hey guys, i just recently purchased an FD, I have yet to pick it up, but one thing i noticed, the car's only mods are full exhaust(dp included) and the intake airbox has been replaced with two K&N filters. So when revving the engine, below 2800rpm, there is a hose that makes this loud noise, I searched it up and realised that it is the airpump...the hose is no longer hooked up to the airbox as there is no stock airbox...it's just there...i'm guessing this is no good? I didn't check to see if it pumps air OUT or IN...I don't want to remove it just yet...

just wondering if it's safe sitting there...

I have to drive it two hours home when I go to pick it up, so I just wanna make sure this is ok to do so...or should I cover it up or something...

I searched but the only thing I could find was information on removing the air pump...

 

It would likely be the hose the air pump draws air in through. It should ideally have a filter on it. At least on an FC, air pump air can make its way into the intake manifold during deceleration via the anti-afterburn valve. I'm not positive, but an FD may have this valve as well. The factory service manual is free on the web (links in the 3rd gen FAQ), so now would be a good time to get acquainted with things under the hood.

 

What you are hearing is the relief line for the airpump. The stock airbox has sort of a silencer built in to mute that sound. When using an aftermarket (non-stock) intake, you need to do something to mute the noise. The easiest thing to do is to use a cap on the outlet with 3-4 smaller holes drilled in it. Here's an old picture of my engine bay with it:

 

ahhh ok, i'll take a look when I pick up the car!


RotaryRocket88: yes I plan to look over the service manual and familiarize myself with the vehicle. I tend to spend hours on reading up on anything I can find...this being my first rotary powered vehicle, i'm very excited!