What is this wastegate spring that supposedly adds 20 HP found in TAP1.com's Stage 2? http://www.tap1.com/Modifications_by_Model/S4_S6__20_Valve_/s4_s6__20_valve_.html Is anyone on the list running a modified spring such as this or has anyone modified the stock spring for similar results? Does this mod really make 20HP? Seems too good to be true. Thanks, JR