Originally Posted by Stu @ M Developments
The screw is what we call a global modifier in as much as it adds a percentage to the entire fuel map.
If your engine is just borderline safe on boost, leaning the CO can and will destroy the engine when flat out. The correct base position is in the region of 5 turns clockwise and 2 turns anticlockwise to put you back in the ballpark, but this is of course dependant on MANY MANY factors such as heads, cams, sensors, fuel pressure etc etc...
thats what i thought, at the minute i'm not driving my car on boost (def not flat out) as it was adjusted down for the mot and other reasons
its all standard, head cams, all sensors work etc.
so the car has to be adjusted on a rolling road? or is the 3% @ idle a ball park for CO? i have access to an analyser but cant do it live.......as such