Are both of them giving 2.5" piping? Anyone did a comparison between the two? I have seen the Type One for DC2 and it has many bottlenecks.

 

Racing Spec-III is pretty much like a race exhaust system. It has 65mm OD piping and 0.8mm thickness. This system inproves a lot of peak power but low rpm ranges and low rpm response kindof slugish.

The TypeONE system for the DC-5 is 63mm OD all the way and there are no bottle necks for the DC-5. Reasons there were bottle neck for the DC-2 is cuz for the flow characteristics and fitment. Most of the 2.5" system doesn't bolt up properly and doesn't not seem to make double the power which a 2.25" exhaust can do.