Thread: Programmable Ignition Timing

The vacuum reading comes from the existing vacuum advance hose. There is a port on the Black Box to plug this line into. Since you lock the mechanical and vacuum advance in your distributor its no longer needed for the vacuum advance module anyway. I am using full manifold vacuum, not ported.

Thanks for that Richard.

As previously posted (somewhere) I used to run manifold vac before going electronic.

Wouldn't idle properly with the new set up so went back to ported and it's fine.

Did the box makers say to use manifold vac?

DL

The instructions for the Black Box say to use full, not ported, vacuum. Since I got my 1988 Range Rover, about 1 1/2 years ago, I have run full vacuum with the electronic distributor and have had no trouble. It was ported when I got it, but changing it was one of the first things I did. As far as I know they only used ported to help emissions at idle.

Just wondering if anyone else is considering fitting one of these units?

Yes, I have been looking at this type of thing for a while. I am only running fuel and not LPG.
So I won't be able to simply copy your maps.
Have had interest from Lloyds eng. in UK but the cost of the unit they recommend/sell (123. ) is ridiculous when applying exchange rate and postage.

Have previously done mods on old style distributors, but it is a long and painful effort.

Hence, I've been following your progress with great interest. If I go ahead and purchase one, I would definitely be contacting you for tips etc.
Ron.

I have been running the Black Box now for a couple of weeks and have all the gremlins sorted. Previously to get good bottom end on LPG I had to give the distributor 18 degrees initial timing, but this gave far too much timing at high revs. To get good top end previously I had to set the distributor to around 6 degrees, but this gave poor bottom end on LPG. With the Black Box I have been able to set it at 18 degrees initial (it says 28 degrees because the vacuum advance adds 10 degrees at idle) which gives really good bottom end. I also set, through the MAP, the total timing to be 28 degrees which gives me good top end.
I think this is a far better option than getting a distributor re-mapped. The spark table I am using could still be refined on a dyno, you just need to change a few numbers. To me, well worth the money, even though it was a bit of a headache to get working.

MAP1.jpg

Originally Posted by Richard Kaye

I have been running the Black Box now for a couple of weeks and have all the gremlins sorted. Previously to get good bottom end on LPG I had to give the distributor 18 degrees initial timing, but this gave far too much timing at high revs. To get good top end previously I had to set the distributor to around 6 degrees, but this gave poor bottom end on LPG. With the Black Box I have been able to set it at 18 degrees initial (it says 28 degrees because the vacuum advance adds 10 degrees at idle) which gives really good bottom end. I also set, through the MAP, the total timing to be 28 degrees which gives me good top end.
I think this is a far better option than getting a distributor re-mapped. The spark table I am using could still be refined on a dyno, you just need to change a few numbers. To me, well worth the money, even though it was a bit of a headache to get working.

MAP1.jpg

A re-curved HEI distributor would have cost the best part of a grand.

Dual map would just require 2 black boxes and some minor wiring.

Your latest timing figures aren't too far away from the old 14+14+14 using ported vac.

Well done!

DL

Originally Posted by Richard Kaye

The instructions for the Black Box say to use full, not ported, vacuum. Since I got my 1988 Range Rover, about 1 1/2 years ago, I have run full vacuum with the electronic distributor and have had no trouble. It was ported when I got it, but changing it was one of the first things I did. As far as I know they only used ported to help emissions at idle.

Early in the piece when the holdens and fords introduced emission controls vacuum advance went from manifold to ported so timing became throttle position /speed (weights) based .

I would cut/bypass the emission crap and put the vacuum advance back to manifold (load /speed (weights) based) . Sometimes mucking around with different spring rates for the mechanical advance (my preference to filing /adding to the weights).

Strictly off road use of course....