There are only two photographs in this section: the first is the fittings that are bolted inside the front frame horns and penetrate the air dam, the second is the tow bar itself.
Tow Bar Fittings
Necessity is the Mother of Invention, so they say. My wife is not a racer and will support my activities to a certain extent. That includes driving the tow truck down the return road and picking me up after a run. I have observed many people towing their cars with tow ropes both to the starting line from the pits and then on the return raod back to the pits or impound area. Using a rope means that a driver must remain in the car for steering and stopping. And if that is me after a run in August, then something other than a tow rope had to be devised. I did not want to ride back in the sweltering sun...and it gets pretty hot at Bonneville in August especially when wearing a full fire safety suit (in my case a -20 level suit!). So I tinkered around with an idea for a while and decided on a tow bar. That meant I had to have some kind of attachment to the car frame rails. The photo shows what I came up with: simple bolt in fixtures that utilized some rod ends. I already had the threaded nut portion for the ends to screw into so this was a pretty easy idea to implement. I measured the distance from the frame rail to the air dam and cut pieces of angle iron. Then I clamped the nut into the angle and to the frame and marked everything. I moved the nut out a few tenths of an inch so it would protrued through the air dam when I drilled the hole for it. I fitted the pieces together sticking through the air dam and pronounced this to be a good method. I tacked the nuts for the rod ends in place and removed the air dam. I welded some thick plate to the inside of the angle so when I drilled it it would support threads for the attaching bolts. I placed the pieces in the fame rails and clamped them in place and drilled pilot holes through the frame and through the fittings. I removed them and drilled the frame for 3/8 inch diameter bolts and the fittings for a 3/8 inch coarse thread tap. I tapped the fittings then. The 3/8 inch bolts are grade 8 bolts in single shear. I reinstalled everything to see if it was good to go, then finally welded eveything in place...forever... I cleaned then and painted them a hammertone silver color as I do for most of my fabricated parts. One of the frontal views of the car with the air dam on shows them installed.
After I had the car attachments fabricated, it was on to making the tow bar itself. One of the things I had observed twas that cars that did use short tow bars invariably got salt from the tow car tires kicked onto it. I decided that I wanted a long tow bar to help remedy this. Tow speeds are limited to a maximum of 35 miles per hour so the tow bar did not have to meet any really stringent constraints. I had a piece of roll cage tubing, 1 5/8 inches in diameter and 0.134 wall thickness, so I decided to use a full stick of that. I think it is 8 feet long. I bought a trailer coupler for a 2 inch ball but I had to fabricate a "box" for the end of the tube to fit snugly inside the coupler. When this was welded in place, I used 2 - 7/16 grade 8 bolts through it to make sure that it did not come loose during a tow. On the car end, I bought some 1 inch square tubing, 16 gauge in thickness and made the cross bar and the rod end attachment fittings. This took a bit of cutting and grinding and welding, but was not a complex task. I purchased some pins and some small chain to keep everything attached to the main tow bar. Now I just have to get the tow bar out of the back of the truck, drop it onto the car ball end fittings, put 2 pins in, and the safety pins through them. The roll the car up to the trailer hitch on the truck, drop the coupler onto the ball and off I go...in the cool of the truck cab in the air conditioning! Like the other parts, I cleaned. primed and painted the tow bar in the same hammertone silver color.