Hi. My husband and I are new members and would appreciate any help we can get. Today Ray put a 90 elbow and K&N filter on the air intake and would like to know what keeps the K&N filter from getting wet when it rains. On 93 6.5TD

The hood, mostly.

Seriously, any exposed filter will get damp when not in an airbox, although it won't be too bad unless you're into creek-crossing.

A more serious issue is the fact that an open air filter in the engine compartment will pull in hot air. Turbos (by their design) make the air hotter when they compress the incoming air. Add these 2 things together, and your intake air will be VERY warm by the time it hits the engine. The computer senses this and, being programmed to inject just enough fuel for optimum combustion, knows that hot air is less dense and contains less oxygen ... it then reduces the amount of fuel the engine gets, which reduces your available power.

Which defeats the purpose of putting on the K&N in the first place.

Thanks for the info. I'm confused though. What is the purpose of removing the original airbox, if you have to put a new one around the K&N? What do you gain?

What year is your truck, MagnoliaT ? (it makes a difference in the answer, 'cause they have different airboxes)

While your truck is mechanically injected, the air filter situation is similar to the EFI 6.5, and causes much pro\con discussion on replacement\rework.

The factory airbox does the best job of filtering the cooler intake air pulled thru the fender duct.

Most install the cone-type almost-a-filter in order to hear the turbo spool-up, but few then have the engine oil analyzed periodically to determine any increase in the level of silicates, which is dirt.

While the hood does help keep the rain away, the open filter is exposed to anything pumped thru the radiator by that big fan on the front of the engine.

This will result in necessity for increased frequency of replacement, compared to the enclosed oem filter, if protecting the engine is the ultimate goal.

I had the same setup, in the winter it was fine being open in engine compartment... but now that it is warming up I put the filter in the box with stock intake. I am in the process right now of trying to make a big tube from airbox to turbo

sigh... can't read. Ignore my dumb question.

The 'flat-panel' filter that came with the stock airbox doesn't work too good for air volume, and the 'snorkle' inside the fender further restricts how much air your engine can get. THAT's why your hubby changed it.

gmctd is right, though (like THAT's surprising), in that the K&N tends to let more grit through. It helps lots when it's in a box, pulling air from the fender. Lots of guys on here have pictures... search for 'air box'.

Our truck is a 1993 ck3500 4wd dually. Sorry we're new to this whole computer thing and haven't figured everything out yet. When I figure out how to include all the info in my signature line...I will.

if your husband is handy, he should build a new box around that K&N filter that pulls the air through the stock hole. Then remove the snorkel that goes through the fender. There's a how to in the FAQ thread.

My husband is alot more than handy. He did remove the snorkel first and we spent alot of time researching the FAQ last night. Can you tell us why some places sell the induction kit with no box? Just want to be sure doing this mod right.

My husband is alot more than handy. He did remove the snorkel first and we spent alot of time researching the FAQ last night. Can you tell us why some places sell the induction kit with no box? Just want to be sure doing this mod right.
There's controversy on these trucks whether it's better to have better airflow or cooler air. Nobody is really sure. The best solution is to build a box around a large filter.

No controversy, at all - better to have more cool air flow, not more hot air flow

The oem airbox draws air in thru the duct in the fender from the front of the truck, where air is much cooler that that pulled thru the radiator by the fan.

Vendors are driven by economics - most anyone will spend a little on a paper cone filter, but only a few will spring for the whole package, incl a fabricated air box that doesn't fit and seal, properly.

Most do not seal well enough to justify the 1000 to 2000 % outlay, and none seal as well as the oem '98 airbox with it's round filter, which is vented thru the fender.

'Course, ya cain't hear the turbo with the good one, and them cone filters sure look professional, like on ricky bobby's car.

No controversy, at all - better to have more cool air flow, not more hot air flow

The oem airbox draws air in thru the duct in the fender from the front of the truck, where air is much cooler that that pulled thru the radiator by the fan.

Vendors are driven by economics - most anyone will spend a little on a paper cone filter, but only a few will spring for the whole package, incl a fabricated air box that doesn't fit and seal, properly.

Most do not seal well enough to justify the 1000 to 2000 % outlay, and none seal as well as the oem '98 airbox with its round filter, which is vented thru the fender.

