About the Airbox Flapper

The problem with these types of mods is most can not show any hard evidence that they accomplish the intended goal. I would suggest that if any one can show me a dyno chart of any improvement caused by this modification and only this modification I will be out in my shed sawing and cutting.

I will concede that it may be of some value in conjunction with other mods, but I doubt that alone it increases anything other than intake noise.

I'd say removing the entire lid and the door would make excess intake noise. I can't say mine's really any louder than normal with that flapper gone.

You're right, SheWolf.
Doing the flapper elimination made no increase in intake noise that I could detect.
I did try the whole airbox top removed, and that was loud enough to annoy me.

2goose wrote:

The problem with these types of mods is most can not show any hard evidence that they accomplish the intended goal. I would suggest that if any one can show me a dyno chart of any improvement caused by this modification and only this modification I will be out in my shed sawing and cutting.

I will concede that it may be of some value in conjunction with other mods, but I doubt that alone it increases anything other than intake noise.

I believe you're on the right track.
Doing just the flapper elimination alone and expecting something is kinda' like expecting new window panes alone to transform the ol' house that's got tons of old paint flaking off of it.
You need to add a fuel programmer and get rid of the stock muffler.

My opinion is if you refuse to buy those things, don't bother with it.
The sad part of doing that is the bike will remain plugged-up and run like a snail.

weakest link theory

YZEtc wrote:

You're right, SheWolf.
Doing the flapper elimination made no increase in intake noise that I could detect.
I did try the whole airbox top removed, and that was loud enough to annoy me.

2goose wrote:

The problem with these types of mods is most can not show any hard evidence that they accomplish the intended goal. I would suggest that if any one can show me a dyno chart of any improvement caused by this modification and only this modification I will be out in my shed sawing and cutting.

I will concede that it may be of some value in conjunction with other mods, but I doubt that alone it increases anything other than intake noise.

I believe you're on the right track.
Doing just the flapper elimination alone and expecting something is kinda' like expecting new window panes alone to transform the ol' house that's got tons of old paint flaking off of it.
You need to add a fuel programmer and get rid of the stock muffler.

My opinion is if you refuse to buy those things, don't bother with it.
The sad part of doing that is the bike will remain plugged-up and run like a snail.

i agree 100%
Like you say, "if i had to return the bike back to stock, I would sell it"

I've got the FMF powerbomb, FMF Q4 and FMF programmer. If I do the airbox mod will I need to adjust the programmer?

It wouldn't hurt to account for the larger amounts of air you'll be getting through the intake.

gatorfan wrote:

I've got the FMF powerbomb, FMF Q4 and FMF programmer. If I do the airbox mod will I need to adjust the programmer?

Is there a greater risk of water getting into the engine after the airbox mod with the bike verticle. I go through some pretty deep water sometimes.

I think that depends on what kind of air box mod you do. If you just rip off the top and leave it like that... well, yeah, I would venture to guess you'd be more likely to get some water in there. If you just gut the air box and leave the top scoop intact (minus the guts), I would say you're no more likely to get water in there than stock. The intake points to the rear of the bike, so if you have water coming in that way, you're most likely pretty submerged anyway

gatorfan wrote:

Is there a greater risk of water getting into the engine after the airbox mod with the bike verticle. I go through some pretty deep water sometimes.