custom radius arm(new question....i think)

i am preparing to strengthen the unibody and while i'm at it i am considering doing a long/radius arm suspension. My question is what should the seperation of the frame mounts for the arms be. Are the "lower" arms supposed to be parrallel or is there any advantage or disadvantage to have the frame mounts narrower than the axle mounts.

i have searched but didn't see what i was looking for, but i may have gone right passed it and not noticed. If it has been discussed before a link to the thread would be great.

Make your mounts as narrow or as wide as the arm ends you use. If it's spherical rod ends, heims, or whatever. Just make sure they are in double shear.

As for the arms themselves, they should be as parallel to the ground as possible, but remember, you don't want the axle to twist when they are at thier max up travel.

KarlVP said:

Make your mounts as narrow or as wide as the arm ends you use. If it's spherical rod ends, heims, or whatever. Just make sure they are in double shear.

As for the arms themselves, they should be as parallel to the ground as possible, but remember, you don't want the axle to twist when they are at thier max up travel.

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He's talking about the mounts in relation to each other not the width of the mounting tabs themselves.

Mount them wherever you want, but I would think if they are long enough you will get less bind if they are closer together.

Oh, sorry.

The longer the better, allows for more travel and won't make the axle fight the suspension links as it does its thing.

KarlVP said:

Oh, sorry.

The longer the better, allows for more travel and won't make the axle fight the suspension links as it does its thing.

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i know the longer the better but my question is what should the the angle between the the 2 links should it be 0 so they are parallel w/ each other or do people generally angle them and if so why

I think you are talking about the arms being a little pigeon toed or duck toed...
right?

If so, that is something that I'm interested in hearing peoples thoughts on also.

Post up

For a radius arm set-up you would have Zero bind if you could mount them both ar the same point.But thats not really possible due to the driveshaft and exhaust.Mine are about 23" Cto C!

RCP Phx said:

Mine are about 23" Cto C!

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How far apart are they at the frame side mount?

kewlkatdady said:

How far apart are they at the frame side mount?

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Uhmm,23".

so the arms go straight back?

His question was if they arms are (for example 24" apart at the axle and 22" apart on the frame end...

they would be like this \ / Is that ok?

cjovertj said:

is there any advantage or disadvantage to have the frame mounts narrower than the axle mounts.

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kewlkatdady said:

so the arms go straight back?

His question was if they arms are (for example 24" apart at the axle and 22" apart on the frame end...

they would be like this \ / Is that ok?

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No,the arms angle in,thats the idea!The factory axle mounts are about 33" Cto C!

thanks.

no, the idea is to get them as close to parrellel as possible. the angle of the arms, is called triangulation.

triangualtion resists side to side movement of the axle, the more of it, the less the axle wants to move from side to side. your steering linkage gets longer as the suspension compresses, and shorter as it uncompresses, so a drag link is added to FORCE the axle side to side as the suspension moves so you dont get any bump steer.

so now we have a steering part (drag link) forcing the axle side to side, and a suspension set up (triangualated) that resists side to side movement. we call that binding.

now, the binding that was refered to before is differnt, its simply due to the fact that radius arms suck. when you articulate the control arm that is up is longer than the one that is down, due the the radius the arm moves in. he uppers (being fixed to the lowers) start to twist the axle, the higer control arm pushes on the tube, and the lower one pulls, literally trying to twist the tube in the pumpkin.

thanks for all the info but there still seems to be alot of uncertainty
could some who has an off the shelf kit like T&T or RE or similiar measure the seperation at the axle and at the frame mounts if its not to much trouble

i am familiar w/ triangulated 4-links and how triangulation provides lateral stability and allows u to get rid of the tracbar, but i didn't think that angleing the arms would provide enough lateral stability to not need a tracbar so the axle would still move in the arc of the tracbar

it would not suprise me if my thinking is wrong so correct me if u want

I will only be using radius arms a panhard bar... HP44 swap...
so i will not have "upper arms"

tealcherokee said:

triangualtion resists side to side movement of the axle, the more of it, the less the axle wants to move from side to side. your steering linkage gets longer as the suspension compresses, and shorter as it uncompresses, so a drag link is added to FORCE the axle side to side as the suspension moves so you dont get any bump steer.

so now we have a steering part (drag link) forcing the axle side to side, and a suspension set up (triangualated) that resists side to side movement. we call that binding.

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I believe the word you're looking for is "track bar" or "panhard", not "drag link".