Racebrick's track support trailer

This year I am driving my main track car to and from events. You can read about it Here My son and I are both competing in SCCA TT and so I had planned to put a hitch on my car and get a trailer for dragging wheels/tires/ez up, etc. I have looked everywhere for a trailer in the 4x8 range and come up with nothing. Used ones are either junk, no title, too big. New ones are all out of stock, and I mean everywhere.  So I went to my local trailer shop, to see if I could piece something together. They had a torsion beam axle laying around for a job that never happened, and even though it was narrower than ideal, at $250 out the door I was in. After getting eveything I would need to build it, I am in for about $600, which is still cheaper than it would have cost new. I looked into the existing options for a trailer like this, and was blown away at the cost. $3500, plus $1500 shipping for a tire trailer? No thanks. This was a great excuse to buy a new saw while I was at it.  I have an evolution rage 3 saw that has served me well, but has some broken parts. I bought the new version of that saw, and I am very pleased.

The diy trailer kit. I realized that I am going to go a different way with the coupler/jack assembly, and go to a 1 7/8" ball instead of the A frame, but this is where I started.

I had this square tube already, and if you look around in my shop you may notice that I really like it as a building material. I keep at least 100' around like most people. 

The basic dimensions taking shape. The trailer will end up about 5' wide, and 8' long. 

The trailer will have two integrated tire racks, so I can haul both of our sets of tires. This is the rear section and axle section.

The basic exterior shape is complete.

Sitting on the axle for a test fit. I'm happy with the basic outline.

End of day 1. After a couple hours of work, I am happy with my progress.  I am going to pivot on my coupler design, and will get some different materials today and make some more progress.

Nice design. How did you determine the location for axle centerline? 

I find it surprising you couldn't find any of the usual 4x8 Harbor Freight trailers. They make excellent bases to build into whatever you need. 

In reply to nsogiba :

60/40 length front/rear is the rule of thumb for length on either side of the axle. Proper weight balance is more important, and in my experience lighter trailers tow better with a little more tongue weight, so a little more length in front of the axle is usually good. No HF anywhere near me had a 4x8 in stock with none expected until June. I need this to tow next Friday. I had a 4x8 HF trailer, and it was very meh. Also knowing I would modify it anyway means I would have to grind a bunch of paint off, weld and repaint.

General shape of the trailer.

The tire rack is in the front of the trailer, and is lockable.

5

I am building this out of materials I had already, and some design choices reflect that. The center piece of steel is the only piece of metal I needed to buy.

At this point, I was just going to paint it, and put a sheet of plywood on top.

"Done." I had some prefab fenders I was going to put on, and a sheet of plywood.

Prefab fenders, and other trailer stuff to be installed.

I ended up building my own fenders since the prefab ones didn't fit to my liking.

Bend each side, then cut some relief tabs, and bend again.

Boxy but good.

Inner fender is just trace, cut, weld.I had to weld some smaller pieces of expanded together to create a piece big enough for the trailer.

Rear cargo area with expanded installed.

Fenders welded on.

I am also adding a lockable tongue box. so I welded in an additional bar to mount the box to.

Waiting for paint to dry, and then I will install the rest of the parts.

One question: if the tires go flat will they fall out the bottom?   Or, get stolen at the motel.   I always ran a locking pipe through the center holes.

Very nice build! I usually "repurpose" trailers, even though they have all come out better, if I started from scratch!

Yours is several magnitudes better than the HF ones!

What wall is your favorite tube? I assume 2 x 2? 

In reply to Purple Frog :

If I had a flat it's possible I would need to strap it down to the rear of the trailer. When all four tires are in the rack they are locked in place, and cannot be removed. I will take pictures of the rack when the rest is complete.

In reply to 03Panther :

I use 1.5"x1.5" typically. If you look around my shop you can see many items built from it.

In reply to Racebrick :

Thanks.  Dimensions are hard to tell in the photos. Friend of mine built some of his family room furniture same way! Cool stuff. What wall tube did you use for the trailer?

do you need to run shocks or is the torsion axle good enough ?

The center beam is 2"x2" 1/4". The other tube is 1.5"x1.5" 1/8". Total trailer size is 5'x10'. The axle is a torsion beam, so I am going to assume it won't need any other suspension. I will weight the trailer when I'm done, but I think the gross weight will not be any more than 800lbs.

Love torsion axles!

You should consider having the trailer run the same wheels as the car if possible, it could be very handy if they can share spares even as an emergency option. Torsion bars alone should be enough suspension for a trailer this size. I've also thought it would be handy to make sort of a portable mini gas station built into such a trailer, with an electric air compressor and maybe a boat gas tank with an electric transfer pump.

I did consider the wheels, but there is no point in my case. I will have an extra set of wheels and tires with me when using the trailer. I also thought about adding a bunch of neat things into the trailer. Air compressor, 12v battery, integrated storage, etc. It's easy to go overboard with making it cool, but after considering my use of it I believe this to be the best design for me. I also have an enclosed trailer that has some pimp features. I plan to tow the car to bigger events, or farther distance.

In reply to GameboyRMH :

Many years ago I built my own autocross trailer to haul behind a VW GTI. The trailer ran a K-car axle and VW GTI rims. I even had Yokohama 001R tires on it, like the car ! I could take off ramps at silly speeds and the trailer would just follow along.

I finished the trailer a while back, but never updated the thread. I mounted a tongue box, put some plywood sheet, and some etrack I had laying around. I did 800 miles round trip last weekend with great results.

Fast cars towing little trailers is the best. All you're missing is a cooler and a mini grill.

I dig the "more Etrack than my body has room for" method. I need to add Etrack into my tie-down game.