Has anyone seen gains from an after cat x pipe, it seems there should be a gain going from the 2.25" h pipe to a 2.75" x pipe would free up some exhaust flow.
I have no data but my experience only led to a sound change. It essentially took the pulsing out the exhaust from the stock h pipe. I could not tell any difference power wise but I liked the moderate change in the exhaust. It was only slightly louder at idle but sounded more refined at moderate to WOT. I used a BBK after cat x and it took a few adjustments to seal but overall a good fit. Did you end up finding a midpipe?