I just started my ‘33 HR and, for the life of me, I can’t figure out what this vertical mount is for on the rear of my frame. I’m sure as I get into the build I might figure it out but my frame was ordered for a 4 link setup. Rather than rack my brain and spend any more time on the web looking, I figured I show my ignorance and just ask.
That is for the Panhard Bar.
It's part of the frame on all solid axle cars.
On the Roadsters and 289 FIA cars, that bracket it is a bolt on item.
I'd recommend keeping it because you may want to upgrade to the 3-Link down the road.
Panhard bar is a 3-link thing, as others have mentioned. 4-link doesn't have one. Seems a little strange they would have a 3-link panhard bar mount on a 4-link chassis. Not sure it's right, but then don't know for sure.
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Jeff, The four bar suspension of 90's Mustang design is flawed for high performance driving. The upper arms oriented on the diagonal **** the rear axle when side loaded. The fix is a panhard bar that does not let the axle displace in yaw. Now you need a mount bracket on the axle housing, and a bar. You will be glad that you did.
jim
Ha! the editor did not like the word Koch, or something like that. The specific issue is when high cornering loads push the chassis to the side, one upper arm gets shorter and the other gets longer. The short arm pulls that side of the axle forward and the opposite arm pushes the axle aft. Good enough and cheap enough for Mustangs.
Maybe FFR came to their senses making the four bar more suitable for high performance driving. Maybe they included the panhard bar too.
Jeff, The four bar suspension of 90's Mustang design is flawed for high performance driving. The upper arms oriented on the diagonal **** the rear axle when side loaded. The fix is a panhard bar that does not let the axle displace in yaw. Now you need a mount bracket on the axle housing, and a bar. You will be glad that you did.
jim
Ha! the editor did not like the word Koch, or something like that. The specific issue is when high cornering loads push the chassis to the side, one upper arm gets shorter and the other gets longer. The short arm pulls that side of the axle forward and the opposite arm pushes the axle aft. Good enough and cheap enough for Mustangs.
Maybe FFR came to their senses making the four bar more suitable for high performance driving. Maybe they included the panhard bar too.
He'd be even better off to just change it over to the 3-link setup with the panhard bar, way better handling than the Mustang 4-link.
Panhard bar is a 3-link thing, as others have mentioned. 4-link doesn't have one. Seems a little strange they would have a 3-link panhard bar mount on a 4-link chassis. Not sure it's right, but then don't know for sure.
before you cut it off, call FFR and see if it is supposed to be there. I'm not aware of any differences between the 4 link and 3 link frames but the guys that know are at FFR.
before you cut it off, call FFR and see if it is supposed to be there. I'm not aware of any differences between the 4 link and 3 link frames but the guys that know are at FFR.
My friend Dave built a 2nd Generation Hot Rod and it has provisions for both the 3-Link and 4-Link solid axel configurations.
before you cut it off, call FFR and see if it is supposed to be there. I'm not aware of any differences between the 4 link and 3 link frames but the guys that know are at FFR.
I am not experienced enough to identify which suspension configuration is in the OP's photos. It is possible the frame is actually set up for the three-bar, not the four bar.
I would not cut anything off until you have assembled the car and evaluated the handling. Cutting is easy, putting it back, not so much.
jim
The 4-link uses the Fox/SN95 Mustang suspension geometry AFAIK, which doesn't use a panhard bar, so that frame member would be unnecessary if that is the suspension being used.
Now, if FFR screwed up and sent the wrong frame, or Cudajeff didn't actually order the 4-link frame, then no, don't cut it off.
But, I sure wouldn't wait until final assembly of the rear axle to find out something is wrong.
But, IMO, he would be better off if the frame actually is for the 3-link, as it is a better handling option than the Mustang 4-link setup.
Then he would just need to add the mount to the axle for the single top link of the 3-link and add the panhard bar.
Cudajeff needs to, BEFORE doing anything else, find out what he actually has.
The Hot Rod 4 link already includes the Konis and coilovers. I'd encourage you to go ahead and spend the extra few hundred bucks to upgrade it to a 3 link.
