Show Me Your Race Car Trailers

[BezerkR32]

main concern with s-hook style fasteners is in the case of an accident, which we hope never happens, the s-hook open up and you loose the load, sometimes off the trailer and onto the tow-car. i have personally seen this happen. I have been useing 2500kg ratchet straps with the ends that clip over themselves for years and havent had any issues. Usually use a safety strap also incase the car tries to come off the back.

Hook and keeper or s-hook ratchets and why?

My tie down points (eye bolts) are suited nicely for s-hook but not at all for hook and keeper style ratchets. I could use a d-shackle to make it ideal but I see plenty of s-hook style ratchets that are easily rated above what I need.

[mitch_SR32]

If you tie the car down correctly using the S hook style ratchet straps then in case of accident you shouldn't have a real problem, since the car should be tied down front and back there should never be enough slack for the hooks to open up.

Of course if the accident is serious enough to move the car that violently then I would guess no matter what is holding your car down it will bend/break or whatever you attached it to on the car will bend/break.

As a rule for safely tying things down we (Army) use a % of the cars weight to determine what is needed to tie it down, and that is:

80% front movement

50% rear movement

20% side movement

Now front movement means the straps holding it from going forward (for those not to sure) and rear and sides are self explaining. Side movement can be alleviated by tying the car down at angles, ie: going through the standard tow hooks and out at 45 deg to the front/rear of the trailer BUT! if you tie it down this way you have to add the percentages together since you are putting more stress on the straps this way

Most importantly don't forget to check over your straps often, its a very quick check to see that the sides aren't fraying, if they are and you keep using them to tie things down then you run the risk of having them tear right through and you lose your load

Happy towing!

Edited January 3, 2009 by mitch_SR32

[benm]

So if the vehicle is 1000kg you would use 2x 800kg straps (or 2x 400kg = 800kg straps?) tieing down the back to stop forward movement?

I'm not really worried about the capacity of the straps as for anything with a decent quality ratchet they are all 2500kg.

[mitch_SR32]

If you use 2x 400kg straps to tie down the rear it won't be enough according to another rule which I forgot to mention:

When tying something down you have to assume that at any given time only 1 out of 2 or 2 out of 4 straps can end up taking all the load. Of course if you use the same strap to go through 2 points this is ok too, so long as both sides are made tight when you ratchet it down Here I am talking about hooking the strap at one corner of the trailer, running it through the 2 tow hooks (or whatever you use) and out to the other corner of the trailer.

Using the % method above with a vehicle weighing 1000kg, you would use as a BARE MINIMUM:

800kg straps to tie down from the rear

500kg from the front

200kg from the side

But as you said, if you use a 2500kg strap then that is overkill for any track car, so I always tell people to go for something like this if they are in doubt. There is no point running on the edge of your strap capacity.

Just personally, I am really not a fan of wheel straps since they do nothing to keep the body from moving on the suspension while the rims are held firm to the deck, which can get very annoying to drive with sometimes.

Edited January 4, 2009 by mitch_SR32

[Noddy]

I bougt this little Atlas 200 about a year ago and it's not bad, just slow on the hiway. I might put a VH45 auto in it. If I do that i will rebuild most of the enclosed part of the tray into a motorhome and build an enclosed 5th wheel style trailer. These are the only pics which are from the day it came home. I am remaking the tray at the moment so the top can be a track side Grandstand (esp good for events like Gatton) and the sides are the same as a toughtliner that can be tented out to make a pitbay with shade. Funny thou, Im not sure I realy want to keep it. will have to take some new pics some time.

[Beer Baron]

sweet rig. now I want someone to buy my atlas and do similar with it. it's a bit newer than yours, but probably pretty similar. (well except for the alloy pantec vs ramps etc).

I've been trying to flog it for months now. at this rate I'll be lucky to get $18K for it. and it's like brand new... so if anyone needs a truck, give me a hoy.

[benm]

Will you lease it out?

[Neil]

That's some pretty damn smart stuff you posted Mitch. After watching some guy's tie their race cars down maybe I should print it out and hand it out.

I use 2000kg straps to all 4 wheels but I have no choice,,,got nowhere else to tie down. Besides my car weighs 500 kilo's wringing wet.

On long hauls I also chain the car front and rear on it's tow hooks,,,not tight but with very little movement.

Neil.

[mitch_SR32]

Thanks, (although honestly it's the tip of the iceberg, I kept it as simple as I could since we are talking small loads) going through the wheels doesn't hurt it, it just means you have some body roll on the trailer. Since race cars are usually stiff this isn't a real problem.

