I have been told numerous times that for my race car I need to lockout all the advance in my distributor because I am running nitrous.
Now the question is, a computer controlled distributor, when it is not hooked to the computer, will it still work?
Secondly, if it will still throw fire like normal, isn't this a very simple way to "lockout" all advance?

Just thinking of getting the race car in race shape and thought of this

Thanks for the replies in advanced

 

U can change the pick up coil to a older HEI style and run it.

 

I don't really know the answer to this, but I know you could put in a standard HEI dist and fool around with it to either lock or limit the advance. Might be able to find out what the connections do at the dist, and just use some of them. I would imagine that the computer wouldn't be too happy about not getting a signal from the dist. I would suggest using an adjustable timing light to see if you can tell how the computer puts timing into it, but that may not be very accurate since I'm not sure how they are setup to put timing in or pull it out.

 

See the computer is LONG LONG gone in the race car. I was just toying with the idea is all.
So put a regular pickup in it and away we go, right?

Sounds like a good use for an old dist to me

 

you can even put a vacuum advance on a computer controled ditributor by cutting a noch in the rear of the hosing so the cap will fit 180 around. Un bolt the advance cover and replace it with a vacuum advance.

 

Not sure why you'd bother with vacuum advance when you are trying to lock it in.

The computer module has some built in "limp home" advance. It isn't much, and you could set max advance with higher RPMs, just like you do with centrifugal advance.

But, the standard module in the computer distributor sounds like the best idea to me. No advance of any kind, just set the timing and go. I'd have to double-check the pick-up coil connections - 7-pin vs. 4-pin - but it would probably work.

Are you using any ignition box? If so, it will even eliminate the module.

This is a great use for computer distributors that I had never even thought of before. What a Board!

 

Daggon,
so if I use this MSD i have had sitting here for over a year I dont need the pickup module at all?
I picked the box up second hand and have not even had a chance to look at the installation on it at all.

Lets explore the use of the MSD box a little more shall we?

 

If he wants to drive it on the street I don't know he'd run without vac advance. Very few setups benefit from true locked out timing. Your lean cruise and decel is going to want about 10-15 more degrees than WOT and idle.

If it's a drag only car than yeah, I guess true locked out is fine. But then again, he'll probably want some crank retard.

-- Joe

 

yeah the truck is a true drag only racer, my 82Z on the other hand is for cruising.
Crank retard would be good but I think I can get by with out it. We shall see and I will post up here how it all works out

 

Which MSD box do you have?

Back to first principles, locked out timing and nitrous do not have to go together. The key with nitrous is to limit the advance when the nitrous is on. The MSD Digital 6 has timing retard above 2000 RPMs that is triggered with the nitrous (or whatever reason you have for changing the timing during the run). It also has built-in start retard.

Locked out advance does tend to be a little more accurate.

 

Your MSD will still need the pick up in the dist. to fire it. No module will be needed. To clarify what I posted earler is that a computer controled dist. can be changed over to a vaccum advance if you want to. For a street - strip car a 4pin GM HEI is hard to beat.