DIY fuel injection?

[440roadrunner]

You may remember I have a "lo budget" Dodge Dart I play with, currently running the now elderly/ obsolete Holley "Commander 950" TBI setup. The tuning procedure as "all manual" so a little clumsy.

I'm thinking of trying out a Megasquirt controller. Any experience, thoughts, with these?

COST is most definately a factor.

[Burgerman]

Never played with one.

Plenty of good reports and very flexible.

May be easier to just look for a similar sized/cylinder count motor in the breakers and steal all the important bits though. I have done scratch built turbo/nitrous/fuel injection systems in a similar parts bin way. But I had a rolling road here complete with 4 gas exhaust analyser to aid setup and not melt anything though...

[440roadrunner]

Ok, so pick your brain?? LOL. What sorts of ECU have you used and do you find likeable?

For example, "some guys" over at the "Binder Planet" a bunch of International (IHC) vehicle enthusiasts seem to lean towards surplus GM computers, which require re--burning a chip. Computers such as the Jeeps (Chrysler engines) are/ were different than the Mopar stuff which is fairly user "un" friendly. I don't think you can really re-program the Mopar ones.

[Burgerman]

Most of the stuff I played with was generic weber marelli as used on many cars bought new parts to fit to big turbo bikes with 300 plus hp... Or programmable race stuff on ducati racers. But programmable with hand held 3d devices or a PC. Not cheap though. It was pick n mix from new parts.

If you are looking at cheap, then you likely dont need reprogramable, almost all of the stock big engine v8 system for egs will need no or hopefully no reprogramming. If you have more airflow it compensates as long as you set max power correctly... Most have similar ign advance curves, or very close too.

It may be generally weak/rich to start with, but thats a matter of changing fuel pressure, adding resistance to sensors, etc to convince it to do the right thing as needed. Even injectors can be swapped for bigger/smaller if you really cant get around it other ways. Cylinder count, turbo or not, and max hp output are the things that need to be similar to make it easy.

Fuel pressure or injector size sets mixture at full throttle and its not closed loop here. You need a rolling road. And set for max power and a touch rich or use leaded fuel and aim for tan to light brown plug outers on a full-power top gear 800 yard plug chop...

Below that WOT point its usually just closed loop and self correcting. And so will sort itself out if within range. Except at idle - there is an adjustment screw for mixture here. Idle speed rpm is an idle air control valve. Advance curve or ignition timing needs to be correct at full power and the rest will be close enough - most advance curves are pretty similar. If there are problems aftermarket timing boxes or adjusters are available.