airbox mods

[jkern]

i am about to start modifting my truck somewhat(JVD TE, gauges on order, injectors next) anyhow, it seems to me that the truck would need to breathe better. i am familer with the pscotty system, but why can't i just drill some large holes on the unfiltered area of the stock airbox for better flow? (this way the air to the turbo will still be filtered. ) has anyone tried this? any success?


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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, and a bunch of other little things!

 

[MMiles]

Jeremy,
I recall reading some posts about this about a year or so ago, but I can't remember what the verdict was. You might try a search on this topic. I had heard that it was a good idea to remove the plastic duct between the air box and the fender to provide a little more air. I also know of some owners using the cylindrical K&N air filter(I've forgotten the part number) attached directly to the rubber intake duct, and just set in place of the air box. Look around, theres a lot of info on the K&N's, P-Air, and other methods owners have devised. Hope you can find your answer. Good Luck!

 

[sport bike]

Remove the air horn and drill a 4" hole in the back side of the air box.

 

[Crazy Horse]

There is quite a bit of conversation back in the archives on 9/5/99,Wheels/K&N pertianing to your questions.

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2K Dodge 3500,4x4,SLT,Quad Cab,PR4 Red,Auto Trans,354's,Posi,Trailer TowPack,3 Piece Auto Ventshade Hood Protector,"BEEFED" up Factory Camper Pack{No Airbags},Factory Fogs,Rear Slider,Rancho 9000's,Rhino Spray In Liner,Smitty Built Nerf Bars,Alpine 60x4 Watt CD Player,Lance Cabover Camper,BD Plug n Power,EGT Guage,And Enjoying The Ride.

2K Dodge 2500 SLT RC LB PB3 Blue
99 Dodge 1500 SLT/Sport RC SB Solor Yellow {Her Truck}

 

[jkern]

ok, guys thanks for the info, but i am slight confused on one aspect. i am a fairly mechanical minded individual, and do all my own work to my vehicles, but why the sweeper hose? why not just leave the hole open? this bewilders me a bit!!

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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, and a bunch of other little things!

 

[Chad Sheets]

Leave which hole open?

 

[illflem]

The idea behind the hose to the firewall into the vent intake cowl is that the aerodynamics of the truck force air into this area. You are thus getting cooler air forced into the air box. If you just drill holes into the airbox you are drawing in hot under hood air. I never thought of tiring it without a hose,if you do make sure to attach large mesh screen over the airbox and over the firewall hole. Mice love making nests in the airbox,and if they can get into the vent cowl they will likely make nests in your vent system. No need to worry if you live in a concrete city.

 

[jkern]

ok, that makes sense to me now. i did plan on putting some type of screen over the hole that i was gonna drill. i think that i am going to modify my own air box rather than spend all that $$$$ for something that i can produce the same performance numbers for just a little time and effort.

thanks

BOMBing material on order #ad
#ad


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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, and a bunch of other little things!

 

[rhoads]

Didn't read all the replies,but having posted on this subject-------- take a 3/4 hole drill and you can put 4-5 holes on the dirty side (eng side-lower) of the air box. this has served me well. I wouldnt cut a big- single 4" hole.

 

[Chris N5CWM]

The short duct that goes between the airbox
and fender is oval shaped, somewhat like a
cone with an open end. It is not only there
to connect the airbox and fender, it is also
designed to muffle the turbo whistle. Take
it out and you will notice what I mean. As
for the cone shape, by removing it there is
more area for the airbox to take in air. So
what if some of it is mixed with warm air
under the hood. The other very effective
"turbo muffler" is the factory pleated paper
air filter. Replace it with a K&N or better
yet an Amsoil air filter.



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'01 3500 QC 4x4 SLT, Dk. Garnet Red, tan interior.
Cummins ETC, 5-speed, 3. 54 anti-spin; Line-X
Auto Meter boost and pyro
gauges on A-pillar; Valentine One radar detector
May the Boost be With You!

 

[sport bike]

For you mildly bomb trucks,just remove the air horn. That wont work for you highly bomb truckers. You,ll have to drill some holes. It took a 4" hole to fix the air problem on my truck. You might not need that much.

 

[Chad Sheets]

Guys, warm air is the way to go! This isn't a gasser. Look at big rigs. That big air cleaner on the fender allows CLEAN air to be pulled into the system, has nothing to do with cool air at all. In the winter time there is a flap that can be switched over so only warm air from under the hood is used to feed the diesel. These engines run the best with intake air between 60-90 degrees, and yes I have seen it proven in controlled tests.

I never have agreed with the different "ram air" system for a diesel. I think I described it as "Pi**ing down a waterfall and thinking you are going to speed it up. " That turbo is cranking out Rpm's between 60,000 and 80,000 Ram's. Regardless of how fast you drive, you aint gonna ram enough air anyplace to make it speed past the turbine in the turbo.

