The guy from Pittsburg Power says that when you have an aerodynamic truck with tucked away air filter housing, your engine gets a much warmer air than a conventional truck with 2 air breathers outside of the truck. They suggest installing a second air filter/housing (like the Ecolite made by Donaldson) to get more COOL air to the engine. Anyone did this on an aerodynamic truck? I have a 2004 International 9400 with 1 huge air filter/housing on the passenger side under the hood.

Here's an interesting quote from some past articles on power and performance I found on pittsburghpower.com

Meh, I'm beginning to really question this guys logic.

The air is being grabbed from the outside, how is this any different from a "classic" truck? They both grab it from the outside.

I don't see how the air filter unit inside the truck is going to make that huge of a difference. Besides, with a classic you have all the ducting under the hood anyways.

Until I see some testing (turbo inlet air temps) I don't believe it. The size and efficiency of the CAC has much much more to do with engine air inlet temps then where the filter is mounted...

Try touching your air filter housing (I bet it's next to the turbo) after a day's long drive. If it's hot, the air filter is hot too, and it acts like a heating element of a stove when filtering the incoming air. What's wrong with this logic?

I'm only guessing on this but I don't think really cool air effects engine performance that much.

The reason I say this is you can do a technique like strip mining and reducing the air line from 12" to 6" to 3" to 1 1/2". Increasing the velocity of air reduces it's temperature by a great deal.

As an example. Take a front steer tire fresh off a truck with the inside air temp at 150 degrees. Take the needle valve out of the valve stem so the air comes out. It will be about 0 degrees and form ice balls.

The piping will also be hot, if that logic holds true. Yes the outside might be a little warm on ONE side, but the filter doesn't touch much of the filter housing.

Like I said, turbo inlet temps, has to be tested. And the CAC makes much more difference.

Hm, I should try this trick on a hot day, instead of running the A/C

The temp that matters is entering the engine from the intake. A scan tool will display this if you want see if it can be improved on. The air leaving the turbo can be upwards of 300 degrees F.

I'm pretty skeptical of most claims of aftermarket products & additives. It seems to me that the engine manufacturer would have to approve the truck oem's installation in the chassis.....

As for the air being cool coming out the valve stem thats the basic principle of refrigeration.........lowering the pressure on something lowers the temperature. Freon is under pressure till it hits the expansion valve (or orifice tube as the case maybe) where the pressure is reduced which lowers the temperature.

I finally got a response from CAT Call Center and the verdict is I don't need more air.

Here's my original question.

And their reply.

Any time you can get cooler,denser air that is a good thing. That has been proven a million times. I don't agree with everything Bruce has to say but he is right on this topic. If I'm not mistaken the 9400 series picks up air at the grille but runs it through a passage in the top of the hood over the engine and then goes into the actual housing which is still over the engine. So I would say there is enough time to heat the intake air noticeably. If you think any truck mfg hasn't cut corners on fuel economy/power to save a few bucks for themselves I could sell you a bridge or two.