Im thinking of making a poor mans cold air intake until i become rich magically ha. I was wondering what the size of the end of inlet tube is so i know what size cone filter to buy.

Has anyone else did this? suggest it or against it? Why pay 200 for a tube thats already there?

 

A lot of people here run the napa 6637 filter on there trucks which if i remember correctly has a four inch inlet on it. There are different manufactures of the 6637 out there put i don't know the part number off the top of my head. I am running the napa 6637 filter, i just used a 90 degree fitting and made a housing out of diamond plate aluminum, not the prettiest but it was cheap and helped performance of the truck
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Are you looking for something like this ...



If so you can make it yourself with NAPA 6637 filter but you will have to find the elbow locally, like mine. Save yourself some grief and call Clay at riffraff and he has a kit to do what you want.

Riffraff Diesel

 

You beat me to it my 1 minute .. darn I hate when that happens.

 

I found out the specs of that filter AND other part makes and models that are equivalent.

Specs. are OD-8.5", ID-4.0"(outlet), HGT-12.38"

Fram CA6818 Donaldson ECB085011, B085011, Fleetguard AH19002, Hastings AF2329, Cummins 2912986, 3912020, 3912986, Tippecanoe B08-511 Wix 46637, Napa 6637, Luberfiner LAF2531, LAF2533, Baldwin PA2818, PA2820, Fleetrite AHR-81141, AC A1474C, Air Refiner ARM-08-5011, Big A 94637, Carquest 88637

 

If you want to go really cheap, just grind off the sides of your stock air cleaner lid. I just did it on mine, and definitely felt the difference. Eventually I plan on going the 6637 route, but my filter is still good, and this cost me only 10 minutes of my time. My engine is basically stock, so I think I've gotten all the air the stock downpipe can handle for now.

 

I just installed the Fram CA6818 air filter its exactly the same as NAPA's 6637, there made by the same company and the Fram filter was on hand and half the price as NAPA's so i went that route.. I took pictures as i went along and moded up a peice of 4" 90/ white PCV pipe, i had to grind down the end that goes into the air filter to get it in, its tight but holds up very well... i did all this for under $50 bucks. I hope these pictures help out anyone wanting to do this them self's , its easy and done under the one beer status

 

Now, living far away from all the options and availability that most of you enjoy having at your fingertips, I have found this thread to be real useful. Thanks for the good pics, too. (yep, worth a 1000 words)
Having just dealt with Clay at RiffRaff, I wouldn't hesitate to call him again .

 

napa fiters are made by wix iirc, not fram, but still more airflow

 

Sometimes you can sell the intact stock box on ebay for around $100.

I've been thinking of the AMSOIL EaAU4095 airfilter. For a stock truck, hell, even a stock truck w/ a chip the 6637 will work great, but if you want to really make some power with bigger injectors and stuff, well, IMO even the 6637 isn't enough. Most people don't agree with me, but most people don't crunch the numbers or look at the data sheets either. Here's some info on the breed of filter it is:
http://www.amsoil.com/lit/databulletins/g2241.pdf
Travis has alot of info on it.

What is Hell's Gate?

 

Don't run PVC for very long if you can help it... it WILL distort with heat and let dust into the intake. I built a Tymar replica intake for my truck, cost me about $120 but I already had a piece of 4" exhaust tubing with the right bend in it. You can source the parts from AirFlo Systems.

 

Grind the sides off the lid? Got pics of what you did?

 

i'll keep my eyes open on the pvc, thanks for the heads up