I'm currently tuning a 2004 silverado SS with a vortec SC. tuned pretty decent with 8 psi of boost. Install a smaller pulley and when I try pulling it on the dyno I get a reduced engine power code. I seen 12psi of boost right before the code. I'm used to using HP tuners where you just extend the maf table with higher boost and your good to go. I'm taken some advice from other posts and increased some of the map tables but no luck. Any ideas? do I need to upgrade to COS3? if so what is involved?