Faired in trailer hitch with bottom of car

Ok, perhaps we are not supposed to have a trailer hitch, but I needed it. After a trip downstate I noticed it was harder to get into the top 50's mpg. than the previous trip.

So today, I dug out some plenum material from our furnace install, cut it into a 24x in think 20'' piece. Drilled holes for plastic clips and connected the forward section to the fairing plastic under the car, keeping the flange that was on the metal part for rigidity and bent it to enter the existing join of plastic. The aft part covered the hitch nicely and I just used four very heavy furnace type plastic wraps and tightened them to the hitch.

Now I have a completely faired trailer hitch out of the air flow and looks like it is designed into the car. The only give away in looking under is of course the galvanized metal does not match.

Tomorrow, I will foam this full and fair outward so no air turmoil will be apparent.

To put to rest wonderment if this will make a difference, it will. I made a home built airplane which I flew with a small motor for a number of years, it would max out at about 55-60 mph. At one point I tore off the landing gear which had a cross tube between the wheels and replaced this with a bent spring, similar to normal landing gear. My speed when flying went up to and exceeded 80 mph. which was of course too fast for the wings, but it would get there, a major drag having things disrupt air flow.

 

I am adding this as today I finished the job. I took a can of spray in urethane foam after molding one end with cardboard and just foamed in the shape as well as closing the other end to prevent wind tearing at the metal. Also the foam tends to bridge between the metal add on and the plastic that is there.

The last little trick was the several inches of square trailer hitch tubing that I dared not foam on as it approached the exhaust and it was outside of factory fairing. So I merely bent a metal piece and place over this into an airfoil like the struts on an airplane, riveting the trailing edge. A quick coat of black paint and the job was done.

 

I will get a couple tomorrow. Take a few days to get out as I need to get into town to upload however.

I wanted to wait for MPG figures before posting more. Wife went to Traverse City yesterday and back and we are back up to 61 mpg and today just touring around I maintained the same mileage. Before without the fairing, the best was about 56 or less, so this seems to be working. Car only has a few thousand miles on it however, so it should do better later.:rockon: