[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.

[mitchntx]

(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.

You know, when I discussed this with a series director, it was concluded that it was in fact and by the strict letter, technically, an additional "mounting point" but it added no rigidity to the structure. I also noted that someone was gonna say something and he said, "nah ... no way." (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dry.gif)

I needed something to brace deflection. I only have a single bar on the passenger side (and yes, the factory crash bar is still in the passenger door).


Randy, that's a good idea. My goal was to keep everything as light as possible. Adding both those hitch receivers sorta negates the reason for cutting off the subs. I'm sure they are lighter, but not by as much as I was hoping to gain. Looks like I'm back to square one ...