How important is this piece?
I'm talking about the bar that bolts to the drivers side body (3 bolts) and goes to the mounting braket that the panhard bar is mounted to on the body.

It seems to be additional support. I've heard of people taking this off for exhaust clearance.. I really want to take it off but I just don't think GM would put it there for no reason..

 

It's been called the upper panhard bar. I know there have been some who have removed it but I wouldn't. I may sound like a broken record to some but here's my take on the situation, if G.M. could eliminate just one small washer on a car they would, that brace adds up to a lot of washers. JMO

Al

 

I agree.. But damn does that bar make 2 2.5" pipes going over the axle difficult as hell to do!! I was hoping for the easy way out.

 

I agree. I actually bent one of those on my 3rd gen Formula Firebird. I never did figure out how. At thie time I bent it it was a street car that handled well (springs, shocks, bushings, heim/heim phb and lca's, and alignment....nothing crazy). I began to hear "banging" over bumps, I found that the upper panhard bar had kinked at the bend (the bend to clear the exhaust pipe) and was hitting the lower PHB. If it bent, it must see some level of stress (though it is mounted between two solid points on the chassis, which did not seem bent). At the time this car was not raced, just driven (aggressively) to work and on backroads. Just my thoughts FWIW.

Kevin

 

2002WS6, here's my theory and I've mentioned it before. Just by inspection one can see that the PHR attachment fitting (basically a clevis) on the passenger side combined with the support brace approximate a triangulated support for the PHR itself. Without the support brace the only thing to resist the side loads from the axle/PHR will be the clevis fitting on the passenger side. While I don't know the magnitude of the loading that this attachment would see or can handle, its obvious that it would find itself in a much different loading condition than the one for which it was designed. Namely it would see a much higher moment (torsional load) at its attachment to the body than before.
Imagine it this way - you have two fence posts that are both driven a short distance into the ground (just enough to allow them to stand upright). The first post stays as is, but the second post you brace with a 2x4 at an angle. Then you apply a load at the top of each post. Intuitively the first post is much weaker. See my crude example below now turn it upside down and you have your PHR attach system.

First post Second post

-->XX...............-->XX
.....XX....................XX
.....XX....................XXX
.....XX....................XX...X
.....XX....................XX.....X
.....XX....................XX.......X
.....XX....................XX.........X
.....XX....................XX...........X
.....XX....................XX.............X


So, my advice (FWIW) would be to leave the brace installed.

I know its a pain since its in the way, but I've actually spent some time recently looking at the brace in hopes of coming up with something that would provide more clearance for dual exhausts, provide clearance for your average 12-bolt stud girdle, yet still allow full travel of the PHR in its arc. I think the only way to do it is to relocate the attach point of the PHR on the passenger side. Of course by design the PHR should be horizontal with the car at ride height (which it is at stock height), so its all a compromise. FWIW, BMR is in process of producing an aftermarket support brace that does just that. Should be interesting.

EDIT: Damn that diagram looks like **** with all those placeholders hopefully it makes some sense

 

Thank you fulton for the great diagram
That's wat I figured.. I can't wait to see BMR's new brace. I was thinking the same think, fabricate a new brace with more clearance..

Thanks!

 

I just called BMR. Their new panhard brace will relocate the brace to the panhard bar mounting position and move the panhard bar lower to a new position on the bracket.

Before:
|-|
|1| Brace here
|2| Panhard here
|-|

After:
|-|
|-|
|1| Brace Here
|2| Panhard here

The kit will give you a new brace and the necessary adapter hardware to move the panhard down. Should be avail in 2-3months. ~$129
It will give about 11/16 of an inch additional clearance.

 

My only real concern with moving the PHR attach point lower like that is that you are taking the PHR away from the preferred horizontal position. This is true when you lower the car too - mine is actually 1.5" lower on the body side vs. the axle side. So, with a lowered car you could be as much as 2.5"+ away from horizontal with the BMR brace. This will likely create some additional sideways translation of the rear axle as it moves through its travel, but since we have a pretty long PHR the change should be minimal (haven't actually measured). Either way it should provide some additional clearance for true duals, which would be nice. If the piece looks good I might also give it a try - for $129 and no permanent modification its probably worth a shot.

 

I think the guy from BMR said that it also lowers the PHR on the rear.. I think..
He definately said that they maintain the geometry of the PHR. I just can't remember how..

 

If BMR does relocate the axle-side attachment of the PHR (similar to the Ground Control PHR kit) that would be cool, but that's not the indication I got from them. I'll have to reread their email. They did emphasize that it would be a bolt-in kit and I don't see relocating the axle attachment without welding involved.

IMO a modified upper PHR like this in conjunction with a downward relocation of the PHR attachment on the axle would be a nice setup since it would lower the rear roll center as well.