Coochas

My 986 sits so low that even with the fenders off of my Featherlite, I can't open the door without hitting the trailer tires. If I pulled within an inch or so of the stone guard on the trailer, I could get out of the car but the car would be too far forward for optimal tongue weight. I realize I could then roll the car back a bit by hand but I am fat and lazy.

So, I bought a set of Race Ramps that are specifically made for this situation. I believe they raise the front wheels about 3 inches and I can now open the door. The nice thing about these ramps is that they are concave so that when you pull onto them you know it without needing someone to spot you. I drove back and forth from Boston to Limerock and the ramps did not move at all. The weight of the car plus the tie downs on the car seem to keep the things in place.

I also had purchased a 2-jug diamond plate fuel jug holder. Unfortunately, my 5-gallon Hunsaker jugs were too big for the rack. So,....I cut the rack in half and then mounted each half on either side of my trailer by bolting it to the floor. For security, I run a thick cable lock through the D-rings and through the handles of the jugs. Works like a charm and I think it actually looks decent despite my metal work.

Next stop,.....enclosed trailer. LOL.

RickBetterley

Nicely done, Dave - how much vertical clearance do I need to clear the ramps? I've thought about them as a way to set the car in position and to raise the front end for when I need to reach under and attach the straps.

Coochas

The ramps are pretty gradual. Here's a link: http://www.raceramps.com/trailer-mates.html
You're very welcome to come to Cambridge and try them to see if they clear. I'll also have them at the Calabogie and LCMT events in July. I tie my front straps to the front jacking points on the car (by a Rennline plate). The extra lift with these ramps makes it much easier for me to get my hands under there.

VERBOTN

......stop laughing you are closer than you think. looks great.

RickBetterley

Hi Dave
I'll be at Tremblant with you in July and maybe I can take you up on the offer. Thanks

BostonDMD

Hey Dave, when are you going to move to real tires like Hoosier?

Just wondering......

mglobe

That first step on the slippery slope was doozie, wasn't it?

ltc

Nicely done Dave. It's too bad Hunsaker apparently went out of business, I always liked their fuel jugs.

Make sure there are no rivets, bolts or anything else that can possibly rub up against the jugs (sides or bottom). Be careful of the plastic wearing thin due to vibration.

Please allow me to offer this suggestion from my karting days:

Get some thin rubber/vinyl mat (I got mine from someone who did printing press work...pretty much impervious to chemicals) and place it on the inside of the jug holders (you can use spray on contact adhesive or 3M VHB tape). This will protect against wear due to vibration.
I used to place this on the floor pan of my son's karts, as over time, they would sometimes wear against the tank bottom (lots of vibration) and become "thin"...usually resulting in a leak, followed by the driver complaining he couldn't see due to fuel/oil spray, followed by his mother (team President) yelling at me (hired help).

mglobe

Not legal in SpecBox

Coochas

See you then.
Brutal,....just brutal. But my marriage is still lintact. Phew.
That sounds like a smart prophylaxis Lewis. I did put some tygon tubing along the sharper outer edges of the diamond plate where I cut it, but I think I should do a little more 'softening' of the area.
Thanks!

ervtx

Looks like you have the front tie downs attached in cross over style (same as in the rear). You're familiar with all of the previous threads on this, but it's worth noting that just as you introduce greater force on the straps when longitudinal forces tug on horizontally angled straps, the same is true on vertically angled straps (caused by the increased height of wheels relative to the D rings). Computing the effect of both vertical and horizontal angles to the direction of braking and acceleration forces requires higher order math, but I'm pretty sure that you want to make sure that your straps have a plenty margin in terms of rated load capacity.

I once broke a Rennline tow hook (bent the metal loop) by trying to winch my car up on just such a set up. The winch was mounted on the surface of the trailer. As the car rolled up the ramps and vertically higher off of the surface of the trailer, the forces on the tow hook increased dramatically.

kristap

woa - dont want to threadjack but when did hunsaker go out of business?

Coochas

OMG, my head is spinning!
Thanks for the heads up.

Coochas

No worries. They recently disappeared. I'm glad I got these jugs though as they really are quite ergonomic during filling. And they hold 6 gallons in the 5 gallon container....like amplifiers that go to 11 instead of 10.

ausgeflippt951

While you're correct in that the mounting points experience forces in the x- and y- and z- directions when the car is loaded to the trailer in such a manner, you are incorrect in assuming the straps will fail.

As far as the ratchet strap is concerned, no matter which direction the load is coming from, the strap itself is always loaded in tension. Meaning, the strap only experiences forces in one direction -- and that is the direction it is designed for.

I just did a few back-of-the-envelope calculations and sure enough, the forces 3" or 4" ratchet strap experiences are well below the tensile strength of the polyester webbing. Even a 2" strap is stronger than needed for most light braking applications. (That said, I'd still go with a 3" or 4" in case something more dramatic happens)


As you alluded to, it's the mount that will be experiencing the load in the x-, y-, and z- directions. Assuming the trailer is in good condition (which it seems like it is), the mount on the trailer will be fine.

Additionally, the mounts (i.e., toe hooks) on the Boxster are perfectly strong enough to handle the forces from the ratchet straps. This comes with a caveat, however: the mounts must be loaded in tension themselves. Meaning, if the "direction" the mount is oriented is off-axis from the load, under sufficient load the mount will bend until it faces a direction in which it is loaded in tension.

However, it's doubtful that the metal will bend as much as is needed, meaning it will most likely fracture prior to bending all the way. Or, if it does bend, it will bend at its own mounting point: the bolt holding it in. This can be detrimental because at this point the bolt becomes loaded in both tension AND shear (however, the force in single-shear will be decreased). Even still, assuming the bolt is properly sized and is in good condition, the mount itself will most likely fail first.



Sorry for the hijack and for the lengthy post...

In sum, the straps (using 3" or 4") and mounts on the trailer will be fine. How is the mount on the boxster oriented? if it's vertical and facing the rear of the car (i.e., not at an angle), the mount is in danger of failing using the cross-strap method. However, this can be alleviated by simply adding another ratchet strap running straight from the mount on the trailer to the same side mount on the car (i.e., don't cross to the other side). Yes, this would mean you'd have four straps per end of the car, which is undoubtedly overkill. But, I guarantee the mount won't fail at this point.

If you can reposition the mount somehow (I can't on my 951, given that they're attached to the shocks), making the mount horizontal (rather than vertical) will increase the mount's strength when experiencing a force coming from an angle. Or, you could completely redesign the mount so that it's oriented to be loaded in tension.



I don't know what the mounts looks like on your car. But if I did, there are a couple basic calculations that would tell you if your mount is sufficiently strong to hold the load in question. I.e., if it is, then this whole discussion just became moot. I should've put this at the beginning so that you wouldn't have had to read everything above...