Length may not be an issue. Pipe length and pipe internal volume determine its "tuned length" which can be used enhance parts of the torque curve. A great many 600hp V8's use 28" to 32" long, 1-3/4" diameter primarys. Merge collectors are state of the art, but what is down stream from them is important too. Straight long collector tube versus tapered, versus short, between merge section and muffler changes the torque curve as well. Then so does the muffler type, size and length. Gets quite complicated.
The only thing that can be said about the system in question is what Nev has already stated. All other opinions need facts to support those conclusions.
The only thing that can be said about the system in question is what Nev has already stated. All other opinions need facts to support those conclusions.