Drilling out Air box

[andycook]

OK, I have been wondering about this for a while now. What is the benefit/purpose to drilling the holes in the airbox on a CIS system? Does it help anything in particular? Is there a caculation to how big and how many holes? I already have a pop-off valve. Thanks.

[Hetmann]

You can cut holes on the cover and even go without. Do not drill holes in the airbox itself or you will be buying a new one.

[sammyg2]

IMO it is a complete waste of time with no benefit.
Some folks have shortened the snorkel and reported that it "might" make a slight difference.

[andycook]

I understand about only doing the cover, and I also see our host is selling a modified airbox cover. I am just curious what it is supposed to gain? Or, what does it hurt?

[jluetjen]

I have yet to see any indication that the airbox on a CIS car is in any way the restriction to air going into the engine. That distinction appears to go to the airflow meter in the CIS system. For the most part, in a non-turbo'd car, changes upstream or downstream of that meter won't have a very big affect on airflow.

I may be wrong, but I've been looking for the slightest reason to believe otherwise as long as I've been on this BBS and haven't found it yet.

What putting holes in the cover may do is make the induction noise a little louder, which to many people is an improvement. Even then it's nothing compared to the sound that you get from carbs or MFI.

[andycook]

So basically then it would be more of a sound issue than anything? I have carbs waiting to go on, but until I get to that, I was just looking for other ideas.

[poorsha]

I think it's kind of cheesy

[andycook]

OK, guess it's time to sit back and focus on getting my carbs on. I was just wondering what the purpose was. Thanks for the input guys.