Has anyone put mega squirt on a 400? If so what were the results and what components were used? I.E. Tbi or multi port. Size of injectors and throttle body?

 

Megasquirt is a speed density system, and it shares the problem with all speed density systems. It relies on a MAP sensor reading to calculate the fuel requirement at a certain load and throttle position. It uses a table to convert these readings to air flow. No one can give you the exact values that should be in that table. You must figure that out yourself after the system is installed. This task leads most of those who try to give up after a while, and switch back to carb.

I am using a '93 Mustang EEC-IV with a 2003 Cobra TB, 42# Injectors, and a F150 Lightning 90mm MAF. This is a Mass-air system, and air flow is read directly from the MAF. There is a MAF transfer function that can be obtained from the MAF maker. All that is needed is some tweaking. I use a Tweecer to reprogram the EEC-IV.

There is an aftermarket unit made by Mass-flow(mass-floefi.com), which is a Mass Air system. They will sell pieces or a turn key setup. This is the only aftermarket system that I would recommend.

Just a note, you need a single plane intake manifold to use fuel rails with the injectors.

Check out these sites.

www.fordfuelinjection.com

http://www.mass-floefi.com/

and the Tweecer group on Yahoo.