View Full Version : eliminating IACV questions

03-20-2009, 12:01 AM
well i never did get a real good answer on this.

here is the run down. A buddie of mine is doing a little bit of fab work for me on my intake mani we are using a q45 TB on it. Now the question that he was asking to me was, can i get rid of the IACV and possibility use the fast idle function on the q45 tb instaed? for now i am just gonna be on a rom tune, and I will be running some fairly large cams.

If i am able to use the fast idle on the TB instead will there be any kinda wiering that i will have do? or would I be better off just leaving it be.

please give me your thoughts on this matter.

04-01-2009, 03:17 PM
The IACV on the sr20 works off the ecu- the ECU provides a pulse that determines the amount of air passed from the coldpipe to the intake (bypassing the throttlebody)

without this device there, of course the engine will run, but it will be dependent on the air from the throttle body, which is normally closed at idle.

the negative side to this is, during a cold start, the idle will be very low (because there is nothing to bring in extra air that cold idle requires) and you may find the idle gets a bit too high in some instances as well, as there will no longer be anything correcting your idle speed, its basically "in the hands of he whom we dont name" at that point.

I did this, ONCE, and regretted it. The sr20 has a wide variety of idle conditions on the street, a variety of airflow needs, and should maintain the IACV unless it absolutely MUST be removed.