My car in stock trim with just a k&N replacement dynoed at 366 rwhp. My first vist to the track with this car resulted with a best of 13.4 at 109 My 60 ft was 2.14 I know Practice practice. since then I have added the magnaflow cat back and high flow x-pipe still with the K&N replacement. I made another vist to the track thinking I would pull some 12.7 or so with the exhaust addition. My best was 13.3 at 111 mph increase but time is still low 60ft was 2.23. Let me mention that my cat back is not welded but I see no signs of a leak. The numbers do not add up I know I need to improve my 60ft times but still i only see a 12.90 or so if i were to nail the 60ft. I have a 10" S&B air filter on the way hoping this will get me some where. Dose anyone think I should try and but the stock h-pipe back on? I remember some one stating they lost a lot of lo end torq on the dyno with the magnaflow x pipe.