I should hope I know what I am on about after 5 years in the Army recovering any number of broken things onto trailers and tying them down for some very long rides And yeah, some of things I see tied down around town and at race meets just makes me cringe!

Edited January 5, 2009 by mitch_SR32

[Neil]

Thanks, (although honestly it's the tip of the iceberg, I kept it as simple as I could since we are talking small loads) going through the wheels doesn't hurt it, it just means you have some body roll on the trailer. Since race cars are usually stiff this isn't a real problem.

I should hope I know what I am on about after 5 years in the Army recovering any number of broken things onto trailers and tying them down for some very long rides And yeah, some of things I see tied down around town and at race meets just makes me cringe!

This is one reason I started this thread in the 1st place. I wanted to see what other guys do and get great tech posts like you have. Nothing like talking to an expert.

I remember a story about Victor Brays door-slammer not tied down properly coming back from WA one year and it copped a real beating bouncing around in their trailer across the nullabor.

I'm not real happy with the way my car ties down as I have to use the centre of my wheels and that can't be good for my wheel alignment.

Duncan pretty pic on page 4 is what i think is right but I don't have the room.

Neil.

[mitch_SR32]

Expert...

Well I wouldn't quite say that but I do get paid a fair bit to know these things, its a definite advantage considering I had to move my own car by trailer twice in the last week.

If anyone has any other questions past what I have already posted fire away, either by PM or in here which is probably best so hopefully I can give an answer everyone can use

Edited January 5, 2009 by mitch_SR32

[STATUS]

yeah correct hook up is paramount we have done over 150,000kms towing in the past 19 months, and in 3 and a half years the race trailer and poor old GU patrol (second engine ) have done 210,000kms going to and from DA, G1, initial drift and general sprint days at wakefield, winton etc.

i prefer to hook the rear via the K FRAME (just behind lower arms see pics) in a"X" pattern and the same on the front tow hooks, i personally NEVER hook throught the wheels on anything that is worth a damn as it stresses suspension mounting points and effects wheel alignment especially after long trips.

We had the trailer made to make it easy to load, one of the highest priorities was no removal of bumpers to load, low tyre racks, lowered hieght to keep it under the GU's roofline (fuel efficiency), lightweight as possible, dual spares and longest ramps possible.

Edited January 5, 2009 by URAS

[hrd-hr30]

K frame is not an ideal tie down point. You really want to use unsprung components. The movement of fully sprung components will be continually slackening and then shock loading the straps as they tighten... worst case scenario for snapping a tie down, and at very least can loosen them. The only way your wheel alignment can change by tieing down to suspension members or wheels is by bending something - and that's only likely to happen in an accident.

also take issue with the 80% of body weight for front movement idea. That will be fine if an accident would only pull 0.8G in a front on accident, but that's not realistic. You want gear with SWL at least 2 times the weight (200%) of the vehicle.

I use a big f**koff chain on the rear with rated shackles to an unsprung component, or at least the outer end on a semi-sprung component like a suspension arm. Handily my race cars are typically Datsuns with live axle rear ends so I just loop around the diff housing. Then tension that forward with ratchet straps around the front wheels (never had any wheel alignment problems towing up to 1200km at a time interstate) and add an untensioned safety chain around the front x-member too.

Edited January 6, 2009 by hrd-hr30

[STATUS]

K frame is not an ideal tie down point. You really want to use unsprung components. The movement of fully sprung components will be continually slackening and then shock loading the straps as they tighten...

hence the fact you tie it in an x pattern to the rear and front of the trailer... not directley down. On a std car it may be an issue but we are talking race cars and in 10 odd years have never had a tie down break even in the unfortunate event of the car collecting a roo and leaving the road, trailer (previous setup, and years ago) bounced a mutitude of trees....

At the end of the day it is really personal prefference.

we tend to tow looong distances and find the trailer is heaps more stable at high speed (crossing the nullarbor and centre) if the cars is unable to bounce around on its suspension.... same principle as transporting trail and dirt bikes.

quick note to to those who tow cars with wings MAKE SURE YOU SET IT FLAT as it makes a HUGE difference to fuel economy and speed.

Edited January 6, 2009 by URAS

[mitch_SR32]

K frame is not an ideal tie down point. You really want to use unsprung components. The movement of fully sprung components will be continually slackening and then shock loading the straps as they tighten... worst case scenario for snapping a tie down, and at very least can loosen them. The only way your wheel alignment can change by tieing down to suspension members or wheels is by bending something - and that's only likely to happen in an accident.

also take issue with the 80% of body weight for front movement idea. That will be fine if an accident would only pull 0.8G in a front on accident, but that's not realistic. You want gear with SWL at least 2 times the weight (200%) of the vehicle.