BTW, aren't you the guy who recently introduced himself and said you planed to build a Speedstar for charity with a late 2022 delivery? Did you change plans and go with a '33?
Thanks for all the input and advice. I will reach out to FFR and get some clarification. I’m not cutting anything off until I know exactly what direction I wanna go.
Yes Jeff I am the guy building this car for charity. I’ll explain... my charity ordered a Speedstar in April with a November delivery date and while I was waiting, I was gathering parts and found a rear differential that was perfect just 3 hours away. So I made the 3 hour drive to get it last week and when I got there the gentleman selling it had a ‘33 HR sitting in his shop still on the pallet and all the parts still in the boxes. He’s had it for a couple months and hadn’t started it. We got to talking and I told him about the charity building the Speedstar so we could auction it off and he offered to sell me his 33 at a significant discount so the charity could benefit from his generosity. I couldn’t believe my good fortune. I shook his hand drove back to Houston, got a cashiers check and went back 3 days later and picked it up. This is part of the confusion about the frame. I was told it was setup for a 4 link but I didn’t actually order it so I’m still trying to figure out exactly what I have.
Thanks for everyone’s help. I’m sure to have many more questions and will take all the advice I can get.
Thanks for all the input and advice. I will reach out to FFR and get some clarification. I’m not cutting anything off until I know exactly what direction I wanna go.
Yes Jeff I am the guy building this car for charity. I’ll explain... my charity ordered a Speedstar in April with a November delivery date and while I was waiting, I was gathering parts and found a rear differential that was perfect just 3 hours away. So I made the 3 hour drive to get it last week and when I got there the gentleman selling it had a ‘33 HR sitting in his shop still on the pallet and all the parts still in the boxes. He’s had it for a couple months and hadn’t started it. We got to talking and I told him about the charity building the Speedstar so we could auction it off and he offered to sell me his 33 at a significant discount so the charity could benefit from his generosity. I couldn’t believe my good fortune. I shook his hand drove back to Houston, got a cashiers check and went back 3 days later and picked it up. This is part of the confusion about the frame. I was told it was setup for a 4 link but I didn’t actually order it so I’m still trying to figure out exactly what I have.
Thanks for everyone’s help. I’m sure to have many more questions and will take all the advice I can get.
Ah...
Well, that guy may be calling the 3-link frame a 4-link because the panhard bar is basically a 4th link.
Look for the mounts for the front end of the upper control arms and see what's there, that would tell what the frame is set up for.
It is used on any live axle regardless of the longitudinal link configuration, for lateral control.
We used Panhard Bars and Watts links on road racing muscle cars and "stock cars" with leaf springs because the lateral G-forces were more than the leaf springs could constrain.
jim
It is used on any live axle regardless of the longitudinal link configuration, for lateral control.
We used Panhard Bars and Watts links on road racing muscle cars and "stock cars" with leaf springs because the lateral G-forces were more than the leaf springs could constrain.
jim
Not necessarily used on "any live axle" because the fox/sn95 4-link suspension that the FFR 4-link is based on does not use a panhard bar.
That is why the upper links are angle outward from the center, to provide lateral control by triangulation without the panhard bar.
Watts link is the ultimate live axle lateral location device since it always keeps the axle centered, where the panhard bar pulls the axle from side to side as the suspension travels through its arc.
Not necessarily used on "any live axle" because the fox/sn95 4-link suspension that the FFR 4-link is based on does not use a panhard bar.
That is why the upper links are angle outward from the center, to provide lateral control by triangulation without the panhard bar.
Watts link is the ultimate live axle lateral location device since it always keeps the axle centered, where the panhard bar pulls the axle from side to side as the suspension travels through its arc.
You got me there Ltngdrvr. Panhard bars are not manditory, and indeed, millions of cars do not have them.
jim
BTW The trig equation for lateral displacement of a live axle traveling 3.0 inches with a 48 inch panhard bar is:
m = r - sq root of r squared - c squared divided by 4
Saving you the calculator task, the answer is 0.03 inches lateral displacement, about the same as a spark plug gap.
You are right again.
jim
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Originally Posted by Cudajeff
