Awesome News!!
For me at least.
After analyzing all the data and posting the above post, I tried to devise a new test that would either prove or disprove my theory.
Well, the overall idea is that there is turbulence in the exhaust, and that the higher the exhaust velocity the less of an effect the turbulence would have. Also, when the secondary's opened up it would always go away. This is an increase in the intake charge which means more exhuast, which in turn means that the exhaust velocity has to go up to get rid of the exhuast assuming the pipes are the same diameter.
Well, I figured that by wiring the secondaries open I could increase the airflow. So I went out about 20 minutes ago and tried it.
The stutter seemed gone!
I was able to do a 5th gear pull from 1500 rpm without the slightest surge or stutter.
Apparently there is a small stutter right about 1000rpm now, but it is gone by 1500rpm.
This is all in agreement with my theory in the above post.
It was very simple to try this test. I took some wire and after removing the air intake boot I could see the spring assembly where the imrc is actuated by a cable. I just took some wire and tied it to the throttle cable brack to keep them open.
I advise those of you with the stuttering problem to try this test. Just because you haven't gutted your pre-cats, you may have some turbulence caused by clogging in the pre-cats.
Not all people may be affected by this, but if you have the problem when the engine is warmed up, but not when completely cold, then try it as the temperature of the manifold can greatly affect the exhaust flow characteristics.
The end result should be that a good set of headers will cure the problem.
warmonger
