My issue to the best of my knowledge started with changing the clutch. I went with a lightweight twin disc set up 10 inches. I didn't think about it at the time, but the car now seems to need a higher rpm to idle cold. The flywheel is aluminum and always was, but I'm sure the clutch and pressure plate lost a lot of rotating mass weight and diameter wise. So I turned the idle up higher and now have a surging problem at idle. I will disconnect the charge pipe altogether and see if that helps , but that isn't the total way to know as you're altering a lot of the air flow. This is blow through maf right now and the car seems like it is shutting the engine down for a run away idle, yet in the past has had a run away idle. Run away idle because the idle air control valve is hooked up to the boost side for air, and not enough bypass in the past