Panhard bars??? (1 Viewer)

[Tank5]

I have this project, installing 80 suspension on a 45 series frame. The front panhard bar is the last piece to finish the suspension placement.

I researched and talked with a couple people about setting up the panhard. They all suggest trying to make it equal to or within 2 inches of the drag link. Haha this seems pretty much impossible on an 80 setup.

I got to thinking and the 80 front panhard is no where near this. From a stock 80 the drag link measures 43 inches center to center and the panhard measures 31.75 inches center to center. The pan hard is about 73% the length of the drag link.

What is it about the 80 suspension that makes this work without steering issues?

At this point I am prepared to match the panhard link length un percentage and apply it to my setup. I want to make sure I don't miss anything first.

 

[SNLC]

Extremely ridge radius arms.

Cheers

 

[matzell]

I think matching the angles is more important than the length. The flatter the better to control bump steer. You want the panhard and draglink to be in the same plane. You can mount the upper end outside the frame to gain some length. If this is a low speed vehicle it is not that bad. On my 4500 car racing at speed it is more important when going through the whoops!

 

[Tank5]

I think matching the angles is more important than the length. The flatter the better to control bump steer. You want the panhard and draglink to be in the same plane. You can mount the upper end outside the frame to gain some length. If this is a low speed vehicle it is not that bad. On my 4500 car racing at speed it is more important when going through the whoops!

Thanks, this is exactly what I did. Last night as a stared at the front suspension I realized the panhard mounts could only fit a couple ways. I made the panhard as long as I could but made sure it matches the drag link. I cycled the suspension and it will clear everything, so I am going to run with it an see how it turns out.

My rig is not a race car so this set up should be ok. Time will tell.

 

[cruisermatt]

@nukegoat wrote a Excel calculator to show the amount of bumpsteer caused by misalignment as a result of different length/position panhard/drag link - maybe he can post it and you could input your data to see what the result would be

 

[Tank5]

That would be great! @nukegoat please do share.

 

[peesalot]

What cruisermatt said --- you have to match the lateral movement of the axle as the panhard travels thru it's arc with the lateral movement of the drag link, it may be same length & angle, it may not, depends on on attachment points, running it thru the calculator gets you a starting point, the drag link attachments are known so start there and design the panhard to match using the above mentioned calculator to determine ideal length and location of attachment points, getting it right matters, too many panhard bracket failures from sloppy attempts, getting the panhard geometry correct is a big deal IMO.

 

[Tank5]

What cruisermatt said --- you have to match the lateral movement of the axle as the panhard travels thru it's arc with the lateral movement of the drag link, it may be same length & angle, it may not, depends on on attachment points, running it thru the calculator gets you a starting point, the drag link attachments are known so start there and design the panhard to match using the above mentioned calculator to determine ideal length and location of attachment points, getting it right matters, too many panhard bracket failures from sloppy attempts, getting the panhard geometry correct is a big deal IMO.

@nukegoat was nice enough to share his calculator with me. Thank you!

I played with different options measuring from ride height. My build is not complete but the motor is sitting on the chassis with the cab but nothing else on the front, so I pulled the front down another inch with a ratchet strap to try and make up for the missing weight.

There is not a lot of room to make adjustments and even when I play with the numbers I do not gain much. This is where I am at. How bad is this?

Tomorrow I will take all the measurements from a stock 80 to get a comparison for what I am trying to achieve. This will help answer my own question.

 

[nukegoat]

@nukegoat was nice enough to share his calculator with me. Thank you!

I played with different options measuring from ride height. My build is not complete but the motor is sitting on the chassis with the cab but nothing else on the front, so I pulled the front down another inch with a ratchet strap to try and make up for the missing weight.

There is not a lot of room to make adjustments and even when I play with the numbers I do not gain much. This is where I am at. How bad is this?

Tomorrow I will take all the measurements from a stock 80 to get a comparison for what I am trying to achieve. This will help answer my own question.

View attachment 2419407

Well your drag link and track bar are fairly flat to start with so compensating with unequal angles doesn't give you much in the way of options.

Honestly IMO your track bar is just flat out way too short. You need to figure out a way to use a longer one. I wouldn't enjoy driving that setup unless it had virtually no suspension travel.

 

[nukegoat]

What cruisermatt said --- you have to match the lateral movement of the axle as the panhard travels thru it's arc with the lateral movement of the drag link, it may be same length & angle, it may not, depends on on attachment points, running it thru the calculator gets you a starting point, the drag link attachments are known so start there and design the panhard to match using the above mentioned calculator to determine ideal length and location of attachment points, getting it right matters, too many panhard bracket failures from sloppy attempts, getting the panhard geometry correct is a big deal IMO.

