Semi's and Ecomodding

[bgd73]

once a torque curve for a given fuel gets what it wants... a trailer skirt for a diesel turbo seems quite silly. The conventional front end designs do help the most, the rest of airstream is just going to get thrashed anyway.
Its like putting a little wing on the space shuttle as it takes off vertical. the fuel just simply overwhelms the function. Little gas engines notice it, especially inlines, as they have a knifes edge torque curve and constant fiddling for bad design reasons on all of them...in contrast (I have joked of this several times) a 2700 pound subaru with a little boxer could care less about a roof rack opr radiator cover making a wall of the front end. Concerns for aerodynamics is a concern for enough power to overrule it casually...and it really can be. I ahve been growing up with trucking for over 30 years, from the 1970s horrible cbovers with 290hp to the 550hp common now..and ya know what? they use the same, but the 550 is much more casual with a bigger load. I learned to target other things (like lube) for cars and trucks, and if not enough, it needs a bigger engine to be casual, and then start saving. Today is goofier than ever, after carb standard disappeared. injection could do anyhting at any moment, the soft bodies of new make change invisibly. It is the concern for today and aero mods, I am certain.

[Christ]

FedEx uses belly-type trailers... the "belly" is what acts like the skirt... they figured out that they could load another few cubic feet of stuff in the trailer that way, and slightly lower it's center of gravity.

[SmallFry]

Originally Posted by vtec-e

I've seen a good few of those side skirts on trailers. I've also seen the front top corners of the box tapered down to match the deflector on the roof of the cab. Nice! But i've seen no rear end work done on anything yet.

ollie

I was told we have a test trailer too, with "flaps" that open up into a kinda' boattail -- as shown in pictures above. They said they have it rigged where it closes when stopped and opens in motion. In theory, the DOT cannot get companies for over length trailers because they close below a certain speed.

The guy that does all the testing also said that the side farrings are being looked into. They've found a rigid, yet flexible rubber material where they can bridge the side gap between cab and trailer, but also allowing it to turn up to a 90 degree angle, and it return to it's original placement afterward. We'll see.