79 K5 Prerunner "Lucy"

[blazinzuk]

Yes 3 link 2 lowers one upper. Harder time fit for sure.

Radius arms have their place. On my Jimmy I will probably do radius arms but I am not after killer flex or high speed awesomeness. After a smooth ride for a daily driver/ expo rig/ rockcrawler/ dunerunner/ mud / snow on and on an on. I am also just using 2 heims bushings on the axle end.

How much overall lift are ya after

 

[sreidmx]

Very cool, I suppose my needs are the same but I like to go fast and jump it etc, basically what I can get away with and not break.
If I could only have it 2 or so inches taller than stock I'd be happy. I need to see how much up travel that puts me at. Lower the better, I'll carve the fenders out for clearance.
I'll look at lowering my pivots so that puts me lower in the arc so it gains more caster than it does now

 

[82355]

I am not really worried about ground clearance at this point, the transfer case hangs down 6 inches below the frame so as long as I stay around that I am ok.

Why do you have your transfer case dropped?

Martin

 

[jekquistk5]

Why do you have your transfer case dropped?

Martin

Yes please fix those spacers.

 

[sreidmx]

Dudes it was that way when I got it, I assume that was with the lift originally. They will disappear I promise..

 

[sreidmx]

And it's dropped cuz that's cool..

 

[sreidmx]

Uh changes are coming.. New developments!

 

[blazinzuk]

Awesome now switch to a 3 link cause it will make it more better with those !!!

 

[sreidmx]

Lol you beat me to it.. Either 3 link with centered lower link or a parallel type four link ....

 

[sreidmx]

Killer Whale REV 2.0

So had some crazy changes over the last week. When I discovered that it was nearly impossible to have radius arms, a low ride height and have my caster in check I basically gave up on the whole idea of a radius arm.. For me I want the stability at the bottom of the travel so when I land off a jump or something it goes straight and is stable.

I did some searching on 3 links and didn't really come up with something I liked, I still wanted the roll stiffness a radius arm adds but not the sloppy noodle the three link can act like. The fact the parallel 4 link is like a radius arm in that respect and the idea I could control antisquat and roll steer sounded like a great idea.

I did a bit of research to see where people mounted the control arms. Of course ORD has a kit and I gathered some basic measurements from the truck and stuck it into the calculator.

Well I must be way off because my setup yields 140% antisquat and the caster changed just like a radius arm. The packaging issues with this are also a nightmare because the trans crossmember is in the way etc.. I am going back to the drawing board on this.

 

[sreidmx]

Let's just say I fixed it..

 

[Deuling]

Pinion angles look a bit off on bump and droop. Looks like its pointing down on bump, and really steep on droop....


Maybe just the pics?

 

[sreidmx]

At droop it's got some caster so it will have a worse angle for a cv but better for single cardan. I'll see how it does. I rarely use 4wd anyway so I might not notice the vibes it will cause with a cv. By the way this is getting limited to 13-14 inches of travel mostly because I don't want the axle to swing 3.5 inches to one side and if I limit the travel it reduces that a lot.
This gains caster at bump and stays static down to where you see it. I saw it gain 6 degrees at the very bumped out area and it happens quick like the last 3-4 inches because the upper is short.

 

[sreidmx]

Oh and this is setup for 56% antisquat and almost 0 roll axis! Pretty awesome I think should be really neutral..

 

[jekquistk5]

Oh and this is setup for 56% antisquat and almost 0 roll axis! Pretty awesome I think should be really neutral..

You are not gonna like that 85-100% Anti dive then slightly neg for roll. Unless its not road worthy then go for it.

 

[sreidmx]

Killer Whale REV 2.0

Why do you say that? I'm curious.

 

[jekquistk5]

Slightly neg on roll to reduce/help bump steer. You really can't eliminate it unless you go full hydro. 85-100 is pretty much the standard for Anti squat/ anti dive, but you may not notice a difference either way. I forgot you are building a go fast truck, not a crawler/ trails rig.

 

[sreidmx]

I wanted lower squat mainly to allow the front to absorb some of bumps at speed under braking. I know springs and shocks have a role but the chassis should be more compliant as a result :fingers crossed: I have been under the guise that bumpsteer is a result of the different arc of the trackbar and draglink?

 

[sreidmx]

I have researched this a bit and found that for the solid axle a little either way on the roll axis inclination isn't going to make or break my setup. I reduced is a lot by triangulating the links a bit. It would be nice to be slightly under steer but I feel a redesign wouldn't merit this. Just to much other stuff, I already have a pretty high RC so this should help reduce total. Body roll and roll steer plus the fact there may be a sway bar at work negates it's completely imho.

 

[jekquistk5]

I wanted lower squat mainly to allow the front to absorb some of bumps at speed under braking. I know springs and shocks have a role but the chassis should be more compliant as a result :fingers crossed: I have been under the guise that bumpsteer is a result of the different arc of the trackbar and draglink?

Sorry was on my phone in the car and meant to type roll steer. Yes you are correct in the drag link angle and length to match the panhard helps. Staying neutral/ slightly negative roll makes for a true tracking(no wondering) and makes it predictable in the corners. When you get further away from neutral(zero) it makes it less and less predictable.