iang, I know nothing about that!?!
Just checked with our parts chap on that score, no parts listed.
Checked with Duc UK they don't know either!!! Sorry mate, someone is telling porkies I fear!!!
Like andyb I find it highly unlikely / impossible!
Not only is andyb right about the diameter of the backbox inlets (a restriction that you just can't get round without cutting it open!) but there is also nowhere for the additional pipe to route!
On the 54 / 57mm system the pipes are offset and the RHS foot peg is spaced to facilitate both pipes being shoe-horned in the cutout in the swingarm for the standard pipe.
Advice is this : -
If you want a few bhp, increased torque and that DUCATI sexy noise, fit the asymetric system.
If you are thinking of maximising BHP and are thinking of going further down the tuning route (or you just like having all the bells and whistles!) the 54 / 57mm is the place to start and looks the bogs dollocks!
Pipes and fuel injection is only the beginning of tuning. There is loads that can be done given a big enough budget!!
But if you are thinking a bit further down the line, start with a good exhaust system that will cope with what ever you do internally to the engine.
Lastly, ALWAYS get the CO's done, preferrably on a dyno, it's the only way to get it feeling crisp!
You know where I am if you wanna word!