I went stage 3 last Wednesday at Stealth and it was so disapointing! Dont fix what isn't broken to quote a phrase! 12 pound pulley and a front mount running 4.5bar fuel pressure. I lost 7 pound of boost and made 239 HP! We removed the I/C and replaced it with a piece of pipe and still lost 6 PSI! I could hardly make the pipe run any smoother either, hours of work and money wasted. I would stick with 8 pounds bud and save your money. I have a 12PSI pulley, belt and idler that have been on the car an hour if you are interested though.