with a stock exhuast you cant do shit!!! u will have to change it when u get a single as it takes a whoel diffrent downpipe. i got a rps kit and i love it. car puts down 500 rwhp and im on stock fuel, intercooler. i did get a vpc and some other goodies but either way look on spending $6500 to get it going decent....you cant just get a kit and leave everything alone.