Winter Upgrade - Megasquirt

[bobcowan]

Time to be thinking about winter upgrades. I like to plan early to minimize down time, especially with a big project.

My EFI works pretty good. Easy to tune, pretty accurate. But, there's two features I would like to have, and my Haltech F10 won't do them.

First, I want to be able to run E85 at the track. More specifically, E70. It's cheaper, and runs cooler. Race fuel is up to about $8.50 a gallon. E85 is $3.19. The haltech F10 can't support E85 because of the accelerater pump. The F10 limits the pump to 100% of the injecter pulse width. With E85, I need about 120%.

Second, I want better control of the ignition advance curve. The old mechanical weights and springs are OK, but we can do better.

There are some really nice systems on the market right now, like the BigStuff3. Sequential EFI, distributerless, Wide band O2 sensor with self tuning, and full igntion control. But, that's about $2,500-3,000! Yikes! How much E85 would I have to burn to break even there?

So, my current plan is to build a Megasquirt II or III. What I read on the web sites is a little confusing and contradictory, so I'm not yet sure which one I'll build. Sequential injector firing would be nice, but certainly not that important; batch fire works just fine. And I don't need an idle control motor; might be nice, but I don't really need it.

What I do want is to use the Ford EDIS-8 distributerless ignition without an external exciter. And I want wide band O2 without an external control box. I think I can get both of those on II, but I'm not sure yet. To get both of those, I might need to step up to a III.

One feature I think could be real handy would be a dual map feature. To be able to switch between two fuel maps with the flip of a switch would be really nice. Like 91 pump gas and E85 street tunes.

Which makes me think "Why Not?". Factory dual fuel vehicles use a sensor in the fuel line to tell the computer what mix of fuel is being fed to the injecters. But I havn't seen any of the aftermarket computers with anything like that. I wonder why not?

To meet the budget, I'll probably build it myself. That's a pretty daunting task, so I'm not positive on that point yet. I havn't done anything like that in 40 years - and that effort didn't turn out so well. Remember Heath Kits? It's probably worth $150 to have a pro build it. But I'm a cheap bugger, so we'll see.

I read through various build threads, and that was pretty helpfull. And I'm spending time reading on the various megasquirt boards. When I understand it better, I'll start ordering parts. They need to write a "Meagsquirt for Dummies" book

Doing some preliminary shopping, I can do the whole job with all the features I want for about $600'ish. That's not chump change, but it's a whole lot cheaper than BigStuff3 or something similar. And that includes the new ignition system.

As I read through the on line manual, MS-II will manage EDIS-8 directly, with no exciter boxes needed. It only needs a crank signal. You need a cam signal for COP and independant coils. But EDIS is a wasted spark, and you can use the factory 32-1 trigger wheel system by itself. MS can even supply coils with a standard GM style cable connecter instead of the factory clip on style. That way I can make my own cables and route them the way I like.

I ran across a company that can accuratly mount the trigger wheel to the back of any balancer. Since I'm using a zero balance racing part, that might be the way to go. You can also use the factory crank sensor on a factory front cover; I like that idea. It will probably be more reliable than the Mallory Unilite I have now.