I made it out of the metal used to make one-piece rain gutters.

I guess I could unfold it and make some templates if anyone's interested.

 

I always wondered what a scoop like they used on newer Camaros or older tubo Z's would look. They're low profile, but I'm not sure how you'd keep the rain out.

 

Bigragu, I can't quite figure out why you cut that hole you talked about. The intake opening sits just at the top edge of the bumper, so I suppose you might gain a little more forced induction at speed. But without a scoop of some sort I can't imagine how it could be of much effect in front of a turbo. There doesn't appear to me to be any restriction there to begin with. You say "what a difference," so I'd be curious to know how you measure that effect, or exactly what you mean by that? Are you seeing increased boost at some point after this mod? Please explain.

 

The stock hole is way too small. Some guys swiss cheese the stock box but that pulles hot air from the engine compartment. Make's perfect sense to enlarge the pass through and use the stock airbox, except I can't get rid of my BHAF!

 

OK, so basically we are talking about just enlarging the rectangular tube and the hole in behind the bumper it connects to ...

 

This is how I get the cold air into my airbox.




It is then plumbed through a cutout in the inner panel and connected with 4" aluminized tube.




Made a sheetmetal manifold to connect it into the airbox.



Besides getting cold dense air into the engine, I get around 3-5 pounds of free boost @70 MPH
With my foot off the throttle it boost gauge registers pressure.

The rest of the project is in my gallery.
Jim

 

I can,t remeber who sells them but I actually thought about doing the same thing. I did a Google and came up with some real nice looking chrome and polished stainless airfilter housings. The price was more than I was willing to bear. $600-$750 without the plumbing. Then I thought about triyng to keep it on the side of the truck during hunting season and all the flack I would get from the guys at work about my "Big Rig Starter Kit". I wimpped out on that one.
Have you looked at the air intake for the Hummer? It draws from a mushroom near the hood hinge.

 

Nice set-up.

On page four of your gallery, the bottom right two pictures, what is that black plastic looking gizmo??

What part does it play??

Did you use a standard size filter??

What happens in heavy rain??

Birds?? Big bugs??

Thanks.

 

I like that, Jim.

I would assume that you can use an Old Smokey mount for a BHAF with a scoop like that, correct?

How much room did you have behind the grill to run that ducting? Was that (4"?) ducting the most that could fit, or could you swing some 5-inch?

 

The plastic part is the actual air scoop, I went to Banks Engineering here in Azusa Ca. and was looking for something I could use, they let me look around in the shop and I found this one, It is used on the Ram Air Power Pack system they sold for big motorhomes.
I think I paid about $40.00 for it.



Notice the hole at the rear of the scoop; this is to bypass the water from rain and whatever else you pick up so it is not ingested. It seems to work.





Here is how I mounted it below the bumper so it is in the air stream.
I know some are going to comment but I have a K&N filter in the air box, it is the one I got with the Banks Power Pack system, it was included with the exhaust system.
All of my air plumbing goes down behind the core support, not behind the grille so you could use as large of a duct as you could stuff in there.

As far as rain, I have never had any problems but my concern is since my truck is low I am worried about sucking up water from going through a puddle but so far I have hit some deep ones and I am ok. I am going to design a valve so I can close it off from the ram air and open it up under the hood but I am still in the thinking stages at this point. I was thinking about designing a rotary valve into the sheetmetel part on the air box that would rotate 1/4 turn to open and close air passages kind of like a big Ortega valve for us in the know. It could be pull cable actuated.



Begle1
As long as you could drop your duct down from your airbox, you could use as large of a duct you could fit is the space.



This is looking from the front of the truck under the bumper. I had to cut out a notch in the inner fender panel so the duct would not rub on anything.



If you wanted to make one similar to this, you would not need to use the same scoop, you could use a 4" ABS sewer pipe elbow with a short section of 4" ABS to connect to duct to.
All of the sheetmetel I used is standard HVAC duct I got from my HVAC supplier but Home Depot also has it.

Jim

 

I am not talking about the hole that the OEM filterbox inlet duct passes thru;Ileft that alone. It is the exterior "trim" piece in front of that that one would see from outside of the truck staring towards the front of the grill, passenger side. If you pulled off your chrome grille you will see what I mean. being a sheetmetal worker by trade I could have easily fabbed up a new inlet duct and went from my proposed opening all the way to the filter box, but I wanted that gap in between in case of a heavy down pour. As far as what I meant by "what a difference" I felt it at my right foot, from a dead stop to WOT. It is the same concept with what the Ford PSD owners are doing to their 7.3's. The factory designs in both the Ford and our trucks is made to "pull" air from the underside of the truck. I feel it is better to ram/force feed the air right into your filter, and what better way is there than directly from in front of the truck?
Having spent 20+ years in the field designing and installing commercial HVAC systems, and now teaching HVAC, I must say I am quite knowledgable in removing any form of restriction to increase air flow, and with a diesel, the more air, the better! I really should learn how to post pics...my fault...sorry!

 

That amazes me, you get boost with no fuel at 70 even with that big ol' hole in the back of the scoop.
Now you have me working on a stock pot variation in my head so I can keep my beloved BHAF!
Mark

 

I have the hole closed with a plug since it never rains here in Southern California.


I have been thinking about a scoop made of fiberglass that would go under the front bumper in the style of the ones on a F-16 Falcon or a A-6 Intruder.
Or even a Pro Stock hood scoop cut off and flipped upside down. Do you get the idea?

 

I have been looking at the sheet metal floor vents at HomeDepot. There are some fairly narrow yet wide ones that have smooth transitions. A person could even lay fiberglass over one to spiff it up and make it stronger... hmmmmm
Thanks Jim!
Mark

 

Lots of good ideas here. I went ahead and tried to combine the best of what I've seen and came up with what I'm gonna call the "Bigragu cold air stock intake upgrade." I'll post some pics tomorrow after I finish putting it back together.

I like Jim's idea to use a scoop to gain positive pressure on the intake. Like he said: "free boost." But I didn't like the low mounting, could be an issue in a flooded street or stream crossing. Opening up that front fascia like Bigragu talked about seemed like a no-brainer after I took it apart and looked at it for a few minutes. But integrating that into a fully sealed scoop affair was a little tricky. I was amazed at how sloppy the fit on the stock parts was. There was like a half inch opening between the box and air tube.

Anyway, I opened up the hole in the rad support about a half inch on either side, expanded the connecting tube to match and seal on both ends, and connected it to the new scoop hole, building on Bigragu's idea. Now there's nothing but cold ram air entering my stock box through a larger intake. Pics tomorrow!