Jacobs Omni Magnum or MSD Stacker?
 

This is my first post after scanning the board for several months. This forum is a wonderful resource, especially for a newby like me. I own a 1973 911E Targa. I have the original 2.4, MFI and CD ignition. I've gotten the car running quite good and have no complaints (except that the MFI is running a little rich, not to the point of fouling the plugs).

My question is threefold and in all my searching I haven't seen it specifically addressed. First, is there any benefit to be gained by attaching an ignition control unit like the Jacobs Omni Magnum (http://www.off-road.com/jeep/reviews/jacobsomni.htm) or MSD Stacker (http://www.msdignition.com/n2000.htm)? For example, easier starts, better idling, better gas milage, more power like the ads suggest? I like the idea of these two units because they would leave my existing (and operational) CD unit intact. Secondly, if there is indeed some benefit to be gained, has anyone tried either of these units? Is one better than another or should I scrap the existing unit completely and go with the MSD 6? Any comments or recommendations would be appreciated. Finally, any thoughts on replacing the points with an Alison optical trigger or Pertronics unit would also be appreciated. I don't mind gapping the points and setting the dwell but it sure would be easier if I could get the same (or better) performance and didn't have to mess with points -- more time to drive!!

Thanks in advance for your help :)

David Clark
1973 911E Targa

David, many of the guys here have switched to the MSD 6A and seem to love it. But I suspect most of them did so only after the original CD box failed. There have been some pretty extensive threads here on both the MSD and the pertronics gadget. You might do a search..MSD experiences seem generally favorable, pertronics is a mixed bag...

Thanks for the reply. I used an MSD 6A on my old 1971 SAAB Sonett II (1.7L V4) and had really good results so I am a believer in MSD products. What I'm really interested in knowing is if anyone has any experience with the Jacobs or MSD or other "add on" units on an early Porsche 911. Not the replacement units, but the kind the work together with the existing CD ignition. As you can imagine, I really don't want to rip out a working stock CD unit. Do these "add on" units help or will I just be wasting my money? Both companies promise substantial improvements but I am still skeptical. What do you all think?

I've never tried the add on products, so I dunno. My thinking is as long as it isn't broken. as long as I'm running fine, I'm not going to screw with the stock set-up. Guess I'm an old curmudgeon, but if it's worked well for 31 years, why try to "improve" things?

I'm not sure about them either. I'd like to know the science behind them as well. I would think that adjusting the MFI would much more for the engine than the aftermarket ignition stuff.

BTW I am thinking of switching to the pertronics ignitor as well to eliminate the dwell and points gap adjustment.

David, you've got an email as well.

maybe search their sites.. and the multiple sparks help keep MFI and carb plugs clean.............Ron