Twiss' supercharger+EFI

[Rhinoman]

Yes it does, it needs around an Amp at something like 20Hz

[twiss]

Is it a stepper motor for the IAC? Or just On/Off?

Doing a bit of looking around seems like the IAC is built into the throttle body?

[Rhinoman]

Its a PWM signal, yes its fitted on the side of the throttle body

[twiss]

OK so apparently to drive PWM idle valve I will need to replace a transistor with a higher rated one... I will bear that in mind!

[Rhinoman]

What rating is the MS driver?

[twiss]

The standard driver is a PN2222A transistor... apparently can handle up to 40V 1A
They recommend replacing it with a TIP120, which is 60V 5A

[Rhinoman]

A 2N2222A? that's not going to drive a lot at all. The TIP120 is a darlington pair, its ancient tech but it will work OK if you add sufficient fly-back protection.

[twiss]

I'm thinking I might start off with a bosch fast idle valve, I would like to have PWM valve working but its probably going to be quite fiddly!

I think I will have to look at bypassing the standard IAC somehow and just using an idle valve powered with a relay... apparently the 2222 transistor can at least power up a relay! haha

If left disconnected would the standard valve stay open or closed?

[Rhinoman]

I'm sure that the IAC is closed by default, its spring loaded. A relay won't last any time at all and probably won't be fast enough anyway and the fast idle valve will give you no idle or 2500RPM. The IAC is designed to run at 50% duty cycle so it can add or subtract air. The IAC is also used to give a 'dashpot effect' while decelerating which makes it less prone to cutting out when you stop.

[twiss]

Sorry, I mean I was just going to use a solenoid type fast idle valve to open at start up and close again at running temp

bosch 0280 140 505 is the one

Shouldn't be going on and off much so I would have thought a relay would be OK for that?
I was hoping a fast idle solenoid would work for now, as Im going to have the components to build probably 3 PCBs I was thinking about making the first one with just the mods required for low power ignition control, then with the second I will be working on adding a flyback board for high power ignition (coil packs) and for the standard IAC valve

I just want to keep as much high power components out of the ECU as possible for now!

I should be able to getting running with a fast idle solenoid though, shouldn't I?