I might be able to help with this. I just added a ford racing x pipe to my 2011 V6 mustang
. Pretty easy to install, just cut and clamp just like they say.
In terms of performance gains it was pretty minor. I picked up a bit of HP after 3500 RPMs or so: not much however. Motor seems to run a little smoother at higher RPMs as well. I bought mine for $50 bucks from a guy that sold the car before he installed it so it was an ok value. Otherwise I'd be disappointed if I paid $179 for it new
One other note - it didn't make the exhaust sound any different. I'm running BBk shorty headers, factory Cats and a magnaflow street exhaust.
Lastly, although people recommend removing the cats for better performance I've talked to guys that have dyno'd that change and found very little difference. I'd think twice about removing them, especially if you're in a state that is pretty stringent about that stuff
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