Volumex with multi-port injection

[markw]

I have a Beta Volumex engine installed in a Fiat 124, so a DCOE conversion has never been an option for me. For the last 15 years (at least), I have mentally explored the idea of multi-port injection (injectors positioned on the inboard manifold). It would be hard to argue that this is a cost-effective improvement, but I like the technical challenge.

I have seen several good conversions around the web (I'm looking at you, @west!). To those who have made the conversion, have you been able to quantify the improvement the conversion offered? I know the theory of why this approach is superior, but I would like to hear how it addresses the shortcomings of "the log" in practice. Are there any gotchas I should be aware of?

Before you caution me, I am conscious of how big an effort this project would be

[WestonE]

Mark

This is a huge topic and I have limited time. Fine control is the advantage. Power comes from maximising cold Airflow  BUT the VX engine airflow is unbalanced so the ECU MUST have cylinder trimming to match fuel to air plus the VX was designed to run wet so out board injectors as well. I run the inboard sequentially which needs a cam sensor (modified from an integrale). The OE inlet manifold is terrible for flow. It would be best to turn the VX on its side and have it feed a custom plenum like the later 037 designs.   

I will one day re-do my Volumetrico inboard manifold for my Montecarlo. Without the control from the Link G4 Fury Ecu it would melt.

Enjoy

Eric   

[markw]

Maybe I'll dump my "injecting a volumex" questions here for the benefit of the forum. Does anybody have a guide on what a suitable throttle body diameter for a volumex engine is? I'm guessing ram-flow will have a negligible effect on the performance of a supercharged engine. A local guy has used a 65mm, which sounds reasonable, but I would love to know the logic behind sizing on this kind of engine.

Cheers