Anyone try Holly Pro-Jection?

[Guest Anonymous]

They make a 300 cfm model that'd be sized well for many of our variously modified motors.

They sell a closed loop kit that is likely cheaper than buying all the parts individually (especially if you've priced Motec computers lately).

It's an easy first step towards your own DIY port fuel injection.

Kinda makes me wonder.

-g

[Guest Anonymous]

I've been looking at EFI conversion stuff including this system but have to warn you that as an Edelbrock employee, my opinions are oh so biased...

That throttle body (Holley PN 500-1) is basically the same as the stock throttle body in 1982-1986 GM 2.5 L 4 cyl, (Buick Skylark, Pontiac 6000, Chevy Celebrity, others), bored out to 2" - stock is somewhere around 1.43". The throttle body is a Smog legal replacement for these applications is compatible with the GM computer, though almost any aftermarket ECU can be configured to use the throttle position sensor and fire the single injector...

The kit you're probably talking about I've seen marketed as a replacement for the Carter 2-barrel for Jeep 6 cylinder (4.2L) motors (Holley PN 501-12), uses 500-1 but with a 90 pph injector. The Pro-Jection system is good because it is cheap, but if all you want is cheap, you can find junkyard GM ECUs and throttle bodies all day long that will perform as well. The limitation in Throttle Body Injection systems is that the fuel is injected at one point: the throttle body. TBI was always sort of a bastardized stop-gap between the carburetor and true port injection - as such it suffers from many of the maladies of a carburetor including uneven fuel distribution between cylinders and fuel seperation from the air fuel mixture (fuel, even when vaporized, is heavier than air and when the mixture rounds a bend in the manifold, the fuel's inertia carries it towards the outer wall of the runner). Also, TBI systems use the throttle position and RPM to estimate air flow into the motor, as opposed to a mass air flow sensor or manifold air pressure sensor which (either or both) are necessary for a system that can accurately adjust fuel mixture for atmospheric conditions.

I'd save your time/money and get ahold of the 318i L-jet system, it's batch fire, but at least it's a port injection system, and if you add an engine position sensor of some sort, you can convert it to a sequential-fire. There are a bunch of programmable ecus out there, I'm leaning towards the LINK computer for my preoject, it can act as a stand-alone fuel computer that I can use with my distributor, later I can use the same ecu to control my ignition, and it's pretty cheap, they're based in New Zealand, but their US distributor is: www.performancedevelopments.com

Rich