I ran tests with a temp probe in all sorts of places under the hood, both at idle and on the road at speed. Factory fender has the coolest air by far, round filter air box is more then sufficient for stock and the OEM filter is superior for filtering out dirt.

Yep - maybe them factory engineers really are smarter than the guy under the tree, with his hood up, eh?

The flat panel filter on your 93 is rated at 100cfm, the rating on the newer round filters is 250cfm. The best case is updating to the new style round air cleaner housing connected to the fender with a paper filter. Look for one at your local auto wreckers. I have made the change on my 93 and feel it was a worth while upgrade. I would also suggest getting a replacement to the horrible exhaust downpipe on the 93's, mine was 50% squashed from factory. In some cases factory engineers aren't so smart.

Pictures of the downpipe.

http://www.dieselplace.com/forum/showthread.php?t=73715

Yep - maybe them factory engineers really are smarter than the guy under the tree, with his hood up, eh?

Sarge,

Can't I just modify it and feel good about myself, regardless of the truth? I'm putting on traction bars and flourescent bulbs under the truck tonight! Or maybe I'll just take my hydrocodone and hope my back gets better. Or maybe I already took my hydrocodone...it's becoming a fog....

Hey - my kinda guy, Maj - I'll be over to help ya soon's I get all the tree sap off my truck...............

Hey, just want to say thanks so much to everyone who gave us info on the airbox mod. Ray has another question for Tracy. He noticed in your signature line that you have a home made mechanical boost controller and would like to know how you do that.

FYI - the design of that down pipe was good - when the vendor was chosen cross-border is where the practical realization of the design went south, as it were................

There's controversy on these trucks whether it's better to have better airflow or cooler air. Nobody is really sure. The best solution is to build a box around a large filter.
Excuse me, I'M sure. :rolleyes: Cool air is MUCH more important than the tiny bit of increased airflow from a cone filter.

How about both, a round h/o filter in a round box, works on mine, turbo whistles on upper end; but not as pronounced on bottom end when in the cab with windows up;

Fairly decent spool up sounds with windows down at all speeds, oil samples all have come back low silica content, I'm running a oiled Amsoil round filter.

FYI - the design of that down pipe was good - when the vendor was chosen cross-border is where the practical realization of the design went south, as it were................


That would explain the first several thousand but not several years of production, ultimately the responcibility rests in the hands of the engineers to make sure what they spec. to thier out sourceing partners is what ends up on the vehicle. This time the engineers can't blame the bean counters since it costs more to mess up a perfectly good piece of pipe than to leave it alone. The engineers admitted to making a mistake on the size of the flat panel airfilter by making the round filter a few years later that has 2.5 X the filter area. But I suppose the flat panel filter would flow all the air that the downpipe, and snorkel in the fender would flow, opps I guess it was all engineered to work together as a engineering cluster f***.

Engineers get many things right but they also get many things wrong, after all its the reason why many of us hang out here, we wouldn't have anything to talk about if they got everything right on the 6.5, guess there would be CR and whats he up to.LOL

Agree and disagree - 6.5TD power output was deliberately limited by the factory, in any manner necessary.

Note no oem application of a charge-air cooler - they put one in the same body style for the DMax - why none for the 6.5?

Note the proposed 19:1 pistons never made it to the production floor, even after the '97 cooling upgrades proved functional - whyzzat?

The turbo was a patch to catch up with Dodge and Ford - the 6.5 was sop to the consumer, already accustomed to the 6.2 as a Diesel 'powerhouse' - the DMax was the end solution on the drawing boards.

Took the DOD to force a workable solution to all the 6.5TD problems, and the results are just now showing up for public consumption.

The 'recalibrated' downpipe was the least of the factory's worries while rolling 6.5TD's off the assembly line(s).

Are you 100% sure the 19:1's never made production? I'm still baffled as to why a certain vendor gave me $100 pop for my old pistons on the original engine?

No part number has ever been found for those 19:1 editions - part number is same for all 6.5's.

Be easy to tell - increased dimension to cyl deck or dished crown

Even Monty Python and Indiana Jones have not been able to find those holey grails...............

It just hit me, i think that was for the stock pistons that came in the new shortblock.