I use a big f**koff chain on the rear with rated shackles to an unsprung component, or at least the outer end on a semi-sprung component like a suspension arm. Handily my race cars are typically Datsuns with live axle rear ends so I just loop around the diff housing. Then tension that forward with ratchet straps around the front wheels (never had any wheel alignment problems towing up to 1200km at a time interstate) and add an untensioned safety chain around the front x-member too.

1: Going from the K-frame is not a problem because it is an unsprung part of the car, the only place you should never ever tie down from is axles. No violent movement is going to occur if you have tightened it properly.

2: Where are you getting this 200% figure from? because if its simply based on an accident then I can tell you what will happen right now:

- The chain you are using will be fine since you factored it in for this big accident but its not immune to stretching either

- It will bend/break whatever you tied it to on the trailer AND the car since these aren't rated for this accident

- There is really no way to work out how to tie something down to save it from damage in an accident, hence why I doubt you will find anyone that can tell you how to tie something down with enough force (while not bending anything) to keep it stable in an accident

[mitch_SR32]

we tend to tow looong distances and find the trailer is heaps more stable at high speed if the cars is unable to bounce around on its suspension.... same principle as transporting trail and dirt bikes.

^^^^^^^^^^^^^

This

What is happening there is you don't have a constant shift in the CG (center of gravity) which can feel like the trailer is putting the brakes on as you drive.

Edited January 6, 2009 by mitch_SR32

[mitch_SR32]

One more thing, because I know a LOT of people don't do this and it can save you from losing your car clean off your trailer even while just cruising on the highways.

CHECK YOUR TIE DOWNS!

You should after tying it down check them at 3 key intervals:

200m after moving off (if the straps aren't on properly most of the movement is likely to happen in this short space, I personally have had to rip everything off and start again due to movement in this short distance)

3-5km after moving off (if you did it right on the first check then this should be a quick tighten or nothing at all)

Every time you stop after that (you are already stopped so what is hard about checking your car again)

The last step is something I see a lot of, people walk around to find straps loose or about to come off and say "jeez lucky I pulled over when I did". Don't be that person

[tacker]

trailer crash is my worse nightmare

[hrd-hr30]

1: Going from the K-frame is not a problem because it is an unsprung part of the car, the only place you should never ever tie down from is axles. No violent movement is going to occur if you have tightened it properly.

K frame is mounted to the body - its a fully sprung component.

tieing down from fully sprung components means if the car's suspension compresses slightly when you hit a bump, the tie down goes slack and then the car's suspension rebounds and shock loads the restraint. A loosening restraint also allows the load to move. Tieing down from unsprung components which stay perfectly still in relation to the trailer keeps constant tension on the load you are trying to restrain. That has to be the best way to go.

2: Where are you getting this 200% figure from? because if its simply based on an accident then I can tell you what will happen right now:

- The chain you are using will be fine since you factored it in for this big accident but its not immune to stretching either

- It will bend/break whatever you tied it to on the trailer AND the car since these aren't rated for this accident

- There is really no way to work out how to tie something down to save it from damage in an accident, hence why I doubt you will find anyone that can tell you how to tie something down with enough force (while not bending anything) to keep it stable in an accident

the 200% figure was just plucked out of the air. But the idea is to allow a safety margin rather than just speccing them to 8 tenths of the weight they're trying to secure. for example, my old U2L IPRA race car weighed 851kg - your 8/10s rule of thumb whould mean all I need is a single strap rated to 680kg! I use two 800kg straps to tension the front and prevent the load moving rearwards, wheras with your system all i need is two 200kg straps. may as well use Telstra rope!

I don't know what kind of G force a loaded trailer/4WD combo can pull under an emergency braking situation - maybe .5 to .6G?? Passenger vehicles can do .8 to .9G if I recall the wheels/motor tests correctly, so .6G is 50% less braking force than that which is probably realistic enough. There goes 3/4 of your SWL (safe working load) just in braking alone - not much margin for safety left, is there? I'll continue to err on the side of caution. It may be uneccesary/overkill, but it just has to be safer than strap only rated to 8 tenths of the load its trying to hold.

And yes, if there is a crash and parts of the trailer or car that the restraints are connected to bend, I'm fine with that - its much better than the alternative of the restraint breaking and the load flying off to cause more damage. Even if it still didn't hold, it has to absorb more energy before something breaks.

Edited January 6, 2009 by hrd-hr30

[fatz]

neil still happy with it

her first real trip

even more in love with the gu

5 tones all up newcastle to sydney with a sr20 in the boot as well

awsome!

fuel economy shithous!