panhard bar relacation question

[Charles]

I need to make space for my mufflers going into place in the typical place under the rear seat area. My panhard bar identified with blue tape will be in the way as shown in the first picture which is installed per the kit. I would like to relocate the front mount of the panhard bar to the round frame tube marked with the blue tape. Will this cause any issues?

Or can I relocate it as shown on a picture I found on line with a red panhard bar directly behind the rear end to a mount? I don't know if the pics came out complete. I'll repost then tomorrow, I'm doing this from my phone today burning the midnight oil...

[Charles]

My bad, picture 1 and 2 are out of order, the first picture is how I would like to install it. Any advice would be helpful, Thanks.

[ford396]

You can relocate it as you would like per the red bar in your last picture. It would be more efficient at keeping the axle under the car. Beware though that it will make it more challenging to get an exhaust up and over the axle if it is in the way. Also ensure that the new fabricated mount on the chassis is well supported. There is a lot of force fed into the panhard bar.

Your proposed new location is also higher in the chassis than your old mount. This will have a tendency to loosen up the rear of the chassis handling wise. If it is a street car, move it up where you propose and drive it. If it is a track car, you will need to rebalance the rear of the car with different springs or change the front roll center to rebalance.

[ford396]

This is the rear of my Ventura. A work in progress.

[Charles]

Thanks for the input ford396. I'll look into relocating it behind the rear end. Wow, that a crazy curve on yours, pretty creative.

[Carl @ Chassisworks]

Hey Charles, you don't actually have a Panhard bar. You have a Track Locater. Chris Alston introduced this back when King Arthur was ruling the round table. Some people call them 'diagonal links.' Both are lateral locating devices, similar in function to a Watts link or Satchel link. A panhard bar runs parallel to the axle centerline. If you convert to a Panhard it needs to be a minimum of 30" long assuming 5" of travel where the bags are mounted. If they are travelling more like 7-8 inches then you should probably make it closer to 36". The drawback to a panhard is that the suspension will move side to side as it goes through it's travel. The shorter the bar, the more extreme this swing will be.

The thing that surprises me here is that you have ladder bars. Have you driven the car yet? I'm betting it swings donuts pretty well. Ladder bars are essentially a swingarm, or hinge, on the back of the car. They are designed to go up and down and keep the car flat for equal traction to both tires in a straight line. To go around a corner you need some body roll so there is adequate weight transfer to plant the outside tire.

[ford396]

Carl

I respectfully disagree with a couple of the points that you have made.

A panhard bar runs parallel to the axle centerline.
I disagree with you on this point. When I took the panhard bar on my super late model and moved the chassis mount forward about 11" it is still a panhard bar.

The drawback to a panhard is that the suspension will move side to side as it goes through it's travel. The shorter the bar, the more extreme this swing will be.
Definitely agree with you on this. Make the panhard as long as possible.

To go around a corner you need some body roll so there is adequate weight transfer to plant the outside tire.
I also disagree with you on this point. Weight transfer is not a factor of body roll. When I run a car on bump stops or soft spring and a very large sway bar, I may have zero degrees of body roll but it will still plant the outside tires and transfer weight.

Bob

[Carl @ Chassisworks]

Charles,
In reading back through this thread I realized I didn't directly answer your question. You were asking if you could move the mounting point for the track locater to the round crossmember with the "x" and piece of masking tape. The answer is no, it can't go there. This mounting location would cause the suspension to bind. Putting a bar behind the housing, such as a Panhard bar, would likely be your best bet. Make it as long as possible.

Bob, you're right that I could have phrased both of my comments better. Ideally, a panhard bar runs perpendicular or close to perpendicular to the frame. I'm not denying that other positions can be functional. OEMs will offset the bar for packaging purposes. With either style bar, panhard/track locater, the further away you move from the ideal alignment, the more bind is introduced. That doesn't mean it won't work, it's just not ideal.

I didn't state what I meant about ladder bars on the street very well at all and I do not disagree with what you said about body roll. Suffice it to say, they're not ideal.

[Charles]

Thanks for the input guys. So, can I use my track locater as a panhard bar? It is 36" long and 3/4" thick. As long as I set it parallel to the axle at ride height it should be good correct? I really don't know why I went with this ladder bar set up, my buddy helped me build the rear suspension for air bags on this car and this is what he put together. The entire back half of the car is heavy steel tubing along side of the unibody. We did this set up about 7 years ago when I first bought this car and was not familiar with any other suspension set ups that would work with air bags. That and I was not familiar with the pro-touring scene. Wish I knew more back then.

[ford396]

Charles: yes you could use your existing link; however, I feel it is too light. I would prefer to use something in the 1" - 1 1/4" range w/ a heavy wall. There is a lot of force fed into this bar.

At 36" long, it is a good length. Attempt to keep the height somewhere in the 10"-13" range and you should be good. Since you are fabricating brackets anyway, build a little adjustability into them so that the bar can be slid up and down a little.

Bob

[Charles]

Sounds good. I will do that. Thanks for the input, now back to burning some steel. Thanks.