I did the air box drilling yesterday. 12 holes, 3 rows of 4 (1/2" diameter) were drilled on the inner part of the airbox base. It did gain noticeable boost. It maxes out just a touch over 10 psi now instead of 9-ish. Performance increase was noticable.

While I had the MAF/air intake parts off, I noticed some black residue around the two ports on the intake right around and just inside of the thottle body blades/flapper valves. I rotated them wide open, and didn't notice it too bad past there. It seemed to have SOME oil in it, but was mostly dried up gunk. I wiped it all off OK. Is this anything to worry about?? I did take 1 pic if you need to see it.
Thanks.....

 

What you saw was unwanted oil that has been pressurized out of the crankcase past the PCV valve. Most, if not all Ls have it. It is 'common' but not normal.

Many guys don't worry about it and it probably won't 'hurt' anything. Some(me included) think it can be one of the causes of detonation--with higher boost.

Dan

 

Im sure this is detailed somewhere, but does anyone have pics of the airbox mod? Im assuming the holes are drilled in the bottom of the box? Any problems with moisture getting in with that opened up?

Ive got the K & N, but couldnt get my seal to fit? It appeared to be quite different in size than the box top..any harm running it without the seal?


Thanks

 

Someone posted pix of it a month or so ago. If not, I can take mine off again and take this pictures. Basically, if you take the air filter out, look down on the bottom section of the air box standing in front of the truck. You will see a raised section near the middle. The holes want to be on the left side of the raised section, the side closest to the engine. Some people have added duct work for a ram air effect, others have moved the whole side, and several have drilled holes. Basically, this just gives the engine that much more air and with less restriction. Most people I have talked to have noticed about the same increase in boost that I did.

 

see

http://www.ncs-stl.com/Images/air1.jpg

http://www.ncs-stl.com/Images/air2.jpg

http://www.ncs-stl.com/Images/air3.jpg