[mitchntx]

IN an effort to lose weight off the race car, I want to cut the SFCs off. However, I use them to jack up the car.

After seeing several "pro" teams use a receiver/stab setup off the roll cage, I began fabricating this kind of rig.

I used 1" square tubing as the receiver and gusseted the hell out of it to keep deflection to a minimum. I have some 3/4" solid bar stock I was using as the stab.

After welding the receiver portion to the cage and mocking up the stab with plenty of gussets, I tested the rig and ... it bent. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/mad.gif) 3/4" solid bar stock bent like a pretzel.

And it yielded right at the end of the gusseting. Think of it as a pry bar.

I opened the door and placed the jack on the end of the receiver and lifted the car without an issue ...

So help me out here ... what can I do to the bar stock I have to increase it's strength or what kind of 3/4" bar stock can I source that will lift 1500lbs?

[mitchntx]

The stab ...

(IMG:http://www.lawmotorsports.net/Pics/Mitch/stab.jpg)



The stab fully inserted.

(IMG:http://www.lawmotorsports.net/Pics/Mitch/stab_receiver1.jpg)

After closer inspection, it appears the end of the receiver is deformed as well, just beyond the gusset on top.

Again, the stab was a mock up in order to find the weakness. I didn't spend a lot of time on it.

I added in about 10* off vertical because I realized that as the car goes up, the angle change would add leverage.

Maybe I didn't add enough angle?

Maybe I under built the whole rig?

[RichardP]

(IMG:http://www.lawmotorsports.net/Pics/Mitch/stab_receiver1.jpg)

Good stuff Mitch. I've been wanting to add a jacking point to my car but haven't gotten around to it.

Reducing the moment arm is the best way to strengthen your setup.

I'm a little confused, though. By adding the diagonal back down to the rocker sill, you have effectively added an additional attachment point to the cage. That would make this not CMC legal. Is that what you were going for???


Richard P.

[StanIROCZ]

Good stuff Mitch. I've been wanting to add a jacking point to my car but haven't gotten around to it.

Reducing the moment arm is the best way to strengthen your setup.

I'm a little confused, though. By adding the diagonal back down to the rocker sill, you have effectively added an additional attachment point to the cage. That would make this not CMC legal. Is that what you were going for???


Richard P.

Aww Crap, there are mustang guys hanging out on this forum (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif)

Here's roughly how I was planning to do it when it comes time to do my cage. I think this would add the smallest amount of mass to the chassis by putting most of the mass in the receiver.

(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/stab_receiver1.jpg)

The verticle part could be made from a 2 pieces of flat stock and then weld in the square "hole" to receive the receiver. You might want to box in the back side of the verticle with another piece of flat stock, or just start out with a square tube and cut the square hole in it. There's more than one way to do it.

I wouldn't think that you would need anything more that 3/16" steel on the chassis side. Might be able to go thinner but I'd have to throw some math at it first.

Center the verticle at the CG or maybe slightly rearward since that will allow more height which will reduce the stress on you cage tube.

This post has been edited by StanIROCZ: Nov 26 2008, 02:16 AM

[mitchntx]

Aww Crap, there are mustang guys hanging out on this forum (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif)

Not so fast ... he's bi!

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/nutkick.gif)