Building A Race Car Trailer Part 1

Sometimes we bucks-down racers spend all our money on the race car andthen have to borrow a trailer to get it to the track. This is an all toofamiliar scenario, so I sat down to devise a simple open trailer thatwill safely transport my beloved car at an economical cost. In thisfirst article, we'll cover the basic construction of the frame andrunning gear.

GETTING STARTED

The guidelines called for a 16-foot-long bed with adovetail rear to lessen the need for long or steep ramps. The objectivewas an open bed with runners on each side, because often I don't unloadthe car to change the oil and check for loose bolts. With this setup,you can also lie under the trailer and scan the bottom side of the carfor damage.

It is my belief that a trailer needs springs, two axles, andbrakes, although many are built without them. Keeping cost in mind,mobile-home axles work very well. In many parts of the country, they areabundant, but you should check with local agencies to make sure they arelegal to use in other applications. Several states have laws to theeffect that a mobile-home axle can be used only for its intended purposeon a mobile home. Most often, mobile-home axles are left intact by theinstallers.

The axles on this trailer were obtained by crawling under afriend's mobile home and cutting them out--with his permission, ofcourse. All the mobile-home axles I've encountered have a capacity of6,000 pounds or greater and have matching springs. That's 12,000 poundsof capacity for two axles, more than enough for a 3,000-pound car on a1,100-pound trailer. In choosing mobile-home axles, you will find somewith brakes. Get at least one of these if possible. You'll be glad youdid if you find yourself in a tight spot.

Next, find five 14 1/2-inchmobile-home tires and wheels (one for a spare). The tires are made ofbias-ply nylon for trailers. Their load capacity is greater than 15-inchsteel-belted radials, and they tow better, according to those who know.If your budget allows and you feel you must have 15-inch wheels, tandemaxle assemblies with springs and brakes are available from severalsources. There should be at least one trailer-axle dealer in your area.Be prepared to spend $350-plus for a pair of 2,500-pound axles (more forheavier ones), and then put on some good used tires.

In many cases, themobile-home trailer tongues are also underneath. If you don't mind usinga 2 5/16-inch ball, one of these can be made to work. That will save afew more bucks. I like high, forward-mounted brake lights andtaillights. The lights on this trailer are up high on the tire rack.They are visible from any angle and don't get knocked off, a constantproblem when mounted low and at the rear. It's a good idea to usereflective tape on the rear of the trailer. In Texas, where this buildupwas done, there has never been a problem with this arrangement. If thegendarmes in your area are more critical, add some lights at the rear,protecting them as best you can.

Some tools and equipment will be neededfor construction. A cutting torch, a 14-inch cutoff saw, and a welderare the basic items. A hand-held angle grinder will let you clean up alot of rough edges, too. You will need excellent welding skills. If youdoubt yours, hire the welding out.

A list of materials needed toconstruct the trailer appears with this article. There may also be a fewpieces of scrap in your shop you can use. Now let's build it.

THE AXLES

For our purposes, the outside width of the trailer is 98inches. This allows a bed width of 78 inches with a tire clearance of atleast 1 inch. Mobile-home axles are too long in the beginning, andnotice the crown in the center of the axle. This flattens out with theweight of the mobile home. Cut out this section to achieve the properoverall width. With this accomplished and the ends rewelded, the axleshould be straight. Weld it back together after grinding a bevel on bothends. This will aid in weld penetration. Before you weld the axle backtogether, don't forget to align the spring pads with each other. I used0.030 wire in the Millermatic (see sidebar) for this entire project. Imade two weld passes around the axle to fill the bevel and leaving abuilt-up bead.

Using the piece removed from the center of an axle, maketwo 8-inch, half-round pieces. One of these was welded to the bottom ofeach axle joint for additional strength.

Remove the springs and turnthem over so the spring will be below the axle. This will lower thetrailer about 31/2 inches. Hopefully you found axles with the shacklesand pivots to make it easier. The axles are finished for now.