White02Sport

Greetings, all. I'm getting ready to make my heatshield and pick up my BHAF, and a question came up that I can't answer even with doing a search.

My question is this: what's the ID of the stock air intake tube? There is mention of using 4" exhaust tubing to adapt the BHAF to the stock tube, but it appears to be a bigger diameter. Will a section of 4" exhaust pipe be sufficient? I'm using a CarQuest filter (#87790), which has an ID of 4-1/8" roughly, so I don't imagine it'll give me too much hassle by squeezing it down a bit.
I haven't measured the OD of the filter, but I would imagine it's close to 4-1/2" or better, and I haven't checked to see if the filter will squeeze into the intake tube. Maybe I don't need the exhaust pipe at all.


Thanks for your input.

jrs_dodge_diesel

The BHAF will fit with no modification to the intake tube. I put a BHAF on my '01 real easy. Stock airbox out, BHAF set in place, slip the tube on the BHAF and tighten her down. I don't have any measurements but the BHAF will fit to the stock intake tube.

White02Sport

I had heard of different filter diameters, where it would attach to the intake tube, which is partly why I had asked.

I'm picking the filter up tonight, and the pre-filter should be here by Thursday, so I might try to install the filter by itself tonight and build the shield this weekend.

Moose10

Nope, 4" pipe will not work with the stock intake tube, it'll be too small in diameter. I tried that with mine....was going to paint it red and put the filterminder in it, but there is no way you can compress the stock tube enough to have a good seal on a 4" piece of pipe (the piece between my muffler & resonator) which went missing one day after a sawzall attacked it.
The BHAF does fit the stock air tube fine though. I plan on getting a pvc reducer to put in between so I can mount the filterminder in it.

White02Sport

Excellent replies. Thank you all for your time.

DZLPWR

On my truck i used a piece of 4" pvc with a piece of 3.5" slid into the 4". Homemade but it fits great. Kind of like a crude reducer. Your intk. tube dia. could be different since its a newer model, as well as your filter. Just a quick idea.

moparguy

From the guy who discovered and coined "BHAF"; use the 4" muffler pipe as a stiffner that you slide inside the BHAF to prevent the clamp that compresses the filter to turbo hose from deforming the connection, allowing unfiltered air to enter at the BHAF to turbo hose connection.

I had this happen back in August 02. Many have not had this happen, but why take the chance? 2 or 3" of thin wall pipe is all you need.

Good luck, RJR

atc250r

I used a coupler for plastic drain pipe. Not heavy PVC but the thin stuff you use for storm drains. Got it at the local hardware store, your best bet is to bring the intake boot into the store and find what matches up best. However, I didn't use the paper BHAF, I found one on K&N's site that is an oval shaped conical filter. It is really big and works perfect with the BHAF shield. If you want the K&N PN I can look at the filter and see if it's on there.

John

White02Sport

I put it in this morning before I left for work. The filter slid right onto the hose, just as advertised. What bums me out the most is the condition of the stock filter and that P.O.S. filter minder. What a joke! That filter was almost complely clogged with junk, and the filter minder was still at 100%. I don't think it ever moved in 42k miles.

Anyway, the turbo sounds GREAT! I'm seriously gonna have some fun with that.

dodgeman01

I know mu filterminder worked. I remember when I first did my injectors and cam plate. on the drive there the filter minder was at the top on 100% when I got home it was sucked all the way down. I knew then that the Stock air filter would not flow enough. put the replacement K&N on and it still pulled down about half way. cut some holes in the box and that stopped than. Switched to the BHAF and never put the minder back on.
DM01

scuzman00

Just a note, I drilled a hole in the end plate of the BHAF and stuck my filter minder into it. It was a super tight fit, but it worked. A side note to those who may want to try this is to drill up through the filter casing so that no small plastic particles can find their way into the pleats of the filter. After you drill it, use a shop vac to remove any wayward particles that the drill bit pushes into the clean side of the filter.

Gary