I thought this might be the way to get the curve, initial and total numbers wanted without changing springs & weights a bunch of times or removing the shaft to weld and file the slots multiple times. I downloaded the software but it looked like the process is way beyond my computer understanding. Anyone try one of these?
Yes, I'm running an MSD 6530 programmable 6AL ignition. The computer part is so simple at first it is hard to understand, at least it was for me. Seemed like there should have been more to it. First, electronically advancing the ignition isn't possible so the distributor is installed at the desired full advance. The controller then retards the spark based on RPM. That is the run retard program.
A couple things to consider. Unless you are running a large cam with relatively low compression or looking to pull some advance out at a boost pressure then controller might not be the bast choice. Something else to consider is giving up the vacuum advance. At low load, part throttle cruse, vacuum advance plus initial and centrifugal generally in more advance than total at WOT. Better gas mileage is the result.
Something else to consider with the distributor locked out and the controller running the timing map is the need to use an adjustable rotor so at low and high advance settings cross firing in the distributor cap doesn't happen. I experienced starter kickback before I got mine straightened out at least its fixed so far. (Fingers crossed.)
Finally, controller is limited to a 30 degree differential between high and low advance settings. I'm running s 461 BBC, 10:1 CR and Comp Cams 292 cam. (244 duration @.050"; 544" lift;,110 CL) My distributor is installed at 38 degrees advanced. With the controller I retard timing to 18 degrees from 0-400 rpm then ramp up to 26 degrees at 1000 rpm. 38 degrees is all in by 2800 rpm. (Same as stall speed) took me a lot of messing around but car runs strong.
I'm 56, been street rodding my whole life and I'm decidedly old school. My first time using anything like this. If I can figure it out anyone can. If the application is right the programmable controller is trick stuff but research what you're getting into. I can supply more details if interested.
Dennis, Thank you for that reply, I will most likely be asking you some specific questions later, for now, this is what i'm working on. I have a 464ci 428, zero decked, 10.5:1 static compression ratio, stump puller roller camshaft, aluminium heads, HEI. I got my best power and torque at 28 degrees on the engine dyno. As I am on the verge of detonation I don't want to go above the 28 degree mark. I also praise the virtues of vacuum advance and would definitely use it if I was not worried about detonation, I have mine blocked off. I don't need the burn-out limit or the launch limit or the step limit of the ignition box, just a curve that will give me 16-18 degrees initial and 28 degrees total at 3,200 rpm and perhaps a high rev limit at about 6,500 rpm. I'm 10 years older than you and am so old school my phone is attached to the wall with a curly cord connecting the hand set and a rotary dial on the front. I use a slide rule not a calculator. So when I read the instructions on setting up the ignition box via a computer it soared well over my head. I don't know how I would connect this antique desk top to my car or can one supply the box with 12 volts and program it on the bench? Maybe if I had a 12 year old grand child he/she could program one for me but alas, I am 12 year oldless.
Losing the module out of the HEI wouldn't upset me as they have a tendency to fail, but I don't know if they would fail any more that an ignition box would. I trust mechanical things more than I do electronic but would be willing to try the ignition box if it meant not having to weld up another distributor shaft.
A couple of the guys here have just natal led the FITech System on their cars. They will do everything you want and more via a handheld touchscreen for about $2K. It'll control two electric fans and some other crap too. You may be in the same shape as me though if your setup is compatible or not.
Sorry for the delayed response its been a hectic travel week for work.
I've enclosed a link to MSD's web site for one of their adjustable rotors. In the technical tab there are the typical MSD installation instructions plus a technical bulletin explaining rotor phasing better than I ever could. See the section titled Phasing and Electronic Timing Controls. If you dig around on FI Tech's web site and find their installation instructions, they also have a good explanation of rotor phasing when controlling the advance curve with their system.
I actually use my old computer (really old...) to communicate with the ignition box. It's the only machine I have left with a serial port. They make a USB to serial cable, I just never bought one.
Ha! My curly corded wall hanger has touch tone push buttons in the hand set! Hmmm, don't think it makes me modern by any stretch. I'd be happy to discuss over our land lines if you get to that point. Just PM me and we'll get together.
While I've done some research with FI Tech systems, I'm not sure how flexible they are with big cams. Long duration, tight lobe centerline camshafts (<112 degree centerline) generally reek havoc with off shelf EFI systems at idle. I might switch to one of their systems if I could get it to behave with my big cam without a lot of grief. I sure like the idea, but will not give up my big cam after working to tune the thing with the Holley/MSD combination. If you have big cam/FI Tech experience please share.
I don't have any personal experience to share with an EFI. Most everything I've read says that they don't work well with big cams unless you get one that can be programmed to allow for it. I'm not sure, I've had a conversation with one guy that swears he has used one of the self learning units with a bigger cam than I'm running but the other 20 guys say it doesn't work. I suppose the only way to know for sure is to try it for myself. Don't really want to blow the grand on the off chance though.