I've decided to replace the bypass valve with a blow-off valve. I know my Kuwaiti friend, with the URD kit, managed to gain a couple PSIs by cancelling the bypass valve and relying completely on the blow-off valve. It is very likely the cause of the problem. I tested it by blowing into the valve while the car is off, and I couldn't blow through it. But probably with proper pressure it is able to blow through it during boost. My Rotrex sure has been through serious abuse when it was on the Alpine mounting kit. The tensioner wasn't dynamic, the crank pulley wasn't perfectly centered, and the belt would occasionally jump out of the crank pulley guides resulting in tremendous tension on the two pulleys, which is probably what broke my timing chain cover twice. But since I put on this Bullet Cars mounting kit, the supercharger has been trouble-free, a perfectly designed system, kudos to them for doing such a good job. The loss of boost only happened very recently.