Since I'm up I'll answer this. Reason people switch from the y pipe to the x-h pipe is because they cause a scavenger effect. A y pipe does not, that's why you make more power with a x-h pipe. Just like if you had long tube headers, they have no restrictions. They pull the gases right out of the cylinder which causes more power. With just a y pipe you will not gain much if anything but that goes for a true duel set up aswell. You might gain 6 or 8 more rwhp from a duel exhaust setup then a y pipe. Long tubes maybe 15rwhp with duels. since your stock y pipe is 2.5" you should go with 2.5" piping if you stick with the si/so or si/do setup. 2.5 will have better velocity which might increase power numbers. Hope this helps.
Thanks bro. I may not do anything because I am fixing to buy a house so if I can do it it will possibly be a min. I have time to research some sounds. J.Wal
I know this thread is a few days old, but I like exhaust and have done some research pertaining to mustang's mostly. I think you should get a h-x mid pipe, it will definitely help. Also, instead of high flow cats, you can save some money and just gut your cats out, save some money. And they wont make it too much louder either. I realize you said you might be getting a house, but I thought I'd give my $.02. Sent from my Android using Tapatalk
Well I personally would keep the cats and just replace them with high flows. Their are custom tunes so you can run them without cats but sometimes you still have a engine light which annoys the hell out of me. So I'm keeping cats.
