Keep MSD or use coil packs when going EFi?
 

I'm debating going EFi and will use SDS if I do. I have recently installed an MSD unit and could use an SDS EM-5E that will control it but still use the dizzy for spark distribution. It will be crank fired versus distributor mag sensor however with timing controlled by the ECU not the MSD.

Alternatively, for not too much more, could go EM5-F which completely removes the dizzy for coil packs. Wanted to sound you out on if its worth keeping the MSD from a performance standpoint or should I just go all the way with the SDS and coil packs, recoup some cost on the MSD by selling it and go with coil packs?

I would think it would have to do more with if your current setup is CDI. If you go with coil packs and you use them as a wasted spark setup, you will be downgrading in spark energy. If the coil pack system is used as a CDI system, then you will have a buttload of spark energy at the plug. ( I am assuming that your current MSD system is CDI, and if it is, I dont think you would see much benefit.... Other than the easy ability to go twin plug with the coil packs (think alot cheaper than a custom twin plug dizzy)

Cheers.
The MSD is a CDI but the SDS coil packs are not so was biased towards keeping the dizzy and CDI, but torn about the 'clean up' benefits of canning the dizzy. Its mostly street so probably would not matter much either way.

I might sound like a broken record about this but if you go to the latest technology which is coil on plugs then you also can ditch the spark plug wires.

would love to go coil on plug but the SDS package comes with wasted spark coil packs only. Would have to go with an alternative ECU which I don't want to do if I can help it.

I made my EFI conversion using SDS EM4-F as some others too. The SDS is a bulletproof solid system which is in my eyes best for DIY people like me. And support is very good. Ask them for the detailed advance between E and F systems, if not answered on the SDS website.

I think Ignition control and mapping will be a lot easier when all programming will be done in the SDS ECU, than have an external control unit...

Here you can find my conversion:

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/580883-another-efi-conversion.html

Here is another from JIM2 (the reason I choose SDS):

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/296579-930-efi-conversion-process.html

thanks.
I stand corrected, you can use coil on plug with SDS, as you can just buy the coil driver version with no coils.

Just to clarify, with the 5E that drives and MSD, the SDS still does all the timing control as it uses crank magnets for triggers instead of the dizzy mag sensor, but will still use the dizzy to get the spark to the right cylinder. The SDS will tell the MSD when to fire. Timing in not effected by where the dizzy is, only phasing of the rotor.

Here you'll find some info from SDS about the different ignition types:

Tech Page

What's the simplest ignition system upgrade one could do to the stock system?
Sorry for the hijack
c

*clean and inspect for faults and wear
1- ditch the points
2- msd cdi

Does anyone know offhand if I use a multi-channel CDI like an M&W six channel, and gang for wasted spark, can I connect it directly to the SDS or will I need the coil driver box? Have asked them but though someone here might be running coil on plug with CDI in wasted spark.

I would follow the recommendation by SDS, they have plenty of experience and everyone I talked to was very happy with their system

...and whatdid SDS answer about six channel CDI?

Still waiting for some feedback from them, wanted to know if the SDS can drive the M&W directly or if I need a coil driver box. Will let ya'll know.