timing retard for nitrous .
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.
