Panhard Bar Brace Design

[DocB]

I am planning on installing a PHB Brace and would like to know if there is any difference in structural rigidity in the round versus rectangular style (in cross section). This also pertains to the end flanges on the two types.
This is for a dedicated road course car, see sig., and axle centering is my primary concern. I have reviewed most of the braces offered by vendors and discussion of or reference to a specific type or brand with tech appreciated.

 

[Sky Render]

Are you talking about the bar itself or the brace that goes "above" it?

 

[kevinatfms]

dont worry about the brace, "upgrading" to a beefier bar has shown no real improvement and the money is better spent elsewhere.

FWIW, most of the factory ford race programs still run the stock PHB brace and just upgrade the PHB to an adjustable unit.(been said a few times before)

EDIT: is this an actual FR500S or a 08 GT with FR500S bits?

 

[Sky Render]

If you're only worrying about centering the rear axle, pretty much any adjustable panhard bar will work. I like Whiteline's because of their bushing design, but if it's a track-only car, you might want to look into one that uses only rod-ends, like BMR.

 

[leviathon]

Freedom Racing has a good panhard bar as well. You can either get heim ends or poly bushings and they dont break your wallet either. Tad is a great guy to work with.

 

[BMR Tech]

I am planning on installing a PHB Brace and would like to know if there is any difference in structural rigidity in the round versus rectangular style (in cross section). This also pertains to the end flanges on the two types.
This is for a dedicated road course car, see sig., and axle centering is my primary concern. I have reviewed most of the braces offered by vendors and discussion of or reference to a specific type or brand with tech appreciated.

Boxed tubing is stronger than tubular/round tubing.

Is it enough to matter? Probably not.

 

[leviathon]

I have yet to even hurt the Fixed LCA's you guys have

Boxed tubing is stronger than tubular/round tubing.

Is it enough to matter? Probably not.

 

[DocB]

Fellas,

Thanks for the replies and info. Greatly appreciated.
I will look again at the braces from the vendors mentioned.
Will let you know what I decided.
Structual engineering says that the boxed type should be stronger, but I didn't like the end flanges on the ones I looked at.
This is one of the minor mods planned for this Winter.

Car is an actual FR500S, #527. Mostly stock, but some minor mods, like the hood for cooling, some custom damper tweeking, and an awesome tune. To me, it is the best car I have ever driven on track.
Everytime I unbuckle and get out of the car I have a smile glued on my face for about 20 minutes.

 

[BMR Tech]

If you are referring to our end "flange" what is it exactly that concerns you?

 

[Sky Render]

I really don't think that brace makes much of a difference. If you bent the stock one in an off-track excursion or something and need another, I'll sell you a stock one cheap. Otherwise, Whiteline, BMR, and Evolution all make braces that are more than adequate.

 

[DocB]

Kelly,

I like the box tube design on the BMR brace, but I like the mounting end flange design on this one:

http://www.steeda.com/store/steeda-heavy-duty-panhard-bar-brace-for-ford-mustang.html

I am not against modifying a part (it seems the MO for us), but as of late I am trying to buy parts that I can just "bolt on" and save a little time. Am trying to get out from under and actually into the cars.
It's getting a little old to have to "fix" almost every part the we buy brand new.

 

[BlackDragon]

Kelly,

I like the box tube design on the BMR brace, but I like the mounting end flange design on this one:

http://www.steeda.com/store/steeda-heavy-duty-panhard-bar-brace-for-ford-mustang.html

I am not against modifying a part (it seems the MO for us), but as of late I am trying to buy parts that I can just "bolt on" and save a little time. Am trying to get out from under and actually into the cars.
It's getting a little old to have to "fix" almost every part the we buy brand new.

I have this one on my car and its a nicely built piece.

 

[Norm Peterson]

Assuming adequate end details (I think there's a little kink on the driver side end) I really can't see it making much difference whether you choose a round or a square tube cross section.

Ignoring a little bending local to the little kink, the brace is primarily loaded in either tension or compression. Tension, you don't worry about because the actual [Force] / [Area] stress is much lower than the material tensile stress allowable and it can't buckle. Compression is a little more involved and has a bit less margin due to buckling considerations, but for dimensions typical to this sort of brace the compressive stress allowable for either shape is still comfortably higher than the stress caused by the cornering loads.

There is the matter of impact loading (typically, 2 times the maximum static load), but there's even sufficient margin for that. This would involve much harder hits than FIA curbs, more like the wheel hitting a fixed object during an agricultural or a tall curb out on the public streets.

About the only legitimate way to fail the brace would necessarily involve failure of the passenger side PHB attachment post by a really hard strike by the passenger side rear wheel up against something solid, probably hard enough to visibly bend the wheel. IOW, failure of a PHB brace alone is very unlikely. Short of your installer using it as a jacking point, anyway.


Norm

 

[Sharad]

Boxed tubing is stronger than tubular/round tubing.

Is it enough to matter? Probably not.

Every engineering write up I've ever read says the opposite. Square/Rectangular isn't stronger unless it's bigger than the round tubing, and then it's not a pound for pound comparison.


Anyway, here's my specific recommendation for the OP.

Panhard Brace
http://www.uprproducts.com/mustang-pan-hard-brace-05.html

PHB
http://www.uprproducts.com/mustang-pro-series-adjustable-pan-hard-bar-05.html

 

[BMR Tech]

Every engineering write up I've ever read says the opposite. Square/Rectangular isn't stronger unless it's bigger than the round tubing, and then it's not a pound for pound comparison.


Anyway, here's my specific recommendation for the OP.

Panhard Brace
http://www.uprproducts.com/mustang-pan-hard-brace-05.html

PHB
http://www.uprproducts.com/mustang-pro-series-adjustable-pan-hard-bar-05.html

Considering both weight and strength, tubular is an excellent choice, and is stronger at a given weight.

Rarely would you see that though. If you see a boxed design from us, I can assure you that it is stronger than another part for the same application, that is tubular, but that tubular part will be lighter.

It is very similar to how many companies claim their parts are lighter AND stronger due to them being chrome-moly, but typically, they are either one or the other. (due to the common size tubing available to purchase by the "mile")

For this application, it was common sense for us when designing this part. We gave it a rectangular design that will provide the best clearance for the exhaust. We have a stepped mounting bracket on the driver side, with a slight bend on the passenger side.

 

[DRock]

Kelly,

I like the box tube design on the BMR brace, but I like the mounting end flange design on this one:

http://www.steeda.com/store/steeda-heavy-duty-panhard-bar-brace-for-ford-mustang.html

I am not against modifying a part (it seems the MO for us), but as of late I am trying to buy parts that I can just "bolt on" and save a little time. Am trying to get out from under and actually into the cars.
It's getting a little old to have to "fix" almost every part the we buy brand new.

I run the BMR on my car for a little over 30k now in all kinds of different scenarios. Road racing autocross, and DD. Have had no problems with it. Did it make a big difference? COuldnt tell ya since i did other things at the same time but since its only $100 and i was in their anyway i figured what the hell