Possible to have too much tension on a rear cross bar rxb?

[az_240]

Probably a stupid question but it has been bugging me. This is for a Do-Luck rear cross bar on an s14. First off I accidently installed the stabilizers upside down like a dipshit when I first installed everything and that pulled the tranny tunnel up about an inch and it made my seats sit slightly higher and angled... so I was kind of worried I might have stretched or weakened the metal slightly.

I installed everything correctly but was not sure how much tension was needed for the bar to be most effective. I asked around and someone said to just tighten it as much as you can and leave it alone.... so I did with a large adjustable wrench.

Now im thinking it might be a little too tight and that area could become stretched over time or welds could possibly pull apart... I pulled back the carpet a little to check the frame and see if its bending from the tension and it seems it is a little but doesnt look bad.

http://i12.photobucket.com/albums/a229/livinglegendlll/ImportedPhotos00000-2.jpg
Here is a pic of how tight it is for people who own one..,

Am I just paranoid?

Do you think that if I remove the bar that area would be weaker than it originally was? Im thinking of selling it because im broke.

[projectRDM]

If it's properly installed you're going to weaken the chassis. It's pressing out on an area that is heavily reinforced, with numerous layers and welds. I wouldn't stress it. I had one over a decade ago and followed the words then, jack it up slightly to unload the chassis then tighten to it's maximum point.

[Def]

Wouldn't you want the bar in compression since the primary mode of chassis flex will be bending across the trans tunnel, thus decreasing the distance the bar is mounted to?

Or are you just misusing the term "tension" to imply stress on the bar?

[az_240]

Im confused....

the bar is supposed to press OUT against the frame right? That is what I meant by tension. You turn that buckle in the middle and it moves the bars away from each other creating tension on the frame.

What do you mean if the bar was properly installed it will weaken the chassis? You mean if I removed it?

and I thought it was best to install the bar while the car was on flat ground???

[codyace]

I installed mine a few years back, and got it snug using a big adjustable wrench, and then just tightened it. I installed mine on the ground, as it's the same thing we do with subframe supports on Fox Bodies.

In terms of pinching the trans tunnle up and stuff...that's freakin wierd!

[CinSun]

Im confused....

the bar is supposed to press OUT against the frame right? That is what I meant by tension. You turn that buckle in the middle and it moves the bars away from each other creating tension on the frame.

What do you mean if the bar was properly installed it will weaken the chassis? You mean if I removed it?

and I thought it was best to install the bar while the car was on flat ground???

if the bar is pushing out against the frame, the bar is in compression, if its pulling the frame inward then the bar is in tension. depending on how and where the cross bar is bolted up, you might be bending the frame which is actually putting it in tension AND compression at the same time. whichever way you look at it though, it doesnt make any sense to have the cross bar pushing out against the frame as its just putting unneeded stress on the sheet metal and won't be helping with structural rigidity.

I'm curious, what exactly is the marketed benefit of installing this cross-bar? From what I understand, the structural stresses in the car are concentrated more towards the front and rear, not so much towards the middle of the car. Not sure how much you payed for it, but it sorta sounds like a waste of money to me.

[Def]

It's not the most effective brace, but the trans tunnel does make the middle of the car weak in bending/compression(i.e. easy to push together and "crush").

You want the RXB in compression... pressing out against the outside of the unibody.

[CinSun]

my bad, i guess i was giving advice without fully understanding the function of the bar.

[projectRDM]

I'm curious, what exactly is the marketed benefit of installing this cross-bar? From what I understand, the structural stresses in the car are concentrated more towards the front and rear, not so much towards the middle of the car. Not sure how much you payed for it, but it sorta sounds like a waste of money to me.

It does seem frivolous, but it works. I bought one from DoLuck back in '99 when I first saw it somewhere, thought it was cool. It's a heavy duty piece, very solid, and I could feel a difference after installation during autocross and mountain driving, through switchbacks when you're swapping the load of the car from side to side. There's definitely less 'wiggle' in the chassis under those conditions. The Schassis likes to twist when thrown into a turn under acceleration, similar to older Mustangs in the rear quarter area (especially convertibles), though not as pronounced. This is a good piece to reduce some of that.

[codyace]

It does seem frivolous, but it works. I bought one from DoLuck back in '99 when I first saw it somewhere, thought it was cool. It's a heavy duty piece, very solid, and I could feel a difference after installation during autocross and mountain driving, through switchbacks when you're swapping the load of the car from side to side. There's definitely less 'wiggle' in the chassis under those conditions. The Schassis likes to twist when thrown into a turn under acceleration, similar to older Mustangs in the rear quarter area (especially convertibles), though not as pronounced. This is a good piece to reduce some of that.

Fox Body cars make S chassis cars feel like solid pieces of iron in terms of flex.


I loved my brace...certainly a great addition to a street oriented car. I've since installed a roll bar, and took it out though. I've got quite a few ideas that I'm going to implement over the winter, after I get done working on other stuff.

[az_240]

Thanks for the replies.... I guess I was just being paranoid....

As for function I did notice a difference when swapping the load of the car from side to side and even when going over bumps on the freeway. Its a very solid bar and the stabilizers seem to help.