Process West Race Air Box Kit, Suit Stock Turbo for Ford Falcon XR6 Turbo FG [PWFGCAI02]K&N Filter Supplied 6" to 4" bell mouth Utilises the stock location for the battery Suites factory turbo Our 4in race air box system has been designed for extreme power levels. Utilizing the area normally occupied by the battery we have been able to design the ultimate high horse power intake. The air box uses a massive 6in internal diameter K&N filter which mounts onto a 6in to 4in bell mouth which connects to a internally wire re enforced molded