do you have tried to eliminate restrictions that are in the airbox
both inside and outside ??
I removed that "separator plate" when I was trying to find out why the Air-box made so much noise. It is thin and flimsy and I thought it might be acting like a "resonator", however it made no difference to the sound that I could tell. It just seems to direct the air to the centre of the filter so I put it back in.here is the outside airbox
the inside is the bulkhead nr 13
Are many differences between the engines , but nothing so difficult to modify >Restrictions?
If you want to know about restrictions, check out the airbox of a B-King.
It still whops out an impressive 184HP compared to the Busa's 197HP. (Some lost in the exhaust also).
Seriously, there are not much restrictions other than maybee the OEM airfilter in the GSXS airbox.
It even has a very efficient intake, although not "ram-air" due to no fairing guiding air in the (big) holes in the frame.
What holds the GSXS "down" in power is fueling (for EURO 4) and less agressive cam profiles. That is my understanding at least
Remap, GSXR-cams and it would be on par with the "donor" K5 engine.