dana70

I have a 93 D250 CTD with a 4" exhaust, now I want to take the next step before I increase the adjustments at my pump.

1. Does anyone have any great suggestions for lessening the restriction on my air intake filtration system?
2. Is the K&N kit worth anything?
3. Is there a kit for bringing air in thru a hood scoop?
4. How much boost is good boost with lo restriction on the intake and a 4" exhaust?

wannadiesel

Here is my setup. It's a BHAF, two 45 degree elbows, and a piece of 4" aluminum tubing. I don't like oiled cotton filters unless there isn't a big enough paper filter available. Paper filters better.

Monty

I second "wannadiesel's" setup. Ive been running mine like that for well over a year, except mine has had a K&N on for 100k worry free miles. The intake piping and Old Smoky mount is the best setup ive seen so far for the 1st gens.

dana70

Dave, I think that I have seen your photo of your air box before and I'm interested in it, Thanx. What is a "BHAF" and where would I come by one and does it include all the elbows and such? Or, is this a home made goodie?

wannadiesel

A BHAF is an air filter that is about the size of the whole stock air box. Big Honkin' Air Filter, BHAF for short. Part #'s can be found in the "tech facts" section. I got the 45 degree rubber elbows, intake clamps, and 4" aluminum tubing from Airflow Systems. You could use PVC pipe or exhaust pipe, too. You need about 13" of pipe/tubing. What looks like an air box in the pic is actually an Old Smoky BHAF mount. It's a very well engineered mount and drip shield, made of a sheet of aluminum diamond plate. Unfortunately Old Smoky is no longer making the mounts, he did post that he would make the plans available, but I don't know if that has happened.

dana70

Thanks Dave, I will procede in that direction, much appreciated!