triggered by nitrous solenoid..
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Interested in an MSD 8982? Not sure if it does what you need it to do. built in start retard and the pill socket is for 1 nitrous retard triggered by nitrous solenoid..
View attachment 1715635277


thanks for the offer still doing some research no doubt there is lots of hi tech stuff out to do this but i think it can be done with either one of these msd's . so i'm reading 28 degrees is around what i need for a 150 shot so im 35 d all in at 2800 rpm so the nos wont be activated until around 4000 so 7 d of retard should put me at 28d i very well could be wrong in my thinking , all angles of thought are welcome .
 
sounds right, a 7 pill is what you need for this or that. If your getting a pill setup, get a 10K variable resistance potentiometer and wire it into the pill socket. Every 1K of resistance is 1 degree of retard. A 10K would give you a rotary control of 1-10 degrees retard.
product-front.jpg
 
sounds right, a 7 pill is what you need for this or that. If your getting a pill setup, get a 10K variable resistance potentiometer and wire it into the pill socket. Every 1K of resistance is 1 degree of retard. A 10K would give you a rotary control of 1-10 degrees retard.
View attachment 1715636028


interesting i never seen one of these before thanks . i thought there would be more guys running a timing retard without being locked out that would give up how it works for them .
 
At what RPM and how many degrees does your current ignition box retard? It does retard all on its own. You really have to know that first. Once you know that you can then make an informed tuning decision.
 
At what RPM and how many degrees does your current ignition box retard? It does retard all on its own. You really have to know that first. Once you know that you can then make an informed tuning decision.

my current box is a msd 6al i will see if i can find any info on built in retard if i am understanding you right . i think i learned something from this post but i'm not quite sure what yet .
 
my current box is a msd 6al i will see if i can find any info on built in retard if i am understanding you right . i think i learned something from this post but i'm not quite sure what yet .


I’m not talking about built in retard. Do a Google search for “slew rates” and read that. Then you’ll know what I saying.

Every ignition box, and I mean EVERY box will retard at some RPM. I’ve tested a bunch of boxes, and surprisingly the best box I’ve found (amd I own it) is a 1980’s era Chrysler gold box.

It retards 1 degree at (going off my memory here) at 7000 RPM and hold that to past 10,000 RPM. That box is unreal. But it is limited in what you can do with it. Any timing retard, start retard and stuff like that has to be done with external boxes.

Most boxes retard by the time the curve is in...around 3000 and they will have varying amounts of retard and at varying RPM.

So the upshot of all of this is unless you set the total timing at the highest RPM at he engine will be run at, you have no idea of the actual total timing you have, because the box WILL retard.

That’s why I say to almost never lock out a distributor. They need a curve. And you can’t account for the timing retard (slew rate) unless you know when and how much your box and at why RPM it happens you are just guessing at your timing.

For what you are doing you can lock yours out (I wouldn’t do it myself but you can) but you still need to now the retard of your box so you can make logical tuning decisions.
 
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