I have the BMC street air filter which breathes better than the stock filter, but not quite as well as the BMC Race filter.
I couldn't tell you how much of a performance gain there was, as my bike was tuned immediately after I installed the filter,
PCV & Yosh exhaust. It was all done at once.
The BMC street filter provides more protection than the BMC race filter, but at the expense of a bit of performance.
G'day Paul, I got the carbon through Hard Racing. They were really good to deal with and the price was the cheapest I could find anywhere at the time.
Freight was a bit of a sting in the tail, but that was due to the awkward and long shape of the tank covers and the fact I also got a PCV & BMC air filter at the same time.