Engine ignition timing

[racydave]

When I put in the distributor-less system in my Spider, I figgured the seat of my pants was good enough to map a good program for the ignition. After many attempts getting close, then guessing wrong, it was time for some improved tecnology. Yesterday I picked up a used lap-top. The system maps according to engine load, and rpm's. This allows a 10 by 10 grid. 100 choices. Engine load is adjusted by measuring the vaccum in kilapaskals( sp?) kpa. With the lap-top installed, I now can make the adjustments while driving under real conditions. Its still kinda seat of the pants, but I should be able to come up with a very good ignition program. Needless to say, im really exited to get this accomplished. Now if I can get my assistant to free up some time to help out, we can get her dialed in! I have also been messin with carb jetting, and plug gapping. Ill be glad to get past all this so I can start working on my bumpers, and finishing the interrior!

[rlux4]

On last year's trip when Ace and I, with our wives, joined the BARF group as they headed north (the long way) from BFI, Ken Haven had his laptop out as he checked his over 300 HP Lancia's mapping. I was curious how this works, but never got around to asking him. How do you plug into the system, and what is done to get the tuning where you want it, Dave? You've probably said already, but what brand of ignition system do you have in your car now?
Ron

[racydave]

This is the MegaJolt Jr. set-up. It deals with the ign side only as I run a carb. The MegaSquirt deals with the fuel injection. Im challenged enough with the ign side, doin the fuel injection and maping is some pretty tall stuff. Basically to start with, I ran a generic program to get it running. Then I adjusted the paramiters as to base timing for eng start up, timing at idle, and total advance. The real trick is to create the proper curve to tune her in. Its easy to guess in the wrong directions, especially at lower rpm's and under a load which is represented by low engine vaccum, or higher kps. At speed, the ignition events occur very rapidly, and the chain of events on a standard distributor rely on the timing belt, and mechanical play in the engine and distributor. The megajolt is based on a ford edis system from cars built in the early 90's. It uses a reluctor wheel built into the crank pulley, with a pick up sensor at the wheel. This provides a more accurate ignition event without all the play and inaccuracy of the conventional dizzy set-up. Its just a step into the 90's, as most modern cars are run similarly. Of course this all might be a little overkill to alot of people, especially as its still carburated. The stock dist I had to work with was totally inept as to base and total ignition timing, so my choices were to have the dist re-curved, or go electronic.

[So Cal Mark]

it's not overkill at all; modern engines produce the huge hp numbers through engine management.

[ga.spyder]

For a ticket to the Brickyard 400,I would have freed up some time and been the assistant That stuff is way over my head,but its gonna be an awesome car when complete!!
Craig

[racydave]

Well, after a long bout getting the used lap-top to interface with my control module, we finally kicked some ass! I had to re-write the program I created as some values were imputed inversly. In other words, I screwed up. But having the real time program running in front of you is the only way to understand and adjust this system. My tuning buddie and I took her out tonite and customized the ignition to a sweet result. It runs far better than it ever has. The tail pipe is cleaning up, and the sound in general is vastly improved. Im sure the efficientcy has jumped, and maybe now, I'll check my gas milage. This part of the project has been on-going for 2 and a half years. The 36 ADL, headers, and ignition system together and finally tuned! I recently have re-jetted the carb to lean it out a tad. Also new NGKs and wires too. I hope you dont take me wrong here. Im just so exited that its finally come all together! What next, the block and head are stock, as well as the cam(s)?

[rlux4]

Imputed inversely?!?
No way I'm going near a mod like yours. Waaay too technical for my little pea brain.
I'll wait until I get a ride in yours.
Ron