robert78.5

How restrictive is stock air box? 2001, Is there anyway of opening up the air flow without replacing it?

Number47

i've read its good for 500hp but i might be mistakin

98.5Hotrod

I read a report on airboxes and the stocker will flow enough air to support 500hp.

HOHN

At what pressure drop? The flow a filter varies a LOT with the delta P across it.

The question is, how much flow do I need to to support X amount of power, and what will the delta P be at that flow?

If the delta P is less than atm pressure, you can make the HP that this flow amount will support.

JMO

98.5Hotrod

HOHN, I would love to understand what you said but ?

robert78.5

And where would I get a Delta P gauge??

Lil Dog

Its on the box.. That filter indicator is your delta P gauge.

As far as I am concerned, the stock box is good for a step stand. The brick filter is just begging for leakage all around the gasket and does leak. I tested mine way back and found the corners were leaking dirty air. BHAF or MHAF would fix that problem as you clamp right onto the filter. IMHO of course..

wcbcruzer

I agree with above. The stock airbox doesn't seal tight and often times sucks in dirt. You can try putting grease around the edges then closing the box but a BHAF is easier, better, and less messy.

67HotRod

I chopped the heck out of the stock air box with a K&N filter in it. I went with the bhaf and spool up is a bit quicker, runs a little cooler and cools off quicker. Dump the stock air box and get a BHAF!

robert78.5

Yes i was looking at the indicator and figured if it was drawing too hard that that would mean it was restricting. I guess i like to tinker around with truck for best performance.

fiveology

Delta P = change in pressure, come on who doesn't know that???

offroad

What is a MHAF?

Lil Dog

There was a post a few months ago about a guy that sourced an MHAF, or medium honkin air filter. It had a shroud on it and he just cut it open to create a heat shield. I can't seem to locate the thread..

high bid

Search for "cheese hole" or take a hole saw and cut/drill some holes on the bottom side(pre-filter intake) of the stock air box. It improves the cfm flow rate some but nothing compared to the bhaf. Many ideas on here but check out Amsoil dry universal air filters...about $70.