Swiss cheese airbox?

[Hutchew]

Does it pay to swiss cheese the airbox? Looks to me like it's pretty restrictive just coming through the core support.

Anybody notice any real gains (more boost and/or lower egt's) by doing this?

 

[Bob Beauchaine]

When I had an accident in August of last year the body shop had to install a new airbox. The first thing I did was to "swiss cheeze" it and I can feel the old Cummins breathing better. Sort of like having a cold and all of a sudden breathing better. When you cut the holes you can feel it sucking air at an idle. It is noisier but I just turn the CD player up another notch. BTW it had no effect on my oil analysis readings over the past 3 years.

Happy trails

Bob

 

[Lil' Dog]

Scotty system??

Scotty and I are testing some systems on my rig and I will let you know how it turns out.



As for the Swiss Cheese. . NO WAY. . I only remove the inlet to the filter to get HOT AIR in the winter for warm up. In the summer our little intercoolers can't handle the higher temps out of the compressor. Get more air from outside and thats the ticket. One fellow here has trimmed his inlet and front facia to get ram air to his setup. . sounds like a good plan also.



IMHO



J-eh

 

[Excessive Force]

RAM AIR....

Hey guys,what i tried was to take air from the grille area through the hole that is between the radiator and the coolant reserve tank. Though primitive, (my first design) made from 2. 5" pvc pipe and hose, i noticed a drop of about 100 degrees in e. g. t. ,and a gain of about 2# boost !! I am going to make one that looks a little better now that i see the benefit.

 

[Midnite]

I actually just recently removed my airbox and am extremely happy with the results. I get slightly more turbo noise, maybe a 50 deg. drop in egt, and about a pound or two more boost at wot. I just pulled the airbox out and let the air filter rest in the same position. About the only thing I'm worried about is that it may bounce around a bit, although it doesn't appear that it's a problem so far after about 100 miles.



I think we may be talking about apples and oranges when comparing the air filters on 1st gens--at the very least, I'm almost certain I've read that the '92 uses a different air filter setup than the '93.



On my '92, the air filter is a cylinder, similar to the BHAF, but smaller in diameter, and mounted by the coolant overflow bottle on the passenger side at the front of the engine bay. In this position, I don't believe there's anything at all to worry about regarding drawing warmer underhood air, vs. cooler outside air. It's not like the front of our trucks is airtight, forcing air to be drawn from the rear over the hot exhaust manifold. Air, like anything else will take the path of least resistance (anyone here use woodstove?), and more of that air is going to come from the front especially when the truck is moving.



Mike

 

[Lil' Dog]

All the first gens are the same for air filters. The only diff is that the 89-91. 5's filters were nutted to the hose and lid instead of just set in there. I am using the K&N from my 89 in my 93, I just sealed off the hole for the bolt in the end of the filter.



J-eh

 

[CRWilliams]

Instead of swiss cheesing mine, I opened two square holes in the front side only of the box(the grill side) about 3X4 inches. I also noticed a couple of extra pounds of boost. And the exhaust brake sounds alot louder

 

[GeneH]

I think the biggest restriction affecting the intake is the exhaust system. Replace the crushed exhaust with a mandreal bent one and the engine will breath a lot better.



GeneH

92 350 4x4

 

[ScottB]

After installing my powerwagons I could get 30lbs of boost pretty easy and I would get some pressure cooker sounds. I was unhappy with my K&N so I got a Big Honken filter and it just clamps on the intake hose and lays in the location of the original air box. Works great lower egts a little and better boost. I dont get that funny pressure cooker noise much now.

 

[Hutchew]

Thanks for the input guys........

I really would have thought there would be more than 17 votes by now, though. Looks like opening it up is leading the pack... .....

 

[LRamey]

I went to the wrecking yard and snooped around until I found a 3" plastic air intake hose. I cut a 2 15/16" hole in the bottom front of my air box and pressed it in. Then I ran it up and around the battery and put it next to the radiator. I saw a 75 deg. drop in temp and only cost me $5. 00. If that's swiss cheese, then I'm for it!