If I remember correctly, one side of the controller valve is connected to the top port of the waste gate and the other side is connected to the charge pipe between the inter-cooler and the turbo. On the dyno, the engine makes boost, then stumbles at or near 4500 rpm, and then again makes boost up to the desired rpm shift point. I'm running an Electromotive ignition system and we have tried to turn the stumble out, with little success. This whole process makes a lot of hp and torque, but the stumble would make it very tricky if not impossible to handle on a road course. This car is a dedicated race car and will not be street driven.