removing panhard bar brace????

Anyone here remove the brace that runs from the panhard mount to the driverside frame? I want to get rid of this for exhaust clearance. I have an aftermarket panhard bar so it should be strong enough to handle the load. The car is not a road race car. More of a drag car. If this can be done without causing any problems, let me know. Thanks.

That upper panhard bar is there for a good reason. Removing it is a very bad idea in my opinion.

Let me explain, the entire rear axle is prevented from shooting sideways out from under the car by the panhard rod. That force is sent into the panhard bracket. The upper panhard braces the bracket and shares the load in tension and compression. Without the upper bar the force gains a lever arm of 3-4" on the panhard bracket and the load on the bracket increases by 100% + the effect of the increase of the lever arm. That could break the bracket and twist it off of the body.

The handling will not change alot until you break the bracket. At that time everything will go to hell in a hurry. It could cause a bad wreck, and it will fail in a turn.

It is your car, and I don't mean to bust your chops, but this is very bad idea. Would you drive on a bridge if they were cuting out the braces along the side? It is the same effect here.

Z28

Z28 barnett, thanks for the advice. I'm going to take it out, but I'll fab up a new one for exhaust clearance. John, you are an ass. Don't forget who's garage you expect to use when its time to do your car. Also dont forget what I'll do to your motor when I'm building it. Sorry, I don't know how those nuts got in there. HAHAHAHA!

BMR sells a modified upper panhard rod brace and relocation kit for added exhaust clearance.

http://www.bmrfabrication.com/F-bodySuspension.htm

I was always a little hesitant to pull the brace out, but a friend on mine did it on his 30th SS convertible, and it was running 8.60@160mph with a 1.30 60-ft and no problems. Obvioulsy, the car was only driven in a straight line (more of a drag car :) ) . For street use, I'd think twice.

For street/drag that BMR brace is fine, but I'd recommend against it highly for autocrossing and especially for roadracing/track days. Geometry-wise it takes the small negatives of a PHB and amplifies them greatly.

Your an idiot for removing that brace. The bracket is not that strong without it. That panard bar transfers a great deal of side loads into the chassis even in normal driving. And like was pointed out earlier, when it fails there will be no warning and you would be lucky to not destroy your car.

The BMR piece is a good idea. But the geometry is off for stock springs and even worse for a lowered car. Idealy you bar should be level with the car sitting on the ground.

If it's a straightline car (like you said above), then take it out, it's dead weight. If you plan on autocrossing or roadracing or even driving fast around corners on the street, keep it in. Mine is in a pile along w/ my sway bars, ABS, power steering, etc.

I dont think I deserve idiot status. I was just wandering what the guys are doing that are not road racing. I could'nt give a sh*t about road racing. I am a drag racer. I dont drive fast around turns because that does nothing for me. All that matters is how fast you get to a given speed, not how fast you can take a turn mith it! I will be removing the bar but I'm going to fab up a new one for clearance. Thanks for the input.

IF your gonna drive it on the street at all, you need to keep it. Even if it's a drag only car. I wouldn't remove it. You say your removing it for exhaust clearance. Why do you need exhaust on a drag only car.

Its not a drag only car. I drive it on the street. It is not a daily driver though.

If it's a straightline car (like you said above), then take it out, it's dead weight. If you plan on autocrossing or roadracing or even driving fast around corners on the street, keep it in. Mine is in a pile . . .Wrong answer.

The vertical bracket that the brace SUPPORTS is constantly being loaded. First one way, then the other, even in straight running as the suspension moves. And even a strip-only car has to turn occasionally, as in onto the return road, into the staging lanes, pits, etc. That's called fatigue, and even though the loads I've described above aren't that big, they have a cumulative effect over time. If 'fatigue' turns into 'fatigue failure' the results really aren't going to be pretty (the failure will be where it attaches to the chassis, or it may even tear out a piece of the chassis). Actually, the factory did a pretty good job on that brace, as it's not that heavy to begin with, and it's weight that's pretty much right over the wheels that need traction anyway.

Full disclosure: 30+ years of structural analysis, including fatigue evaluations.

