i have a boost controller yes is a manual but its a good one. ive noticed that it goes into limp mode over 15psi. now i have it set to spike right at 15 and hold 13.5 by me using a boost controller is the ecu not maching the air/fuel ratio? other word by me tampering with it am i causing it to now run lean. other than bypassing the m75 valve, an ecu flash would fix the "limp mode" problem right. i have the money but looking for the best. im deciding between the revo stage 1 or the garrett. i havent heard anything good about the authority and its the most expensive. which one have you vdub guys and girls had the best luck from. i dont have much help where im at, im the only gli in town and the only aftermarket vw around here. its all hondas!!!!