Salanis
SuperDork
1/29/10 8:02 p.m.
So, I've gotten a trailer for the 924 race car. I want to be sure I know how to properly secure the thing before I use it.
The trailer is an open trailer with a metal deck and an open center. I'm taking it to a shop tomorrow to get some extra D-rings welded to the frame to cinch it down (previous owners secured their car by cinching down the front left and back right wheels with wheel-net straps, but their car was longer wheelbase, and that seems like a poor way of attaching the car).
Seems like ratcheting straps attached cross-ways to tow loops on the chassis and tightened down enough to compress the suspension some is the general way. Correct? For the front, it looks like it might be tough to cross the straps, but I gather that having at least one pair crossed is generally good.
mw
Reader
1/29/10 8:09 p.m.
I do wheel straps over the rear wheels and a tie down to the tow hooks on the front (not crossed). I once had the trailer sway so much I thought I was going to die and the flexing of the trailer caused many of the welds to break. The car stayed put on the trailer. I am confident it's well secured.
SVreX
SuperDork
1/29/10 8:22 p.m.
You've got to have straps that go both to the front, and to the rear. On a very short trailer, sometimes I attach the front of the car to the rear of the trailer, and vice versa (under the car).
If you only pull to the rear with no straps forward, there is nothing to pull against, and the straps will loosen as the car shifts.
Crossing is good (though not necessary).
Yes, you want to compress the suspension a bit.
I usually use my strongest straps in the rear, and a minimum of 2. If I have to emergency brake, I don't want the car moving forward and running into my truck.
Redundancy is also good. I generally try to use 4 straps total- 2 forward, 2 rearward. That way, if any one of them breaks, there is always another one to do the job.
We generally use two chains to tie down points in the back, and two ratchet straps up front. Secure the chains first, then pull the car tight with the straps.
Salanis
SuperDork
1/29/10 8:38 p.m.
Tommy Suddard wrote:
We generally use two chains to tie down points in the back, and two ratchet straps up front. Secure the chains first, then pull the car tight with the straps.
Do you cross either the chains or the straps? Or just attach them strait on.
I tend to pull the wheels down either with straps that fit over the wheels, or straps/chains over the axles. Pull that down as close to vertically as I can. This ties the wheels very tightly to the trailer.
Then I strap/chain the car down with them going as horizontally as I can. These tend to be long. The car is able to bounce up and down a bit, but is very restrained from moving forward or backwards.
My metal trailer has two small stacks of square tubing welded near the front. These serve as tire stops and I place rubber padding between the metal stops and the slicks. Ratcheting straps are used at the car's front to secure it against the tire stops and I strap the back end down to prevent the car from bouncing. My D-Rings are bolted to the trailer w/ thick metal plates welded below the bed for reinforcement. Although I'm only towing a 600 pound car, the concept should work on a larger car.
A recent mod to my trailer was the addition of a vertically mounted trailer hitch receiver that I use for a removable electric winch. The winch has a 2000 lbf capacity and only cost around $100 at Northern Tool. Since you're not lifting the car's entire weight when pulling it onto a trailer, this should be a strong enough winch for most street cars.
If this is your first time towing a strapped on car, be sure to stop after 15-30 minutes to make sure none of your straps are loosening. Sometimes changing where you place the straps has an effect on how much they loosen during a trip. Learn by trial-and-error, so long as the error isn't dropping your car from the trailer.
Steven Cagle
Salanis
SuperDork
1/29/10 9:20 p.m.
Also, what weight rating should I get for straps? I figure it's about a 2500# car.
my trailer has a superwinch S5000 on the front. i hook the cable up to frame or axle, depending on if i am backing on or pulling on. then i run 2 straps to the back of the trailer and put a little tension on the winch. then i run 2 more straps forward and ratchet them down. i love redundancy when it comes to tying stuff down. i figure with 4 straps and the winch cable i have to screw up really bad to have a car shift on the trailer.
Tie down the suspension and let the body move. I once saw a 240 Volvo rally car come back from a cross country trip with the rear frame rails sagged and the quarter panels buckled. I think it was held down by the bumper shocks.
I got 4 of the Macs tie downs that actually encase the tire, all four corners are held by 5000lb straps, each of which are held by a D ring front and rear of the tire, then I keep the winch attached, put it in gear and if there is a handbrake I engage it.
The best thing about the tire straps is the suspension is completely free to move but there is no way the tires can. Just don't let the body panels rub on the straps or they will cut them.
Salanis
SuperDork
1/29/10 11:26 p.m.
I'd read that you don't actually want the suspension moving around, because then you have the added momentum of the car's body swaying around when you tow the car.
I have never heard of a car coming off its suspension in any incident. Momentum comes from movement, the amount of movement in a soft car is maybe 4", not much to worry about there.
Salanis
SuperDork
1/30/10 12:18 a.m.
I think the idea is that it continues to sway past what the trailer does.
ddavidv
SuperDork
1/30/10 7:09 a.m.