While I do appreciate that you did recommend keeping it for hard cornering conditions, you didn't go far enough. The possible consequences really dictate that the brace be kept at least in some form regardless of the car's use.

Norm

Hmm, guess a couple of my friends who have been running w/o them for the last year or so are in trouble. Mine is still out, still laying in a pile and still ain't going in my car. If I start to have problems, I'll reinforce it..wouldn't be anything new on my car. :cool:

LOL mine has been out of the car for over a year now.

Hmm, guess a couple of my friends who have been running w/o them for the last year or so are in trouble. Mine is still out, still laying in a pile and still ain't going in my car. If I start to have problems, I'll reinforce it..wouldn't be anything new on my car. :cool:They are at somewhat greater risk.

I'm not saying it will fail right away, next week, or even next year. Just that it will give out sooner that it would if braced in any manner at all. As a hint, I'm sure that you've more than doubled the stress where the bracket attaches to the chassis, and you can figure that doubling the stress throws away 94% - 97% of the time it takes to use up all of the available fatigue life (and then, somewhere, a crack will start). Take comfort in the fact that GM kept some conservatism in their design. But don't get too comfortable about it. You might not get a lot of warning.

Out of curiosity, when the time comes for you to sell that car, will you be freely informing all prospective buyers that this brace had been removed and the car driven that way for a while, and that the car has used up more of its fatigue life in that area than the mileage and any other descriptions suggest? We both know if you don't mention it, nobody's going to look at that area or think to ask. . . . Actually, in this age of too many lawyers, you'd better get a signed document from the purchaser acknowledging his awareness of that sort of unauthorized structural modification and its potential consequences. IOW, protect yourself.

Norm

Threre's a lot of other "unauthorized structural modifications" done to the car that would be of more concern that a panhard brace. Hell, I'm trying to figure out a way to move the panhard bar itself. It's a lot easier to put rear bars on the car if that damn bar was out of the way. :(

I was always a little hesitant to pull the brace out, but a friend on mine did it on his 30th SS convertible, and it was running 8.60@160mph with a 1.30 60-ft and no problems. Obvioulsy, the car was only driven in a straight line (more of a drag car :) ) . For street use, I'd think twice.
And to avoid even more confusion on the subject, I need to add that there were extensive modifications to the 30th SS convertible. I don't want anyone to think that deletion of the bar on an all-out drag car (never used on the street) somehow demonstrated that it was a wise deletion for everyone.

The mounting points of both ends of the panhard rod connections were dropped, both adding a new mounting pad on the axle end, and by extending the arm that holds the body end of the brace, the body arm was substantially reinforced, and alterations were made to the top connection to strengthen it. It was not an unthought-out deletion. The issues raised be Norm were considered.

http://cjcfo.fbody.com/members/injuneerzz@aol.com/GeorgeB/DCP03868a.jpg

http://cjcfo.fbody.com/members/injuneerzz@aol.com/GeorgeB/DCP03868a.jpg
Yeah, that looks pretty nicely done. But I wouldn't expect it to hold up very long in any sort of racing that uses the steering wheel.

http://cjcfo.fbody.com/members/injuneerzz@aol.com/GeorgeB/DCP03868a.jpg
Thanks for the pic Fred. That's one of the ideas I had considered. :cool: Did George ever run bars on the back of the car? If so, did this setup clear them?

Thanks for the pic Fred. That's one of the ideas I had considered. :cool: Did George ever run bars on the back of the car? If so, did this setup clear them?
He had wheelie bars on the back, afraid of getting the nose too high off the ground. But after the first pass, he realized we (actually, Steve Spohn) had the suspension down cold and it wasn't going to pull the wheels more than about 2" off the pavement. Never ran the bars again. The bars fit fine. Don't remember how long they were. S+W as I recall.

The perfect launch:

http://cjcfo.fbody.com/members/injuneerzz@aol.com/GeorgeB/IMG_0710.jpg

Come to think of it, I do remember a post by him (or about him) on his first transbrake launch. I think that's what prompted the bars. :lol: