I went to a bike shop sale last week.. and they had a set of Yosimura pipes and mufflers for an SP1,.. excellent.

The primary pipes are stepped larger and do not appear to actually join.
I would like to get pipes like that for the Fire Storm ,..

.. but apparently they are not available

and the SP1 pipes won't install onto Fire Storm. ( the primary pipes interest me more that the mufflers)
?? Does anyone know if there is a system like the Yoshimura big bore pipe availabloe to fit Fire Storms ??