Ignition System question

[FF33rod]

I'm doing lots of reading, following build threads and more planning as I wait for my kit from FFR.
I've found all sorts of tutorials and how-to videos and articles on all sorts of subjects. For ignition systems, I've seen various information on the major components and I've seen articles on how to convert your current ride over to CD ignitions, etc but have not found anything that says "if you're starting from scratch, here's the way to go". There's so many choices on distributor types (ready to run, etc) and ways to configure stuff (rev limit in EFI system vs ignition, timing advance in EFI vs distributor).
So I thought I'd run my current thinking by you good folks and see what those that are familiar with this stuff thinks....

My setup: 347 SBF that I'm building up from a short block and top end kit from TRE Performance - has a hydraulic roller cam. Expect to make about 450hp and similar torque. Holley EFI Sniper.
For ignition I was thinking MSD Pro Billiet Distributor 8598, Digital 6AL Ignition control 6425 and MSD Blaster SS Coil 8207. Do these choices make sense?

With this combination, there are still some configuration choices to make:
1. Rev limit - The 6AL can do this OR the Sniper can do it. Anyone know advantages of one vs the other? Since it's built into the Sniper I could use it and order the MDS 6A (without limit function) and save a few dollars.
2. Timing advance - this can be done mechanically in the MSD distributor or electronically by the Sniper. Holley actually suggests you start initially using the distributor and then once things are running well, try to change over. Has anyone made the change to using the Sniper for the timing advance and did you see any difference? I guess I'm wondering why one would bother.

Thanks
Steve

[FF33rod]

no one with any comments or thoughts?

[NAZ]

Perhaps you've asked about a combination that's not very popular with the folks on this forum. I suspect if you separated the two systems and asked for feedback you'd get a preponderance of negative comments about the MSD 6AL as I've read comments here before indicating that this system is not popular with many here.

I run the same basic ignition system you described above but with a carb on a race car. There are some distinct advantages in a CD ignition system over a garden variety electronic ignition system and the MSD Digital 6AL is the benchmark for CD ignitions. However, while I appreciate the advantages on my combination those advantages may not translate to a street car. The multiple spark is a significant improvement over a non-CD system for my application. A 1050 CFM carb with no choke and a huge plenum single plane high rise manifold, and no carb or manifold heat, in ~9,000' density altitude creates a very lean mixture when the engine is cold. A garden variety automotive ignition system would have trouble lighting off this combo but the multiple sparks ensure it fires. The integral rev limiters (I have one for burnout, one for launch, and a top end limit) work very smoothly. The MSD ignition system works great for my application but is it worth the extra cost for a street car?

[FF33rod]

Naz, thanks so much for your response and insight. I've been following your "Divergent" build thread, that's quite the wicked machine!

I'm here to learn. As I mentioned, I really don't know what "state of the art" is for the engine I'm building up. If the MSD 6AL is a waste of money for my application (I certainly don't need multiple rev limits), that's cool and good to know. What would you recommend?

Cheers, Steve

[NAZ]

Steve, I really like MSD products (and Holley is a first class operation). First, so I make sure I didn't mis-represent my system -- my three rev limiters are not integral to the Digital 6AL but a combination of the 6AL and two MSD 2-Step units. As you know, the MSD ignition systems are modular and can be upgrade to a variety of combinations to suit your needs. For your application I suggest you look at the MSD Ready To Run distributer for your engine. The Ready To Run distributors don't need a CD box but it can be added if you find you need one. It has an integral rev limiter, an adjustable mechanical advance (you'll probably want to use the EFI for this function as it will be easier to tune), and a vacuum advance. The mechanical advance & vacuum advance functions can be locked out if you want to use the EFI for advance control. The Blaster II coil will work with this system and it will save you some $$ over a full CD type system. It will also make it easier to static time your advance before first start -- something the CD ignitions don't support. And just to repeat myself, it is easily upgraded to use with a Digital 6AL if you determine that necessary.

The reason I suspect you don't need a CD system is you have EFI that will tightly control the mixture during cold starts where a race carb on a big high rise open plenum can't be expected to. Your engine probably has a more pump gas friendly compression ratio than my 11.7:1 which is only pump gas friendly at this high altitude here in Flagstaff (it takes 110 octane race gas down in Phoenix, Tucson, and Las Vegas). But if you find you need the CD ignition box it's easy to add it later.

Have fun with your build.

[FF33rod]

Thank you, very much appreciated!!!