Stock Air Box Mods

[C.MILLER]

I've searched all the previous posts I could on this topic, and would like to hear any more input you have before drilling any holes. I don't currently have an EGT problem but if I could get a little quicker spool-up from the turbo I'd drill the holes necessary. My dealer thinks the Psycotty unit could void certain aspects of my warranty, so I'll pass on this mod for now. The thread on running a shop vac hose from a hole in the cowl to a hole in the filtered side of the airbox sounds like a good idea. The hole/holes in the backside of the airbox are a little more discrete, so I'm not to worried about warranty issues on this. Would this spool-up the turbo quicker?? Thanks in advance!!

Chris

------------------
00' White 3500 SLT QC 4x4,Leather, 4sp. auto, 3. 55ax, Banks Powerpack, Putco's Master Boss Boards,RS9000 Shocks/RS5000 Stabilizer

 

[Alan Reagan]

You don't mean the filtered side for the holes do you? That would be putting unfiltered air into the system. Anyway, I saw one at the SETDR get together in Atlanta two weeks ago. He had drilled on the back side of the filter box at the same level as the current intake hole. I've been looking at this including contacting Donaldson filters about a solution to get more are while still getting adequate filtering. Can't find a solution. I think that drilling will give more air but you are still dealing with the filter. A K&N in the airbox will breath better but then you have the argument of what might be going through it. My 98 had a K&N for 10,000 miles before I pulled it after finding residue in the turbo intake. My 01 has the stock filter for now. Don't drill on the filtered side unless you plan on filtering the air.

------------------
2001 HO 6 spd 2500, 4. 10 LSD, Towing Package, Electric Brakes, SPA EGT/Boost Gauges, Fog Lights, Real Backup Lights, Molded Running Boards

 

[C.MILLER]

Yes, I did mean the lower portion of the air box (unfiltered side). Thanks for the heads-up!!

Chris

 

[Alan Reagan]

I received an email from the guy at SETDR. He indicated that it did help with his problem. Larger injectors and 4 inch exhaust needed more air . He said that drilling the backside helped #ad
. As always, the identity of boys with the big toys at the SETDR will remain anonymous to protect the innocent.

 

[C.MILLER]

Alan,

What size of hole/holes are they drilling? Are they forcing the air in from the cowl to the box via a tube? If the holes are large(ie. 4. 5"), what are they using to drill/cut them? Thanks!!

Chris

 

[Todd T]

first if you are worried about the warranty i would have to say that drilling out the stock box would be worse. it doesnt filter very good now and to cut holes in it you would just be sucking in hot air from the engine bay, through an already crappy filter. if you are worried about the talk of water getting into it using the pyscotty air then block the cowl-vent holes above the hole in the firewall for it, it will still find plenty of air and nothing will drip into it. at least that way you will be getting fresh outside air and not pickig it up from the engine bay or off the road surface. Scott thought this thing out thouroughly before he introduced it to the world, and it is the best way going.



------------------
Todd,
2001 Q-cab SB 4x4 5spd 3. 55's, A pillar Boost/EGT,Jardines 4" turboback kit, and more to come...

 

[illflem]

Chris,I've been using the vac-hose,actually 3"RV holding tank dump hose,easier to work with for about a year. I may have invented it. It works excellent for keeping egts down and getting better air flow. It will be somewhat nosier in the cab at high boost. Ran into a friend of mine at the auto parts yesterday,he was picking up a cone type K&N for his just purchased '97 PSD to add to someone else's version of a Psychotty air unit(PAU),put the PAU to shame. Much larger air opening and drew the air from the grill area. We both had hoods popped and when he saw the stock intake hole to the airbox he gasped,much smaller than the stock PSD. Said he could see why I had to do something about that. A guy pulled up with a '96 CTD and of course he had to come look at what we were doing. We popped his hood and his filter minder was about half way up with a K&N,said he wanted a PAU,but when he saw what I had done he changed his mind. He followed me back to my shop and we did the hose install,1/2 hour. Said he'll join TDR first thing if he ever gets a computer. This was the 7th one I've done,everyone has been happy.

 

[C.MILLER]

I definitely like the idea of pulling the air from outside the engine compartment. Thats why I've been liening toward ilflem's get-up. There was one other thread I read that addressed having unequalized pressure inside the box from inducting the air from the cowl. How much more air is inducted through the cowl as compared to the passenger side fender (where the fender flange inserts)? If this is indeed a problem, then cutting a hole to match the flow rate of the fender flanges intake should solve the problem of this pressure thing. The question is, what size of a hole would this be??

chris

 

[illflem]

Chris,that would be very difficult to figure,you would need a wind tunnel and smoke or some sort of air gauge. With flowing air,and water also, if you have a short distance of reduced "pipe" it will have little effect on flow volume. If this wasn't the case the small stock airbox hole wouldn't work at all. I know what you are saying about the unequal pressures,but wonder if it really matters.