I don't know who you are but you're spot on in my book

 

[Tank5]

What cruisermatt said --- you have to match the lateral movement of the axle as the panhard travels thru it's arc with the lateral movement of the drag link, it may be same length & angle, it may not, depends on on attachment points, running it thru the calculator gets you a starting point, the drag link attachments are known so start there and design the panhard to match using the above mentioned calculator to determine ideal length and location of attachment points, getting it right matters, too many panhard bracket failures from sloppy attempts, getting the panhard geometry correct is a big deal IMO.

Well your drag link and track bar are fairly flat to start with so compensating with unequal angles doesn't give you much in the way of options.

Honestly IMO your track bar is just flat out way too short. You need to figure out a way to use a longer one. I wouldn't enjoy driving that setup unless it had virtually no suspension travel.

I spent some time today trying to find ways to extend the panhard length. I found the best way to do this would be to use the stock 80 mount on the passenger side axle I will have to extend the driver side frame panhard mount considerably to keep the panhard at the same level at the drag link. If I do this I should be able to accommodate a 31.5 to 31.75 panhard which is the stock 80 length. This it the new chart showing these changes.

Here is the set up I am working with. There is not a lot of room to work with between the axle and tie rod.

 

[Tank5]

I started this project trying to match the 80 suspension as best I could. To keep with that idea I measured and charted the a stock 80 series for comparison to give me a target to shoot for.

This is the stock 80 chart.

 

[nukegoat]

Yeah packaging is tough but I believe in you

 

[Tank5]

Just show where I ended up. I have the panhard as long as I can make it and that came out to 29 inches. It will be adjustable but fractions of inches don't seem to make much a difference on the calculator.

I set the Passenger mount back to the original 80 series position. The driver side mount had to be extended a lot to match the drag link angle. I will have to reinforce it significantly. The panhard I will have to get bend with a big half loop in it to go over the front diff. The whole set up seems like an experiment. I am going to go with it and if it doesn't work well then I come back to it. Thanks for everyone's help and comments.

 

[matzell]

do you have room to kick the panhard outside the frame, looks to be leaning inward. It needs to go outwards.

edit. you can mount it just under the frame at the top hole, but a bend in the panhard if you are using .250 wall tube, and then it should travel in the same plane, If I was smarter on a computer I would draw you a picture. the one on my race car has a bend in it and has not let me down in 6 years of abuse.

 

[White Stripe]

Looks like in this instance a Saginaw box between the frame horns would give more room.

 

[Tank5]

do you have room to kick the panhard outside the frame, looks to be leaning inward. It needs to go outwards.

edit. you can mount it just under the frame at the top hole, but a bend in the panhard if you are using .250 wall tube, and then it should travel in the same plane, If I was smarter on a computer I would draw you a picture. the one on my race car has a bend in it and has not let me down in 6 years of abuse.

The space between the tierod and axle housing is narrow, so the panhard operates directly over the front ends of the radius arm brackets. I angled the frame side bracket inward because if I didn't it would contact the radius arm bracket on compression. If I angled the bracket outside the frame the panhard would contact the radius arm on compression. At the current ride hight I have 4 inches of compression before the bump stops hit. If I add two inches to the bump stops I could probably extend the bracket outside the frame.

I have been considering raising the spring hats off the axle to create more clearance with the steering arms. Next week I should have a set of 70 series coils. I will use them to mock up with to see if find some additional space to work with.

The more I look at it the less I like it. I will keep playing with it.

 

[Tank5]

Looks like in this instance a Saginaw box between the frame horns would give more room.

The only defference I see that a Saginaw box would give me is more space on the outside of the frame to attach the mount. It wouldn't create more room for the panhard bar that I can see.

 

[Tank5]

I have come up with another option. Need your thoughts.

If I space the bottom spring hats up 2 inches I can move the stock axle side panhard mount up 2 inches which allows me to move the frame side mount up two inches and angle it to the outside of the frame. This would allow me to increase the panhard bar length to around 33 inches.

70 series stock springs are about 2 inches shorter than 80 stock springs. I am thinking this maintain the ride height with the spring hats spaced up 2 inches.

Anyone see any issues with placing the spring hats this high above the axle?

 

[matzell]

Can we get a pic from the drivers side showing the path of the panhard to the axle? I was referring to the bend in the panhard as going down from the frame then across to the axle. It would be a straight shot from the axle to the frame but not go forward or backwards. This way the upper mount could be higher. Almost like a "L" but not that extreme.