Ram Air Ducting

 
     

To help improve the Dodge Dakota aerodynamics, a front air dam has been added with openings for ram air ducting on the Project Sidewinder diesel sport truck.

The rules in our Bonneville class allow any size front air dam as long as it doesn't project forward of the bumper line. Our custom air dam, made in-house at Banks, also includes ram air ducts.
 

A new front air dam not only reduces aerodynamic drag, it also provides an ideal location for ram air ducting to feed the turbocharger.

The custom front air dam made at Banks Engineering for Project Sidewinder serves a dual purpose. The first, of course, is to improve the aerodynamics of the pickup by limiting the amount of air that can get under it. The underside of any vehicle, with no bellypans, is a very "dirty" area. The air dam improves aerodynamics significantly by pushing air to the sides instead of underneath the truck.

But, since the engine needs to ingest air—the more the better—why push all this air out of the way, when we can "swallow" some of it and feed it to the engine? That's the second thing our custom air dam does. Two carefully contoured inlet openings scoop up air and direct it to the turbocharger inlet. Not only is the cooler, outside air denser than hot air under the hood, but also the air pressure at the front of the truck provides a free supercharging effect at high speeds. At Bonneville, the primary hindrance to speed is wind drag. The vehicle is literally pushing air. This wind drag increases with the square of speed (that is, exponentially). The air pressure at the front of the truck is equal to the wind drag, and it gets significant at high speed. This pressure then "rams" the air into these scoops, creating pressure in the ducting even before it gets to the turbocharger. Air drag is bad. But ram air ducting is good.

On the street, the ram air ducting will not be used since it provides no filtering of the incoming air. Instead, the ram air ducts will be removed and an air intake with a conical K&N filter will be positioned immediately behind the right ram air opening in the front air dam. A sheetmetal rain shield prevents rain from soaking the filter through the ram air opening.
 
 
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Clay modeling was used to mock up the front air dam prior to making a fiberglass mold.
The buck for our new fiberglass air dam was formed and carved in clay by Banks "modeler" Sean Torres.
The original round openings in the air dam were enlarged to a rectangular shape for greater airflow.
Here Sean is adding a second layer of clay to the buck to change the original round openings to the final rectangular shape.
A mold was used to make several front air dams for Project Sidewinder‰s Bonneville runs
Once the clay buck is finished, a fiberglass female mold is laid up over it.
Duplicates of the Bonneville air dam were made in case damage should occur during a high-speed run on the Salt Flats.
Then the fiberglass parts are pulled from the mold. We're making at least one extra air dam in case one gets crunched.
Ram air ducting collects cool pressurized air from both sides of the air dam and channels it to the turbocharger inlet.
Behind the air dam, this ducting collects the high-pressure air and feeds it to the turbo.
Ram air ducting supplies cool pressurized air to the turbocharger inlet on the Cummins common-rail fuel injection diesel for increased torque and horsepower. The ram air ducting on Project Sidewinder benefits the turbo diesel engine for increased diesel performance at the Bonneville Salt Flats.
Sean first modeled these parts in clay, then two-part molds were made over each. This ducting was laid up in lightweight carbon fiber instead of fiberglass.
The ducting enters the Sidewinder engine compartment on the right side. An extension routes the air to the turbocharger.
From this outlet, the high-pressure ducted air is fed to the turbocharger inlet by large-diameter aluminum tubing.
On the street, the ram air ducting is not used. Instead, cool air is picked up immediately behind the right ram air opening in the front air dam. A conical K&N air filter is used.
 A conical K&N air filter positioned behind the front air dam handles the street filtering of cool air to the turbocharger. The inner fenderwell and a steetmetal rain shield in front of the filter help keep it dry.