In short, I'm experiencing a stuttering/hesitation problem.
Here's the symptoms,
The problem was occurring around 4500 - 5000 rpm at 13.5psi
The stuttering greatly reduced when i dropped the boost back to about 10psi
I replaced the spark plugs with NGK bcpr7es' and that seemed to help a little but not much.
I adjusted CAS to full clockwise to retard ignition timing, dropped stuttering to 2500 rpm at one stage, but seems to occur more predominantly than before at about 3500 rpm and on full throttle would not increase in revs, however lighter throttle and it would.
The problem started a couple of months ago. With the silencer out i could hear a popping noise under high load at 13.5psi around the 4500 - 5000 rpm range but the stuttering was barely if at all noticeable. The problem has been steadily getting worse, and I have not recently driven the car without the silencer in to see if the popping noise has changed in any way.
If anyone has any ideas please let me know,
Thanks.