Idle control v. race car

[TouringBubble]

I'm going back and forth on what to do for idle control for the Beetle.

I built the MS unit to control a PWM idle valve (Bosch European style ... BMW, Volve, VW, etc) but I really don't want to run the ridiculously huge lines those valves require. With the dual plenum setup I'd have to run 2 and deal with splitting the line and it became a bit more than I wanted to deal with.

I also considered using a small solenoid for a simply fast idle, but it really wouldn't make a huge difference. Maybe 200 RPM idle increase. Not really worth it.

I also considered a manual control from the dash. That's not going to save me any trouble really other than bypassing te ECU, which is already set up to run a valve.

Or, I could leave it without idle control and just hold the throttle for a couple of minutes on the occasions that I drive it.

What would you do? Is the extra plumbing worth it for a stable idle on cold starts?

[JohnW8]

Several CSP Miata drivers have removed the IAC valve from the car because trying to tune the friggin' idle with Megasquirt is a pain when the factory IAC isn't really supported by MS. Darryl has his working... sometimes other times the idle surge will lull the competition into a hypnotic stupor.

[TouringBubble]

Yeah, configuring a factory valve can be a pain, I know. the Bosch valves are pretty standrad in the MS crowd and are well supported. All the kinks should be worked out of it.

How do the Miata guys like the IAC removed? Is it an issue?

The only experience I have with it is on the MX-6. We removed it because it was stuck. We would give it throttle for like 2 or 3 min in the winter and then it was fine. This was after Sean tried to drown it too, so I'm not sure if my perception is skewed. lol

[JohnW8]

Open the throttle plate set screw and it idles fine, if not a touch fast once it warms up.

[TouringBubble]

Yeah, a touch fast is no problem. Kind of what I'm thinking. The issue being I have to sync the 2 TBs properly. Should be fun. lol

[Cholewa]

Just use timing and fuel to keep it idling ok. That's what the volvo does... sometimes.

[Chuck Baader]

Remove all that crap and plug the holed. Open the throttle plate enough for the motor to idle at 11-1200rpm cold. That should give you a 15-1600rpm idle hot. WIN!! CB

[TouringBubble]

Due to my oiling system I'd prefer to not have a 1500 RPM idle. My lifters don't get oiled well until around 2200, so I'd rather stay out of the no-man's land between 1000 and 2200. Otherwise I wouldn't care much.