Stock Y-pipe Cutaway

[Blown09]

Pretty crazy how restrictive the stock y-pipe is on the 4.6. Cut the stock off today and went back with a flowmaster Y pipe, 2.5 in 3 out(a really great design-surprising I know). Small piece of 2.5 piping next to it for size comparison. Second pic is the crossover from the passenger bank. You can see the left bank is even worse with the double pipe(in the second pic).

Need to datalog the truck again, but she feels MUCH happier now. No muffler for now, so she’s also incredibly loud
Didn’t want to go back with the F150 muffler as it’s not a true 3” all the way through, 2.75” inlet and eventually opens to almost 3” at the outlet. As much as I liked that muffler, I wasn’t about to go through all this hassle to put another bottle neck back in.

 

[FoMoCoMotion]

Any pics if your full exhaust set-up?

 

[Blown09]

None with the current muffler setup, but I do have some when I initially finished it and it was straight piped. But it’s as follows now:
Stock cats, 2.5” piping off cats(outlet of cats opened to 2.5”), 2.5” to 3” Flowmaster ypipe, 3” piping to stock 2013 f150 muffler.

I didn’t want to put it back in, but I couldn’t live with the drone/loudness of the aftermarket muffler setup. Plus, the f150 muffler didn’t affect power all that much(probably less than 10hp), but did get sound levels back to respectable.

 

[FoMoCoMotion]

Thanks! Gives me some ideas!

 

[Blown09]

From the ypipe back was all temporary… don’t mind the “hangers” lol.
I will say that welding up the driverside cat is damn near impossible without a flex-head mig and a mirror. If possible, the best way to do it is tack everything up, and drop the ypipe. Had I had the time to do that, I would’ve been much happier with the outcome.