Here is the description from Kami's website:
Also you have the choice of downpipe to fit stock location, or our full out 2 1/2" outlet downpipe, specialized for supercharged vehicles. (Which does require modification) Dyno tested and race proven.

Is the length of the full 2.5" downpipe and collector the same legth as stock?
I need to know what size / length test pipe I need to mate the header to an SMSP exhaust. The SMSP is coming off of an GSR, however it has a Toda header on it and a test pipe with an unknown length (The car is not near me to look at).

Thanks guyz.

 

I had a HUGE misunderstanding with PTuning/Kamikaze. They were able to "fix" the problem but extra downtime and me paying for additional shipping were the results.

I have a JRSC so naturally I ordered a 2.5in collector version. I got sent one with a 2inch collector! I called up PTuning immediately and they told me that they'd call Kamikaze. Kamikaze tried explaining that it was in fact a 2.5inch collector BUT has a 2inch reducer. WTF?!? REDUCER? To the best of my knowledge and everywhere I look, the actual opening is what everyone refers to as the collector. This went on for a while, but they gave me an option to send just my downpipe to the main facility and they would send the one I wanted back with me paying shipping both ways, thus losing extra unexpected money out of my pocket, downtime, and a missed dynotime schedule.

FOOOK!

note: if you want 2.5inch outlet, make sure you talk to somebody instead of straight up ordering off the internet