The newest TVS (Twin Vortices Series) hybrid-roots superchargers are an amazing feat of engineering – efficient, compact, and quiet. But what if you don’t want to be quiet. Until now your only option with a rear cog pulley upgrade was to go to either an under-driven or over-driven ratio. This is great if you are trying to run lots of boost, but if you have a 1:1 rear ratio already that could mean drastic changes in blower speed that you would have to compensate for with different front pulley. Fortunately we have solved this dilemma with our new 1:1 cog pulley upgrade for our TVS-based supercharger kits. So now if you have a kit running a 1:1 rear ratio like on the TVS2300 for the 2010-2011 Camaro or the TVS1900 for the Pontiac GTO or are looking to up the boost on your under-driven TVS kit without using a smaller drive pulley, we have the solution for you. The upgrade kit comes with the 2 cog pulleys, belt, and installation instructions (Note: Installation may require removal of the supercharger unit if there is not sufficient clearance between the pulleys and firewall).