Corner-Carvers tie down tech
Not sure if you mere mortals can access this thread or not, but there is much debate about crossing straps or not. I cross them out of necessity, based on where my D-rings are on the trailer vs the tie-down points on the car chassis. Sometimes the car just doesn't give you a lot of choice. I'm still trying to figure out a good way of strapping down my old Mini without bending the crap out of something (notoriously weak subframes and no good place to hook onto the body). Wheel straps are probably best, but unless you have E-track they may be difficult to use.
Check out what car hauling companies use, that's what I did. I did 20,000 miles last year towing without a single incident.
Just saying it works for me. I find binding the suspension to be hard on the chassis and shocks, not to mention if you hold the car down, when the suspension does move, it is constantly jerking against wherever the tie downs are touching or attached to, see the post about the Volvo rally car.
http://www.macscustomtiedowns.com/product/215/All
By the way they are an advertiser on GRM
If you look at the way the commercial car carriers tie cars down, they tie the frame and let the car move on the suspension. VW's used to come with plastic spacers on the shocks so that when the car was tied down it couldn't fully compress the suspension. A lazy PDI tech who forgot to remove those was generally rewarded with a cracked tooth on the test drive. I did see one Beetle which was tied down way too tight, it tweaked the nose of the car down to the point that the hood could not be opened or closed properly. I dunno if that's a condemnation of VW's lack of engineering or a salute to the truck driver's arm strength.
I don't like 'tire bonnets', it's tough to get the car to not move unless you use wheel chocks and if the tire loses air you are screwed. I tie down triangulated whenever possible, and don't worry about crossing the straps. The Jensenator has a single big loop welded to the front crossmember, I go out from that point to the trailer's front D rings. Then at the rear I currently use axle straps with the big wear sleeves over the axle and from there ratchet straps out to the flip up D rings I welded to the trailer deck. Position the car with the front straps and tie it down with the rear. Since this method ties the body down at the front and the suspension at the rear, I will eventually add a couple of tiedown hooks to the body at the rear.
About tie downs: the safety type which have a spring loaded closure for the hook opening add a bit of safety, since they can't just fall off if they get loose. I have a set of the big ol' tie downs available at Lowe's etc, while they are very strong the hooks are open. If the load shifts and the strap gets loose, .
car39
Reader
1/30/10 8:19 a.m.
I tie my Miata down with cross straps to the "baby teeth" in the front and straight straps to the factory tie downs in the rear. Since it already had a trailer hitch, I made up a hitch assy with two chains that attach to the d-rings in the rear of the trailer. Overkiill? Maybe, but a friend of mine was distracted putting his car away in an enclosed trailer, and only hooked the safety chains, forgot the tie downs. The rig was nearly undrivable from the car moving around, but the chains kept it from beating the nose of the car, and the inside of the trailer to death.
Crossing straps is not needed from a safety standpoint, but may be needed depending on where the tie downs are on your trailer. The DOT requires cars be tied down at four points, and a winch can't be used to secure a car. I don't know if they would bother a race car on a private trailer but given the need to generate revenue lately I don't know if I would risk it.
Confirm this on your own, but I believe you are also required to use 3" wide straps.
I also have had a swaying accident, so I take the overkill route. I do four 3" straps to tow points on the 4 corners of the car. I then take two 2" straps and put them through the wheels(front right, and back left) and secure them.
Make sure the straps don't rub on anything, as they can be cut through in pretty short order.
if you don't cross the straps you risk the chance that the car will move sideways.
I use chains to the tie-down holes in the frame and loadbinders.
It works for towing companies, it holds excavators to equipment trailers, it should hold my car down just fine.
If you use loadbinders, make sure you carry some mechanics wire with you to wire the handle shut.
Shawn
I use short chains on the front for the MG Midget racer, then cross ratchet straps on the back. By using chains I can clip them on the front tow hooks and don't have to adjust the front. I keep them short to prevent the car moving much. I put two tow hooks in the back that bolt through the trunk and the fuel cell cage (which is also welded to the roll cage). I can hook up the car very quickly this way and without a lot of crawling underneath trying to wrap the axles with axle straps like I used to do.
Sometimes I put blocks under the front and back wheels when towing long distances just to be sure. I've had friends have cars roll around in their trailers and hit something and there is nothing more frustrating. I've got a wooden floor in the trailer (enclosed) so drywall screws and 2x4 blocks make this very easy with a cordless drill.
BTW, don't be tempted to leave the car in gear when you are towing it, else the drivetrain will be taking all the bangs and vibrations.
Salanis
SuperDork
1/30/10 1:14 p.m.
Anyone have experience with or thoughts on E Tracks? One of the local 944 racers says he uses that with wheel straps and has had good luck. Seems like a good way to be able to have just the right attachment point for a variety of different cars. It would also be something I could install easily myself.
In reply to Salanis:
I have a friend that tried it and didn't like it. The e-track tends to collect dirt and crap if it is used on a floor. He also kept stubbing his toes on it. Other than that I think it was OK for holding down the car. YMMV.