Will you decrease EGT's? YES, if that's your goal! Why wouldn't you? After all, you allowed for cooler air to enter into the system, which also lowers temps in the combustion process, producing less power. If EGT's are a problem due to so much added fuel, get a bigger turbine compressor.

Now does this "ram air" deal bother you when its sunny and 80 out? No. Because the air is going to stay between that perfect 60-90 degree mark regardless of where it comes from, rammed in or sucked in. Now put that ram air system to work when the flakes are flying and you are hindering the process of combustion by introducing frigid air into the intake system. There are even some intake systems way up north that draw intake air directly off the exhaust pipe in order to get the intake air to a good temp. Another neat trick they do is run copper tubes into the fuel tank that have hot engine coolant running through them to keep the fuel from gelling up. I asked if they ever had one of those tubes split/crack/break, and the guy said never ever. Kind of a neat idea I think. If you guys have a "ram air" system, and its COLD where you're at, ditch it until winter is over and put the stock box in so you can get some halfway warm air for your beast.


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Always ready to help!
2000 2500 Red Sport quad cab, 4x4, K&N, DDI's, straight piped, boost, pyro and fuel pressure gages, Hot Power Edge, mean looking set of 33. 5" tires, Snap On diamond tool box, Marine Corps window sticker, Semper Fi!

1972 340 Cuda'. Original tripple Black, 340 car w/air. Good clean car, super stock springs, Weld Prostars, shaker hood, strong 340 with a 727/4000 stahl, 4. 56... . Bombs away!
NRA Life Member. http://www.geocities.com/chadsheets

 

[Chad Sheets]

It wasnt copper, I think it was brass now that I think about it. At any rate, still a neat idea regardless.

 

[Gonzo 1066]

I am not sure I understand why cool air is bad for a diesel engine?? Maybe at an idle or excessive cold - 30. The turbo charger warmes the intake air by compressing it (that is why we have a intercooler between the charger and the intake manifold) The cooler the intake air the denser it is. Watch your pyrometer on a hot dry day and you will see higher exaust temps. On my diesel tractor puller 40 psi on the intake will melt plastic wire loom! I have seen pullers pack the air cleaner can with dry ice to cool the charge air, I know what you are thinking -dry ice is carbon dixoide. But the cooling effect is worth it. cool is cool #ad
hot is not #ad


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1995 2500 5 spd bombed. 2001 ETH 3500 stock. 1972 1066 International Harvester 414 ci diesel pulling tractor.
GONZO

 

[illflem]

Click here for more

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95' 25004X4,AT,Driftwood,Banks Stinger,Warn fender flairs and running boards(Play truck)95 3500,5 speed,Driftwood,Banks&Phscotty,34,000 GCVW apple and tractor hauler(work truck)

 

[jkern]

in general cooler air is better for intake, because it is denser and thus has more oxygen content, which supports better combustion(more oxygen molocules as well as other gases per given area). i do agree that "ram air" type intakes have no real affect on a turbocharged engine, but cool air is the way to go for performance reasons!


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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, and a bunch of other little things!

 

[illflem]

I agree Robert,cooler is better. I don't think you can ever reach that 60°-90°mark at the intake with a turbo,heck 1° cooler and the grid heater would be on. After a long run with my 3500 on a mid 70s day the temp of the intake as measured with my infrared gizmo was 320°pre inter cooler 240°post,this is with a Psycotty installed at idle,EGT was at 400°. If you were to draw air from under the hood these temps would be at least 150°-200°higher. If you were drawing in 0°air the intake temp would still be 170°. I don't feel you could ever over cool the intake except maybe in a sub zero extended idle. Don't forget air that is compressed gets hotter. I will be installing a temp sensor on my intake manifold soon,then I'll have some temps when the truck is working not idling. I'll bet the only time the intake temp goes below 150°is for the first few minutes after startup on a subzero day.

 

[Dreher]

I have a 96 12V and I own a scanner that will measure intake air temp from the sensor via the PCM. Off the top of my head, most of the time running about 60 mph, the temp is around 70-90 depending on the ambient air temp. When I stop at a light for a minute or so, the temp usually rises to around 100-105.
It is about 28 deg here now and I just checked the intake air temp without running the engine and got 35 deg, so I believe the scanner is accurate. I haven't done any real documentation but these are the figures I can recall.

Bob

 

[David_VT]

Which scanner do you use. Maybe its time to spend a little cash on tools...

 

[sport bike]

Cooler is definitly better. If the out side air temp is 70,and my truck makes 53psi of boost. The inlet air temp is 280. (pre intercooler)