Class 8 Trucks

[Big Dave]

There has been a ton of work done on this. The sheer diversity of howtrailrs are used defeats any "one size fits all" mods.

I do know this: leave your underhood air filters alone. They are the optimum setup.

[SmartTrucker]

Originally Posted by Johnny Mullet

What kind of trucks? Kenworth W900 or something more aero like the Kenworth T2000?

We have some W900's in the fleet nothing aero like the T2000. Most of our trucks sport a classic truck look like those of the longnose kenworth W900's. The freightliner columbia models are probably are most aerodynamic trucks in the fleet which isn't saying a whole lot.

Our Columbia models are like this one but the sleepers are smaller and the exhausts are not behind the sleeper but just behind the doors.

[SmartTrucker]

Originally Posted by Big Dave

There has been a ton of work done on this. The sheer diversity of howtrailrs are used defeats any "one size fits all" mods.

I do know this: leave your underhood air filters alone. They are the optimum setup.

Yeah it's virtually impossible to really make our flatbed trailers aero friendly. I think all I can do with the trailers is look to eliminate uneeded weight and find a good cheap tire with the least amount of flexing.


About the underhood air filters though it just doesn't seem optimum. When the trucks are in the yard I'll try to get a photo or two of what I'm talking about. They seem to be in a location that would most likely pull in hot air which can't help our power situation out any (this is on the columbia models)

[jamesqf]

Originally Posted by SmartTrucker

About the underhood air filters though it just doesn't seem optimum. When the trucks are in the yard I'll try to get a photo or two of what I'm talking about. They seem to be in a location that would most likely pull in hot air which can't help our power situation out any (this is on the columbia models)

I don't know if this carries over to diesels at all, but in my Insight I get better fuel economy with warm intake air - 100-130F, as opposed to whatever comes in from the outside. I think it allows the ECU to run a leaner mixture.

Of course economy is not the same as power - on long flat stretches the Insight doesn't need much power to maintain speed, and I suppose with the trucks it'd depend on how it's geared. So maybe a flapper valve to pull in cold outside air when power is needed (like on hills), or warm air when cruising on the flat.

[johnmyster]

You're going to have a hard time "fooling" a diesel computer into running a leaner mix - at least based on intake air temp.

The whole reason why your gas engine pulls fuel is in order to cool things off in the combustion chamber and prevent precombustion that a "hot mix" could be succeptible to. Um, precombustion isn't an issue in diesels. Forget about it.

Plus, why would you ever want to intake warmer air on a TURBOCHARGED AND INTERCOOLED engine? By the time you go through all that processing, you're not going to affect precharge air temperature anyway.

By the way, most gas engines NOT ONLY pull fuel when they see high intake temps, but they will also pull out timing. Um, power and efficiency (power per fuel) go down when this happens. It will vary in magnitude from computer to computer, but you're trying to convince your computer to use less gas. In the end, the computer will correct based on O2 sensor readings. I'm pretty convinced warm air is a placebo effect. Didn't work on my vehicle.

If you better understand what goes on inside your computer, you can better understand what to do outside. Warm air does not make a combustion process more efficient. It makes it worse. Maybe your computer does something funny, but the basics of Carnot/Rankine cycle dictate that a cooler charge/sink temp is more efficient at harvesting the heat energy from the source. Always.

[SmartTrucker]

Yes diesels are different then gasoline engines when you're talking about intake air cool should be a good thing on diesels.

also I forgot to link a photo of a freightliner columbia. This one isn't ours but it's similar it has a larger sleeper though and the exhaust is behind the sleeper like ours should be.

http://ppgmedia.buysell.com/ppgphoto...04-display.jpg

[SmartTrucker]

also...........now I know there is those things out there that are too good to be true and maybe this is and if I was one truck I'd likely stay away from an item like this................. but what do you all think of fuel preporators?

I'm waiting for one to come in to test and well could be an absolute waste of cash or worse cost me more but if it works I could save a lot with it when you multiply it by a fleet worth of trucks. There seems to be some legitimate testing behind it. Has anyone ever toyed with one of these?

http://www.pureflowtechnologies.com/FP200C.htm

[FunkSkunk]

Weird my pics didn't attach on my original post... so here they are.

[FunkSkunk]

few more...

[FunkSkunk]

That crazy cab design is by this guy named Colani, he does all kinds of smooth designs like that, just google him. He's got a killer mustache too!! lol