Air filter and engine problem

[spoonito]

Ok, I changed the air filters yesterday to the K&N filters. Took me forever to finally get all the bolts in and tightened down. Well, to my questions and concerns.

The top end never really felt all too strong to me, but I always figured that's how the car was (some cars are super fast but feel like you're going slow). Well when I was taking the driver's side airbox cover off (LHD) I noticed that the bottom 2 bolts weren't seat/torqued all the way down. In fact they were a bit loose. So what do I find? My filter on that side is dirty on both sides of the filter. In fact the back side was dirtier than the "filtering" side. So I'm assuming that at higher speeds, the "ram" air from the side scoop is pushing the air box open slightly causing a loss in air getting to the engine and letting dirt particles into that side. The passenger side was snugged down completely so that back side was clean as it should be.

I also have a question about the "channel" on the airbow that the rubber part of the filter sits into. There was melted plastic in part of the channel that looks to be from when the airbox was casted. It's pretty sizable, probably 3/8" high and 1" long. It wouldn't let the filter seat correctly in the channel, so I dremeled it out to make it flat. I hope that was the correct thing to do, as the filter sits in the channel better now.

The car has almost 21k miles on it now, but who knows when the filters were changed to this last set, I doubt they are the original filters as the bolts looked like they were taken off before and the passenger side filter was pretty clean. My question is, how much damage (if any) was done to the engine/turbo from it being like that.

So now with the K&N filters and everyting seated properly and all the bolts tightened properly I took it out for a test drive. The engine feels a more responsive (even my brother said the same thing) and the butt dyno says its a little faster. BTW I do love the noises the intake makes now.

[gmendoza]

It's hard to tell. My biggest concern would be dirt damaging the turbo blades.