Thread: EFI Options

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Just remember firing orders are dependant on how they number the cylinders--and theres only a couple variations---but anyhow ---all you have to do is switch wires for spark plugs and injectors

It's a separate part, not for highway use and all that. I think they use the brain out of a STS and take out all the whistles and bells and leave the engine management system then tweak it. It comes with generic program to get you going then you can tune to your specific needs.
Ken

I learned a few things today talking to Erik at the House of Boost, a tune/install shop in the KC area that generally works on outrageous HP engines, like an 1100 RWHP Mustang - crazy fast, but still streetable. These are my interpretations, and my limited understanding after an hour with the guys doing the installations.

It seems that 600HP is the real break point - below you can use what you want from TBI to direct port injection, and from batch fire to individual fired injectors. The real key to having to spend the extra money to fire injectors individually (more ECU) is that the big injectors that are needed to flow to the >600HP engines generally can't turn down far enough to give good control at idle - batch firing (groups of four, generally) pushes the engine too rich at idle so individual firing is the answer, or even going to multiple injectors per cylinder, and turning some off at idle.

For an engine in the <600HP range the ECU can control the A/F ratio across the load range in batch fire mode, or even using TBI. In fact, there are said to be some advantages to having the injectors farther away from the head, to gain the cooling effect of the fuel in the air which tends to increase the density of the charge. It really comes down to the "look" that is desired for the "lower" HP applications (I'm still having trouble with a 425HP engine being "lower" HP One can go "trick" and eliminate the distributor, firing hidden coil packs from the ECU, and an "in your face" throttle body and air cleaner setup; or keep a traditional distributor/MSD box for timing, and let the ECU handle only the A/F ratio, hiding the TB under a traditional air cleaner, looking like a four barrel carb to the casual observer. The beauty of the better aftermarket ECU's is the A/F ratio map that lets you tune point by point, for all power conditions, viewable via serial port on a laptop. The ugly is the ECU cost

Not sure what I will end up with yet, but I feel I have a little better understanding of the basics, and that I don't "need" direct port, individually controlled injectors for a "little" 347