Originally Posted by Karlos G

mk3cab no it doesnt have any effect on your on boost mixture, that is set by the EFPA (electromagnetic fuel pressure actuator) on the side of the metering unit(little black box).
Ideally you want to be seeing 14.5 to 15.0 on Idle/Light cruise, progressively dropping to around 11.5 (give or take a bit) on boost and at higher RPM's so your not far out.
Those figures came from C&B btw!