Good day everyone... this is my first post... nice website... I have an 06 Busa, red, not too many mods... yet!
Anyway, I was reading some of this material and I thought I would give my 2 cents worth. I am a fighter aircraft mechanic and as such inlet air flow is a subject that I am fairly familiar with. On the aircraft inlet flow has alot to do with how the engine performs. The inlet is curved and, beginning narrow, opens into a larger area according to, #1 Placement within the structure... and #2 the atmospheric condition required to optimize engine performance. Most fighter aircraft, the fastest aircraft, are critically dependent on engine air flow. the faster the rate of speed the more critical it is to control the flow of air into the inlet. Engines can operate poorly from too much air just as they can from very little air. I noticed that several individuals were desiring to remove the Busa inlet screens. I have seen a few comments regarding FOD (foreign object damage) prevention, etc. I do not believe that the screens on the front of the Busa have a whole lot to do with preventing any types of ingestion into the inlet tract. The screen holes are much too big to prevent most large bugs (grasshoppers, moths, etc.) from entering. As well, the screens are much too weak to prevent a bird from really screwing up things inside the inlet tract, in the highly unlikely event that a bird gets hit by a bike (ever notice how fast brids get out of the way??? excepting those stupid pidgeons...). In any case, I believe the screens are there to set-up (if you will) the optimum atmospheric condition for the airbox to operate properly. Take your hand and flatten it out. Now turn it sideways to the ground and barely spread your fingers apart. Now quickly move your hand thru the air. You may notice a build up of air against your hand and, as the air moves thru your fingers and around your hand, the air speeds up tremendously. If you cannot feel it try it at slow speed sticking your hand out the window of a car. As I explain the following concept please try to remember that the engine is constantly demanding air from the airbox, at varying rates. I believe that the Busa inlet screens allow the air to build up in front of the nose of the bike. This build up of air causes the air to slow (of course) and the air pressure drops. As the air moves thru the curvature of the inlet tract (opening into the airbox) the air speeds up dramatically, causing the air pressure to rise dramatically. Once air is dumped into the airbox, the air again slows but due to constant feed from the inlet tract the air pressure remains high. As engine RPM increases, and higher demand for air increases, the air inside the airbox feeds the engine. However, the pressure in the airbox drops because its being used. That is probably why the engineers put those nifty little velocity stacks in the way of the cylinders. Something has to help keep the air pressure optimum, for optimum engine performance. If the pressure in the airbox drops too much, then the engine performance suffers greatly. It would seem that removing the inlet screens would not hurt air flow, but remember... the proper pressure going into the air box depends on the proper atmospheric condition going into the inlet... at all speeds. At higher air speeds no one would argue that there is plenty of air being shoved into the inlet tract, right? However, the design of any fast moving object means that all frontal structure be faired (hence the name "fairings") to cause smooth air flow. Notice the the very front of the Busa fairing? The head light pokes way out there! The headlight builds up air against it, just like the inlet screens do. As the bike breaks thru the wind the air as speeds up past the headlight and, depending on how fast you are going, the majority of the air could bypass the inlet all together. Thats when those inlet screens really do their job of creating that low pressure atmosphere in front, so that the inlets can speed up air flow to the airbox, so that the airbox can properly feed the engine. Remove those screens and you may end up suffering your engine's performance at low and almost certainly at high speeds. Check out the Brock racing website. They have an airbox mod for the Busa, but only if the engine is a 200+ horsepower engine. Under 200 hp, Brock recommends leaving the air tract (inlets, box and all) the way it was built. For me, that was mere confirmation of what I suspected regarding the Busa's air inlet system. Anyway, the decision is ultimately the responsibility of each rider... I guess its a matter of "show" or "go". I will choose go every time. Have a great day all, and thanks for letting me bend your ear.
