4-Bar and Triangulated Question

[DaddyT]

This is really 2 questions.
1. When doing a straight 4-bar setup, is there a minimum rod length eye to eye?
2. Triagulated- Is there a specific angle to set the upper rods at? Would it matter either way if the triangulated rods were mounted on top of the differential or further out near the backing plate.

 

[skull]

here

try here


http://www.thedirtforum.com/4link.htm

Later

 

[DaddyT]

Thanks, that was a very informative link. But I was inquirering more about the angle placement to prevent lateral axle movement when triangulated.

 

[harold]

triagulated 4 link

the upper bars should be 45deg. to center line of the vehicle. usually narrower at the rearend wider towards the front, length should be equal to lower or shorter.

 

[Bonehead]

the upper bars should be 45deg. to center line of the vehicle. usually narrower at the rearend wider towards the front, length should be equal to lower or shorter.

That is one way but not the only way. I like longer lowers, and 45 degrees makes your uppers pretty short.
Here is the one I am using on my current build.

 

[King Herald]

This is really 2 questions.
1. When doing a straight 4-bar setup, is there a minimum rod length eye to eye?
2. Triagulated- Is there a specific angle to set the upper rods at? Would it matter either way if the triangulated rods were mounted on top of the differential or further out near the backing plate.

The longer the bars the less your axle moves for and aft under suspension movement.

About 45 degrees is good for the top bars angle, but it is not exactly critical. This is all man made science, anything can vary.

You can build in anti-squat by having the top bars angle down a bit at the front, but then you diff starts to rotate a bit as the suspension moves, which makes it better to have longer bars.

I built one car with the top bars outside the diff, but my current project has them mounted together on top the housing centre. Well, slightly off centre as the housing is not centred to the frame and the bracket would have been a but awkward to make.

 

[DaddyT]

Hey King Herald, how long are the upper and lower rods from eye to eye on your rig?

 

[jtwilson]

subscribing

 

[rubi red]

Like the 4 link set up. How did you go about getting coilover spring rate?

Thinking about coilovers on all 4 corners of my Willys Pickup.

 

[DaddyT]

Ok, I'd still like to know if mounting the upper bars outboard (close to the backing plates) then attaching the other end inward to each kicked up frame rail will work. It seems to be at about 45 degrees. Will this still work w/o a panhard bar? I want to use the existing factory upper bracket if possible. Lower bars will be parallel to the frame rails. Check out the pics tell me what you think.

 

[King Herald]

Hey King Herald, how long are the upper and lower rods from eye to eye on your rig?

Top ones are 21", bottoms are 16". They'd be better a touch longer but the body design forbids that, as I wanted the rear end tucked in fairly short.

Like the 4 link set up. How did you go about getting coilover spring rate?

Thinking about coilovers on all 4 corners of my Willys Pickup.

I asked a couple of people what rate they had on their cars, took an educated guess. Mine are adjustable, from Speedway, plus I put three holes for the top end mount, so I can vary the angle a bit, which makes a difference. I think I put 170lb springs, on this.

I wish I'd bought the heim joint end fittings on the shocks, instead of poly bushes, as it would work better with the axle roll.

I also messed up because the shockers bushes were a fair bit thicker than I expected, which made my drive shaft an inch too long, which I found out after I had already shortened a stock one.... All things to plan in advance.

The bar end inserts and heim joints also came from Speedway. Tube was bought locally, some seamless 'pressure pipe' as they call it.

 

[rubi red]

Thanks - now to go look at your build thread.