Very definite savings for him, then, even if without the ringsets

Heres an intake for you all, Factory round filter w/filter box. Close off the fender inlet and go through the hood with a HMMWV style pre-filter. You will have to ENGINEER the connection so the hood will still open good. Then, between the filter and the turbo you will want an aftermarket u turn into the turbo. Or go ram air.

tinderbox, whats the hmmwv pre filter look like? is it like the external air filter on a heavy duty truck? I've often laid awake nights trying to figure a way of putting a HD truck-style air filter on the outside of my fender without looking retarded. I bet it wouldn't be too hard to fabricate, but it would look pretty stupid I bet. Unless a lot of people starting doing it and everyone got used to it. I just don't want to be first.
I have seen far too many so called cold air intakes that do nothing more than suck hot underhood air. I've considered some different ways to get outside air but havent tried anything yet. One idea was to run a 3 inch flex pipe from the side of the factory airbox over to the firewall, where it would draw cold air out of the cowl area below the wipers. Should be cooler, turbulent air, but I don't know if and when it might have a sort of low pressure area where the air going over the hood would have a negative impact on it. A small Jeep style scoop would probably work to direct air into the cowl. I was a little leery of what the rain and snow would do so I never attempted it.
My other idea is to cut the fender side of the stock airbox off, then cut the inner fender out to the same size, and put it back together with a rubber weatherstrip seal. I don't know how much more air is to be had inside the fender. I also thought about doing the same thing, only with the top of the filter box sealed to the hood, then louvering the hood directly over the filter box. Again, would be a problem with rain and snow.

You can get a picture of a HMMWV or hummer (military version) on any internet search site. look for the piece of rounded lid looking thing in front of the passanger side windshield. It would go on the hood it-self and you would need it to separate from the duct UNDER the hood so you can still raise the hood. I'll atempt it this summer if I can stay out of Baghdad long enough. Ill send pics if it works.:) :chevy:

One idea was to run a 3 inch flex pipe from the side of the factory airbox [...]

I don't know how much more air is to be had inside the fender.


Hmm. Does anyone know how well the airflow through the fender is? The air must be coming from somwhere at the front, since there`s a plastic snorkel behind the blinker/DRL on the passenger side (remove that snorkel ...).

But the fender isn`t exactly optimized for flowing air. Maybe it would make for an improvement routing said 3" flex pipe through the fender to the front (letting aside that it may not fit through there), without exposing the open end of the pipe directly to the front of the truck?

Such a pipe may provide a smoother path for the air than the inside of the fender, thus improving airflow. I won`t care much to seal the pipe to the inlet of the airbox, shouldn`t be necessary ... It won`t let in too much dirt/water/snow then.

What do you think?


PS:

Hmm, maybe the front end of the pipe could come out in front of the radiator, maybe easy to do on mine since the AC cooler is removed. There should be some air pressure there when the truck is moving, and if the end of the pipe just comes out of the fender and goes around the corner so that it`s at an angle of about 90 degrees to the front plane, it would be hidden behind the lights and not draw too much dirt?

Seems like I have to check that out once the weather is better :)

detroitdan, take a look at my garage for a inexpensive way to get more cool air to your engine. Your truck might have a different hook-up at the stock air box but if you still have the snorkel in the passenger fender and use the set-up I made you will get twice the air to your engine. PM me if you're interested for more info. Good luck.

Hey, just want to say thanks so much to everyone who gave us info on the airbox mod. Ray has another question for Tracy. He noticed in your signature line that you have a home made mechanical boost controller and would like to know how you do that.


Sorry for not responding to your post earlier I must have missed it, just reread the tread and noticed it. The 92/93 6.5's have a mechanical/spring operated wastegate. factory seemed to be limited to 4psi boost. There are several ways to increase boost, the easiest (my first attempt and works well) is just add a helper spring to the factory spring, I used a tension spring 9/16 dia. by 6" long(had to cut to 4.5") with .072 wire dia. it is a Dynaline spring part # 24231. It will give you 8psi boost if you hook it from the boost lever to the waste gate spring braket. You shouldn't mess with the boost without boost gauge and having the stock downpipe changed. Your exhaust gas temps may go to high and will not see much hp increase because of exhaust bottleneck.

Outher ways are with Heath Diesels mechanical boost controler, and Banks also has a way of doing it (I will Private Message the links since they are non vendor sponsors). My present boost contoller looks something between the two. I went with a extended boost lever like Banks 2"(I used a 3") from the factory 1" then used a braket mounted to the turbo (similar to factory and Heath's)with a adjustable spring like Heath's.