VTT - S55 “GC” Turbocharger Upgrade KitWHP Level supported (with proper fuel, upgrades, and tuning) Stock 800WHP VTT S55 GC Turbochargers. GC stands for Game Changers and that is exactly what these do! They bring a fully new casting Stainless Steel turbine manifold housing, all new compressor housing with single piece high flow inlet, as well as our tried, and true V2 GC CHRA with a Mar M246 GTX28 profile turbine wheel, and custom compressor wheel. These turbos have NO core charges, keep