In my case total net power gained on back to back dyno was sub 1rwkw changing from stock dump & front pipes to tune agent dump and front pipes. Same 2.5" cat back on both runs. Other members have noticed similar results -this style of dump pipe was very popular when they were released under the tune agent label probably 10 years ago because they were so cheap by comparison. The design is not very good (small pipe diameter even compared to stock) and the divorced section way too short to actually reduce turbulence.
Great post!! Thanks heaps From my experience, the 2.5" system starts choking at 400+rwkw Definately started choking at 450rwkw
