Quote:
|
Originally Posted by enigmamdw
Yes the sound will improve even more the more you open up the box.
There is a negligable performance gain by opening the airbox more than say half of the lid.
opening the lid more than that will have no effect what-so-ever (cept sound)
the engine can only suck so much air at a time and while you can't really open in up "too much" you will not benefit performance-wise by opening the box up too much further. I had at one time the actually numbers and all the logic behind that saved somewhere but I have since then crashed two HD's so I no longer have that info handy....I'll look around for it.
|
Same with me. I had a link to a site that did an excellent job of explaining where the real performance gains came from by opening the lid. I do remember that any performance gain had more to do with decreasing turbulence inside the box than it did with gross airflow gains by virtue of a larger hole... Something called the Helmholtz theory. With a closed lid, you get shock-waves from the intake pulses bouncing off the top of the box which would cause a resistance to the incoming air. This limited how much air could actually get into the throttle bodies at high RMPs. It made perfect sense when I read it. True, the engine will only suck in as much air as it can. The trick with the open lid is to eliminate air turbulence in the box so max air goes straight in. It has been several years since I made this mod myself, but in my personal experience I do remember feeling an improvement. My first hard ride with the open box, I ripped the throttle to wide open and it went right into the rev limiter. It spun up scary fast compared to how it performed before the lid was opened. It was in keeping with the theory. The performance gains will only really be seen at high RPM and with how fast the engine can get there... Oh yeah, it sounds wicked cool too!