 

[rob10858]

ive read some posts about removing the air horn into the breather. while trying to solve another engine compartment noise question, i took mine out today. i was concerned at first because it looks like the horn is designed to direct air into the breather. i figured that i would soon be putting it back in. while i saw no difference in performance or egts, i did hear a distincly different sound while accelerating and gearing down. does this mean that its breathing better or not as well? i know from my 96 that the horn was always coming loose and either not even connected to the breather, or halfway sucked in and def restricting airflow. it is logical that the more fresh air coming into the system the better, and that seems to be what the horn was designed for, but is really a pretty p. . s poor design from what ive experienced. on the other hand, with the air horn removed, how does the air find its way into the small breather hole, obviously its indirectly, and there are better ways, some more drastic than others, in the meantime im all ears.

------------------

 

[Fuzz]

Well here I go again. Guess I missed the how to on illflem's hose install. Would you mind explaining again. Appreciate it. If it's old stuff(or not)Email OK with me.
Fuzz

 

[illflem]

Fuzz,here you goI never posted pictures because you can't see the mod well without removeing the hood...

The reason any airbox mods will increase "noise" is because the turbo sound is traveling back up the air tube,though the filter and out where ever it's directed. Pulling the air though the fender wall is a good location for directing the sound away from the cab and I'm sure that was Dodge's intention. Going though the firewall into the vent intake is not the best,but is by no means obnoxious and it's close and easy. The best would be to draw air from near the grill,but you run into a space problem doing that. It's possible that the fender intake and airbox hole could be enlarged to provide the air flow the Cummins needs to run correctly,but I have never looked at that route myself. I think the fender chamber acually pulls air down from low near the rear of the tire.



[This message has been edited by illflem (edited 02-27-2001). ]

 

[Frank J. Lloyd]

Originally posted by Alan Reagan:
I received an email from the guy at SETDR. He indicated that it did help with his problem. Larger injectors and 4 inch exhaust needed more air . He said that drilling the backside helped #ad
. As always, the identity of boys with the big toys at the SETDR will remain anonymous to protect the innocent.

Are you talking about Outrider, the guy with the winch at the meeting? He is going to finish drilling a few more holes. He convinced me to do mine, my box looks like swiss cheese on the bottom side, with that and my stack, I can hardly force my EGTs to 1050. I did notice more sound but not necessarilly faster spool up.



------------------
2001 3500 4x4 H. O. 6 speed 4. 10, SLT, Cab and Chassis, 163" wheelbase western hauler stake bed, silencer ring AWOL, boost & pyro gauge, K&N, Geno's one touch oil valve, Cobra 29 bombed, Halogen backup lights, cargo bed loading area flood lights, 6" driving lights, underbed boxes, pacbrake, 5" stack and exhaust, straight!
ready to bomb
Big Red is ready to roll!

 

[C.MILLER]

Illflem,

Does your turbo spool up any faster now with your modification, or was the primary benefit in reduced EGT's? I think I'll give your method a try, I was mainly looking for a little quicker spool up, but reduced EGT's wouldn't hurt. Where did you get the drillbit for attacking the cowl? A spade bit for wood will probably work for the air box, but need something for that metal cowl.
How about that RV dump hose, preferrably new!!!!! Can you get this at a building supply store? Thanks.

Chris

 

[illflem]

Haven't noticed faster spool up nor more power,just lower egts which translates into more useable
power,don't need to back off as soon. Best thing to use for the hole is a hole saw,you can cut though the sheet metal in 30 seconds with one. Some rental yards carry them,if you have to buy one it will cost around $30. I keep cutting the hose off the one I use for my camper,only takes about 10" but now my camper hose is getting too short to be useable. Most RV dealers/supply carry the hose,but in 12' lengths,still under $10. You could also use 3" dryer vent hose from the hardware,they sell it by the foot,cost you a buck.

 

[C.MILLER]

Thanks for all for the replies. I never really thought about things in terms of "useable power", but that makes alot of sense to me. I think I'll gather up the items needed and do the install this weekend. Unless someone out there has a slick way to ram the air into the box from the front of the truck. Things Look pretty tight up there though.

Chris