MSefi.com read only forum (Jan.15,2018)

Newbie to the forum and I have been reading everything I can. I am trying to plan my project but before I get too deep I want to see if I am on the right path. I have been reading but is bewildering the amount this product and site have grown in a short amount of time!

Engine is a big block Chevy displacing 7.4L/454 cu inch with large ported cylinder heads, solid roller camshaft with about 14" idle vacuum making about 550 HP at 6,500 rpm.

My current plan based on what I have read is:

1) MS-II to control fuel and spark
2) Enderle Indivdidual runner manifold with 8 throttle blades and runners with velocity stacks and air cleaners on top
3) Ford EDIS like solution used in this link http://www.DIYAutoTune.com/catalog/mega ... -p-65.html because I can get the parts cheap and it looks rock solid
4) I want some type of idle control for better cold start running and idle control when it gets hot
5) Innovate wide band O2 (already using to tune carb)

Question 1: Do I need to build a vacuum log from each individual runner to a central location and feed that signal to the MAP for MS-II to work correct?
Question 2: If I build a block like the Jeep version that uses a GM stepper IAC will this give me good start and idle stabilization when combined with the cold start enrichment?
Question 2A: If I build a vacuum log to signal the MAP can I just plumb the IAC into this circuit? If so how big does the vacuum line need to be? 1/4"?
Question 3: When using a wasted spark dual coil set up where do you get a tach signal?

pcf_mark,

1. You will probably need to link the cylinders together to get a stable MAP signal, and tuning will likely work much better that way.

2. This will work, but only if plumbed to all cylinders (you can likely use the same plumbing as for #1, if there aren't significant restrictions (i.e., the line inside sizes are big enough, etc.). This is going to be a matter of experimentation, but as a guide the IAC passages are about 3/8 to 1/2 of an inch or so. However you would be dividing that by 8 cylinders, so the lines could be much smaller (3/16" or so, though there are wall effect restrictions...). If I was doing this, I would start with 1/4 inch lines.

3. See this: http://www.megamanual.com/ms2/EDIS.htm#tach

Lance.

Thanks Lance. I am going to build the vacuum log to help with tuning and IAC all in one function. You hit it with the vacuum signal split across 8 runners - I'll try 1/4" to meet both functions and see how it works out. I may sketch it out and post for feedback before I drill too many holes. I think I'll put the vac. port above the injector so it does not draw in any fuel vapor if possible.

Next up - finding 45# - 50# injectors without going broke!