Just wondering if anyone has before and after time slips/0-60/1-4 mile etc from before and after downpipes. Perferably this being the only change other than tuning for the pipes. I have seen some butt dyno comments that elude to both better to no change comments. I know there has been documented HP increases of 10 to 20 hp range but just wondering in the real world if this really equates to quicker times? I know that 10/20HP can be hard to detect in a 4K lb car but I haven't seen any time slips or justified information to make me pull the trigger on $900 for catted pipes which I would need for emissions.