I agree the wasted spark coils are by far the cheapest way to go. I already had my billet dizzy so I stayed with it. Possibly I will end up going to COP's at a later date. If you have nothing to start and need to decide what to do then I'd go with wasted spark use a hall effect crank trigger and a Ford hall effect cam sensor along with the adapter to mount it to the cam tower. This would definetly the cheapest. If you want to step it up a notch COP's which would not require sparkplug wires. But you would need valve covers to mount the COP's. Hargett Percision Products makes billet valve covers that mounts Ford COP's.

Hi,
Very sweet, what Program did you use to diagram this out with?

Wasted spark ain't a bad thing. I guess you can use the distributor and have full control over ignition timing, ehhh? I can tell you that I lost a cam sensor and it caused my car to go full lean everytime we hit 4000 RPM. It was hell identifying the problem. The sensor didn't quit, it just quit working evertime it hit 4000 RPM. It may have been RFI/EMI noise. It had been fine during the first 60 or so hours of tuning and running. I now am in "Batch Fire" mode and am not certain I am going to screw with it again. I gotta a feeling this may have happened to DonE possibly. Personally I wouldn't be looking for a distrbutor though.

My problem was me. I had a poorly crimped 12v supply and it finally failed. Fortunately, the LINK tells me which trigger has an error so I was able to tell what was going on immediately.

For what its worth, if I had to do it all again, I probably would have saved a bit more money and gone with some sort of CDI ignition. I currently use wasted spark and it works well, but I think I could get better drivability and torque with CDI. To improve idle and high RPM drivability, I reduced the gap on my plugs from .028 to .023. It smoothed my idle out but I haven't tried the high rpm yet. It's a good thing I have dual plug with this ignition system.

Nathan,
If you haven't found it yet, here's a pretty good thread on a dual plugged MegaSquirt II installation with some pictures on sensor installation, some sample fuel and ignition maps and lots of Q&A from folks on the forum. http://forums.pelicanparts.com/porsche-911-technical-forum/279322-megasquirt-setup-930-dual-plug-edis.html

Noah, great work on the illustration - that will help a lot of folks.

I've been running MSII for a couple of years and have been very happy with it. Good luck!

Yeah, I agree! That was a pretty impressive post, from Noah!!! Being that I'm running so well on my modified CIS system, I'm a long way off from an EFI conversion, but stranger things have happened...

Thanks Guys!

I have to admit, I forgot to search the 911 forum...

Belive it or not, MSpaint. Paint is great for doing simple little diagrams for your own notes. I can make them with cad or ProE but paint does a great job for this and it's easy to use.

Thanks. Just so everyone knows Mike (mppickett) was the first to post the EDIS twin plug diagram, I just incorporated it into the complete diagram I previously posted.

The knock sensing module I am still working with, I think it should be fine but I might need to add a fuse on the +12V power line off the main relay. Also, there is a chance that I will have to add some sort of signal conditioner to dampen out noise that is from normal operations. I see no reason why we can not have knock sensing on our engines.

Thanks, I try to be of some help. I guess it is in return for some of the overly inquisitive post I make from time to time.

+1, nice work Noah.

Not if you're cheap and use the Burn Bros distributor conversion that takes the E-type cap... :)

http://forums.pelicanparts.com/porsche-911-technical-forum/173248-twin-plug-goodness-look-what-i-made-weekend.html