IAC Valve and ITB

I was researching Megasquirt, and the associated inputs, outputs, and control systems. There is talk about the IAC Valve, and whether you are going to use it or not. IAC stands for Idle Air Control, and essentially it is a stepper motor driven valve that opens when the engine is idling. It prevents the engine from stalling when the throttle is closed.

There is a problem with this, if I am going to use ITBs, or individual throttle bodies. On the stock Zetec, there is one IACV, and one throttle body to match. When I go to the ITBs, I lose the simplicity of a single throttle.

The IAC should allow me to properly drive the engine, and not lose the efficiency of EFI. So I want to use it.

A quick search on Google, turned up this:

IACs and ITBs

It discusses where to place the openings, and provides a little bit of insight into the problem.

So here's the plan. Take the Zetec IACV, add in some air openings in the bottom of the Suzuki throttle bodies opposite the Suzuki injector ports (which will become the vacuum hook-ups), and hook these into the output of the IACV.

With some nice engine dressing, I should be able to make the whole thing look good too. The stock fuel rail running into the stock (Zetec) injectors, in the stock intake manifold ports. A little bit of cleaning up, and the stock system shouldn't look too bad. Add in the ITBs, and some nicely dressed vacuum lines, and some nicely dressed intake lines running underneath, and it should look downright fierce.

This solution allows me to use everything I need. Or so I hope.