Smitter

Monster street-port, idles beautifully @1000rpm with 550/1600 injectors & alluminum flywheel
only pulls about 10 vac. motor is brand new.
trying to find a good tuner, but the idle doesnt concern me. (at least until i read banzai's post)

arghx

iTrader: (3)

I only use Idle IG control if I'm using the ISC to control idle. I didn't realize how effective it was until I started logging it. I had the ISC deleted on my old setup and controlled timing using the IGL/IGT maps after setting all idle speeds to 0 in the Datalogit. With enough ignition timing that idled fine, but I really missed having an idle up for electrical load and the cranking assist function of the ISC, so I put it back. The ISC goes full open during cranking, which is kind of like you hitting the gas pedal during cranking to increase intake air. Note that this is using 4 BUR9EQ plugs with HKS Twin Power and FC3S leading and trailing coils.

You may want to re-learn idle if you choose to turn it on. Save your map with a DL, reset the PFC, reload the map, and perform the learn procedure. While the idle is learning, log Basic only (in that log, I am logging advance). Then you can get an actual curve of the vacuum reading. Another thing I noticed is that my car will idle more stably with leaner mixtures with the ISC installed. I have all top feed 720/1680 injectors with a Mazda OEM 6 ohm resistor pack. Idle AFR is high 12's low 13's, and I do not use negative lag.

Other engine management systems let you control the entire range of automatic timing advance/retard when their closed loop idle ignition control systems are on. This is a map for an Evo IX on the AEM EMS:

Wargasm

Mine will run acceptably well down to about 750 RPM but it gets slightly more lope-y and is also easier to stall (particularly with my light flywheel).

Just fo the sake of smooth starts and no lope, I have it set for 1000 RPM where it makes about 16 on the vacuum gauge.

I would say my street port is "medium" and I have 550 stock primaries.

Speed of light

iTrader: (8)

Pineapple large street port, very lumpy @ 750 rpm even when tuned (due to high overlap & exhaust gas dilution of incoming charge). Smooths out noticeably at 800--850 and is very smooth at 850--900+ rpm, once all of the air is moving through the motor/ports in the correct direction.

Mine pulls about 10-->11Hg vacuum at idle, which really isn't that low.... (This is similar to a V8 at idle with a mildly aggressive cam.) More radical ports (and cams, respectively) might only result in 5" Hg, which is again, ok, if you TUNE appropriately for it.