Posted December 08, 2003 - 11:06 PM
The intake/grab handle, in the right hand plastic, measures 23.6cm2 + all the leaky areas around the rear plastics.
Now if the 39mm dia. carb. measures 11.94cm2, why do you need to cut everything open when there is already more than double the airflow available than the size of the carbs venturi?
Without an air filter installed, I think it would help opening up the box a little, otherwise I think the difference is negligible. I’m thinking the most restrictive thing is the air-filter.
Does any of this make any sense?
Posted December 09, 2003 - 12:44 AM
Posted December 09, 2003 - 10:09 PM
Posted December 10, 2003 - 06:27 AM
When the air box is open it allows more air for on demand use. The air doesn't first have to be drawn into the airbox, then through the carb. Now as the carb starts to draw air, air will back fill into the airbox but it just shortens the time by a little.
Beyond that when the airbox is opened up your only drawing through one small opening, the carb, instead of a 2. Basically when the airbox isn't open its like a long straw.
Now I could be wrong about how all this works but the bottom line is that guys with open airboxs notice an improvement in performance.
Posted December 10, 2003 - 08:58 AM
Posted December 10, 2003 - 09:40 AM
Posted December 11, 2003 - 05:25 PM
Posted December 11, 2003 - 06:46 PM
Posted December 13, 2003 - 02:40 PM
Posted December 19, 2003 - 10:41 PM
Posted December 20, 2003 - 01:06 AM
You get 1hp by removing the top of the airbox.
You get 1hp more by also removing the seat.
However thare ware some dscution on TT before if the holes on the side of the airbox really help. They make big numbers on dynos, but when you move maybe some vacum is created????
Posted December 20, 2003 - 09:19 AM
My seat of the pants imression was that it may have rev'ed a bit freer at wide open, high rpm's, but definately made the low end bog worse, and felt rich on the bottom. I then removed the side cover and went for a short ride, and didn't notice any difference(except noise). Dropping the needle one position cleaned up some fo the bog, but power still felt a little soft down low. After one ride I bought a new air box lid, raised the needle back up, and all is well.(I did cut the lip down on top to clear the seat base better though, because, well, I just can't help it, I gotta screw with stuff )
Anyway, just my observations. I can't help but think the Yamaha engineers may have spent some time working on the best way to get air around the battery. I know air box resonance plays a big part in sport bike performance. Maybe some of that knowledge went into our bikes as well .
I don't doubt some you have had good luck with your mods, mine was a step in the wrong direction though.
Posted December 20, 2003 - 05:15 PM
Posted December 20, 2003 - 07:12 PM
Posted December 21, 2003 - 09:54 AM
Posted December 22, 2003 - 10:26 AM