Building 2-car trailer

[irondragon]

- 025
More free advice - and possibly worth what you're paying for it.
Tires: Consider running ST rated tires (Trailer Service). They are designed to run at 50 psi and will carry about 20% more load than the same size auto tire. I don't know what the cost premium is but they save a lot of tire changing agony.
Sooner or later you'll have to stop reading all this stuff and actually cut metal.
Bill Miskoe

[irondragon]

-025
Correction on increase in stiffness by using 2x6 tubing.
I should have compared the Section Modulus numbers, not the I values.
Stiffness increase is 60%. Weight increase still is 6%.
Best Regards - Bill Miskoe

[racer-025]

Thats one VERY nice 2-car trailer! Wish I could afford that one. I'd probably go inclosed though....

When I started this tread, my trailer was already 75% finished. Good, bad or ugly - it is now finished. I did notice that it is perfectly balanced. Maybe thats not a good thing as empty vertually no weight on the hitch. I havn't had a chance to load it up and test it yet. It does have "trailer" tires, C-rated. I'm going to try to get the front car as much forward as possible to get as much weight on the hitch as possible.

Chuck, its only going to carry 4000lbs so I think it will be OK. If not, I'll take your advice and add a 3rd axle out the back and/or bridge the outside members and stiffen it up.

Bill, thanks for the engineering math. I'll load her up this week and take it for a test drive.....

[racer-025]

She's all loaded and were heading to the Targa Newfoundland Rally.

www.targanewfoundland.com

I'll let you guys know how we make out in 12 days....

BTW, I did modify the hitch on the motorhome. It had frame extensions and I beefed the hitch up by welding a 2x2 across the frame and then another 2x2 welded to the hitch and used angles to tie the frame extensions to the 2x2.

I'm glad the gas tank has no leaks....

[racer-025]

I'm back. We just did the 1600 mile trek. The trailer had no problems. It actually hauled quite well without any swaying. I didn't need the load dis hitch because the trailer was perfectly balanced - probably not a good thing. We loaded both cars facing forward and as far forward as possible, putting some weight on the hitch. It did have some flexing of the frame when going over rough roads, mainly under the rear car. The springs did absorbe most of the bouncing. The axles and tires were plently tuff enough to handle the job.

Some things I will change:

I will move the axles back probably 18-24 inches to get more load on the hitch and to help stop the flexing in the rear.

I will bridge the outer frame rails to help stop the flexing.

ps.... We did right-off one of the CRX's. End-for-end rollover down a 12' bank. No one got hurt. After the crew got out of the car, a big-dollar Mustang landed on top of the CRX. Anyone have a spare CRX tub forsale???

picture of red crx upsidedown:
http://www.geocities.com/mcnuttracing/targa.pdf

[This message has been edited by racer-025 (edited September 29, 2004).]

[chuck baader]

A couple of notes....I agree with moving the wheels back..will also make the trailer more stable. As far as adding bridge to the outer frame rails, I would not do that as long as you are getting plastic deformation in the structure. A bridge must flex or it will break. Same with your trailer..let it flex as long as there are no cracks, etc. My trailer is a "flexie-flyer" over many races the last three years with no problems. Good Luck, Chuck

[lateapex911]

So sorry about that....and they called you a "speed bump"!! You gonna take that??!




------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[racer-025]

That Pacione Mustang crew stole the "H" emblem off the hood of the Honda, glued it to the front of their car and put a slash through it. I'd have to say, our Honda saved their bacon. If it wasn't there, they would have rolled too. They worked all night on that car and it was back in the game by 8:00am the next morning.

Chuck,

There is no cracks within the frame. So you think I should not bother to bridge the outside rails and let it flex? Most of the flex would probably be gone if I move the axles back don't you think?

BTW, that '61 Vette in the picture, broke it's steering shaft and ended up in the woods at 100mph! It too, was fixed up and put back in the game.

[This message has been edited by racer-025 (edited September 30, 2004).]

[chuck baader]

When you move the wheels back you will be making a longer bridge between the car and trailer wheels. At the same time you will have less overhang behind the wheels. I would think that would lessen the movement.

The bridge between the car and wheels will need to be watched simply because it will be a longer span, flex more, and more inclined to break if over flexed.

Were it mine, I would move the wheels then load and find the roughest road around to give it a smoke test close to the welder. CB

[racer-025]

Yes, I definiately want to have it all well tested prior to getting it hot dipped.

Chuck,

After I cut off the spring hangers, what do you think of maybe welding a L angle (2"x 4") on the bottom and outside of the outer frame rails. Then weld the spring hangers back on. Wouldn't that stiffen up the fame enough to still let it flex some, but be stronger for the front car?

[chuck baader]

I assume you mean from the new spirng perch location to the tongue? I see no problem with that, but I would stitch weld it, not solid. CB