best way to increase air intake on IDI turbo?
 

I though the best way would to be get an old trusty K&N air filter like ive always done for my cars, but it sounds like that isnt a good idea on these trucks due to the fact the truck wouldnt have any vaccum to close the CDR valve and it seems like id have an oily intake.

I just bought a stock air intake assembly, and bought a K&N filter for it i also bought a paper STP filter only because it was only a penny at autozone (dont ask why cause i dont know)

I always see guys saying you need to open the intake and exhaust to get more power, so my question is what is the best way to get more air with what i have (stock air box assembly)

On a non turbo, a free flowing air filter and fancy forced air intakes will make a niticable difference in power, on a turbo, no real difference. These things only wind up to 3300 rpm the turbo will pull all the air it needs. You might have a very sightly ( and I mean very slightly )quicker 0-60 time, but how often are you drag racing?

The only engines that really benefit from a free flowing air filter are n/a diesels and carbureted gassers. For turbo engines, no real difference, and for computer controlled engines, it's a moot point since the computers control the air fuel ratio no matter how freely the filter flows, but they look cool and sell like crazy. Most air intakes the restriction point at high rpm is not the surface area of the filter as much as the area of the intake to the housing. By the time the 80's rolled around, the auto engineers really did have those calculations pretty well ironed out.

Now if you want to let that turbo really do it's thing, rip that stock exhaust off and run 3" or better with a straight through big truck muffler, and that will alow that turbo to actualy see it's potential and give you the power where you need it in a truck, for pulling.

yeah i have straight pipes from the turbo back so im ok in that department
but as far as the air intake goes i should just leave it as the stock setup?

I have had very good luck with running my air intake in from the core support and using what I call a BHF (Big Honkin Filter) from Napa. (After doing much research on the KN filters I no longer use them in anything I drive.) I don't have the part # for the Napa filter right off hand but it is a slip on, cone shaped filter that slips over a 4" pipe. I ran the intake similar to the way Dave S. (Dave S. Pics) has done his with the exeption that I fabbed an air box at the core support to keep it totally separate from the engine compartment. (Similar to what is on a Superduty)

As far as air flow to your engine I use to use a simple method. First off, make sure you have a pyrometer installed. I can't stress that enough if you are running a turbo. From there, if you see black smoke in large quanities coming out of your exhaust upon accelleration you need to get more air to the engine. You want to see a small "haze" of black. Anything more and you are just wasting fuel. The more air you get to the engine the more fuel you can burn but be careful. If you get too much your EGT's will get to high. I wouldn't recommend maxing out your air/fuel but you can get it set to optimize your performance and economy.

The NAPA # for that filter is 6637, I don't remember the price, around $20, maybe a bit more!

just checked Napa Online ...

Air Filter - Industrial, Air Filter

Part : FIL 6637
Product Line : NAPA Filters
Price : $51.49

Would be well worth the money tho for the service it provides in getting a maximum airflow ...

Oh yeah ... http://www.napaonline.com/NOLViewer/...698&ShowPics=1
Gives the dimensions too ...

What you really don't want is to draw in hot air from under the hood.
A dirty or improperly installed CDR can cause problems (speaking from personal experience). However, as long as you do a reasonable install and keep it serviced (clean every other oil change and don't overfill your oil), I would think you would be fine.

Vacuum does nothing good for a diesel. Anyone think otherwise?

Since I am a boost hound and have done internal mods to stand high boost pressures, ram air to a turbo does make a difference in two ways.

First the air from in front of the radiator is cooler, so the EGT's go down and the engine has more power.
Second, the ram air turns any vacuum between the air filter and the turbo into positive pressure.
That means the turbo can produce more boost since it is working from pressure instead of having to overcome a vacuum to get air.

The difference I notice, since the vacuum is gone things like the rocker cover gaskets seep a bit of oil.

But when you are out there with a big load pulling a hill, who cares if the rocker covers are seeping a bit of oil.

Too bad it is so hard to find snorkel kits for the older rigs ... That seems like a good way to minimize the intake air temps ...

Hypermax "Air induction kit" is available for 83 - 94 F-250 diesel.