I am thinking about doing part of the airbox mod and have a question. I'm not interesting in removing the resonator, or the so called Tuba (I don't think) but am seriously considering removing or modifying the so-called flapper (VAD) and/or the tray under the air filter, but can't find any info about this mod without removing the resonator.

Has anyone done either of these by itself, or know if there would be any negative effects of removing the flapper?

 

Removing the flapper is supposed to be part of the mod....but out of curiosity, why are you not planning on removing the tuba? The resonator, I can understand, but why not the tuba?
Also, the resonator is inside the front bumper (underneath the airbox). So to do the mod without removing the resonator...just leave it alone. They are two separate parts so doing this should not be a problem.

 

Well I don't really know anything about the tuba, maybe someone can give me some insight on it's purpose and reason for removal.

I really like info on the flapper, like are there any negative results from removing it, and how much will it help drivability, especially in first gear, and performance?

 

Removing these parts reduces the restrictions on airflow into the airbox. This means greater air flow, and greater airflow means more power. You're not gonna get a huge bump in power from this mod, but you will likely gain some power. It does sound nice though and free hp, is free hp, can't argue with that. There are not real drawbacks to this mod unless you count a nice intake growl as a drawback. The parts you are removing are mostly there for sound dampening, and they do that very well...so well that you really can't hear the engine at all, but a side effect is that they restrict airflow. Now then, with these parts removed the engine is not loud, but the growl is noticeable on acceleration, otherwise it's pretty much as quiet as it was when stock.

 

I am most interested in the flapper mod. I would like to leave the plastic part there and just remove the flap if possible, since it sticks out towards the side of the car a few inches I assume that would help keep cool air entering rather than hot from the engine.

Would I have to remove or plug the vacuum hoses for it?

 

I believe you just remove the vacuum hoses that are attached to the flapper and that's it. No need to plug anything for that mod......I think, it's been a good while since I've done one of these so I don't remember precisely.