Air Cleaner

[TURBOLICKER]

Hi guys, I know some may say this subject has had the crap beat out of it but even after reading all the info I still need some input! I read the article by A2000RICH that indicates @ 28" a stock set up through filter will flow 445 cfm. Question is what would a 3.8 with a 6057 turbo at 17 psi boost be pulling at 5500 rpm? If it doesn't need any more than 445 cfm a stock set-up works fine right? Trying to ascertain more specifically when it becomes a restriction or impediment in performance. Next question would be if a K&N filter would change these flow numbers. If you look at the stock hose and elbow to the air cleaner they are approx. 3", the opening in the stock housing to the snorkel is also a flattened 3" hole. So whats the difference if you change to a 3" steel pipe? The size has remained basically the same. The factory air cleaner housing has the plastic snorkel running through the rad support for fresh air and also sheilds the filter from hot engine air. I just figure until you pull a vacuum through any 3" tube you are not creating pressure drop. So wouldn't we just need to know the flow through a specific length of 3" tube to figure this out? Any help would be awesome! Thanks!

 

[UNGN]

Air molecules don't just look at the lowest flowing orifice in the system and ignore the other restrictions. Air that has to flow through two 445 CFM orifices in a 3" pipe is going to flow less and have more pressure drop than one with only one 445 CFM orifice. Even a system with a 445 CFM orifice and a 600 CFM orifice, won't flow as well as one with a single 445 CFM orifice, so the goal would be to eliminate ALL of the restrictions.

There is lots of badness in the Factory airbox from an aiflow perspective. I don't like the flow into the box, the way the air has to do an unaided 180 through the filter, the box hold down nut support right in the airflow and MAF screen right at the exit of the 90 degree elbow.

An unmodifued stock airbox is a restriction on a 14 second car. If you bolt one onto a 10 seconds car, it will instantly be transformed into a 12 second car.

I have a Airbox mod in the Fabrication section that deals with all of the badness, and allow a stock appearing airbox to run deep into the 11's, if not faster:

 

[TURBOLICKER]

Awesome write up and great idea! Are you still using factory corrugated tube from elbow to turbo? its hard to see.

 

[UNGN]

Yes, the factory flex hose.

My car ran 11.53@118 on Drag radials with a TA49, 36# injectors and a 100% long block thru the modded Air cleaner.

When the car was stock, I went 13.8 thru the stock airbox, but dropped to low 13's switching to a Cone K&N with no other changes. It eats a ton of HP, even on a stock car.