Rear Radius Rod Angle?

[oldracer22]

I am thinking about using Speedway's Classis Rear Radius Rods 916-45110 to locate the rear end in my 1926 model T coupe. I am wondering about the front mount for the rods. I want to mount these in a triangle to a cross member to eliminate a panhard bar. The mount at the axle will be lower than the bottom of the frame. Does the forward mount for these rods need to be at such a height as to make the centerline of the radius rods level or can the centerline run up hill. What effect does the angle of the radius rod have? I'm having trouble trying to express my question in words without drawing pictures. I hope this makes sense.

 

[Kurtm333]

Rods

They do not have to be parallel with the ground but should point to the center of gravity... There length and mounting point will dictate the amount of scwat or rise you get under acceleration. This can affect traction and other things suspension related.

Pretty much I would put it were you want it and forget it unless you can make a mount with multiple mounting locations.

Kurt

 

[rex1927]

Like kurtm333 said,just mount and forget.[
They will be fine.

 

[BlueNorther]

YOU ARE CONFUSED.

even with these torque arms triangulated you will still need a panhard rod, this is not a triangulated 4-bar setup.

also the height you mount them at is a little bit critical to traction, too low and you will have a real tire smoker, and too high and the back of the car may jack itself to the moon on acceleration.

these mimic the control arms on a mid 60's Chevy pickup. they all have panhard rods.

triangulated arms are under the NASCAR Cup cars, in fact they are required to use modified 60's GM truck arms.

 

[Kurtm333]

Panard

Ya going to need a panard, watts link, or a wishbone. Unless you run a spring over the axle like in the front.

Kurt

 

[donsrods]

Until we know what kind of spring you are going to run we really can't advise you one way or the other. The spring dictates how you have to mount the radius rods, and if you need a panhard or not.

Don

 

[oldracer22]

Yeah, you're right about the panhard bar being necessary. I don' know what I was thinking. It was late when I asked this question. My main concern was about the front mounting point of the radius rods. Everything I have built in the past was either parallel 4 bars with panhard or triangulated 4 bars. I know with four bars the instant center should be at the center of gravity height or approximately the top bell housing bolt. Only 2 attachment points instead of 4 had me confused. So the centerline of the radius rods should be attached at the front to intersect the center of gravity height? By the way I am using coilovers.

 

[donsrods]

Then yes, you do need a panhard.

Don

 

[Kurtm333]

Springs

The front of the hair pins mount to the axles, the back mounts to a braket on the frame at about a parallel position to the ground. A panard or watts link is need to locate the axle side to side and the shock can mount to the axle or hairpins. Race car precision isn't probably necessary here but 3-5 degrees of camber and some toe in. Make sure nothing rubs but mostly make it look good. Good luck


Kurt