3 link front...

[hellbilly04]

Wow thanks for the info...It's starting to all make sence now!. You should write a book on 3 links dude...:worship:

Thanks again, Once I have it all together I'll post some pics of it...

Billy

I would at least try to increase it on the axle side, then...that should still help with the numbers a little bit. That will also help with keeping the joints from wearing as quickly (more separation = less force experienced in the link).

Brake dive is what happens when you jam on the brakes and the vehicle weight transfers to the front. The amount that this weight transfer compresses the springs is partially described by the AS% number - the higher this number is, the more resistant to brake dive the vehicle will be. SOME brake dive is a good thing, which is why a lot of people will shoot for the 50-70% range for that value. There's no "optimum" number here.

That's your center of gravity. There's a few different procedures you can do to obtain a real measurement, but a good approximation to start with is somewhere between the camshaft height and the top bellhousing bolt height. (this is height from the ground).

 

[Weasel]

they already makes books, he's just read them..

One the brake dive if it's too low you could actually lift the rear tires when braking hard. Looks cool but thats about it.

 

[Goatman]

If you raise the upper arm on the axle it will give you more seperation and less brake dive (higher AS number), and should be simple to do. I wouldn't worry about the frame side.

 

[XJ_ranger]

they already makes books, he's just read them..

One the brake dive if it's too low you could actually lift the rear tires when braking hard. Looks cool but thats about it.

:eyes:

 

[Weasel]

wondering when that was gonna get posted...lol. Our car last year did just about the same thing.

 

[Roxtar]

easiest place for the mounts.

:roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao: :roflmao:
There is no "easiest" place for the mounts.
Only hard, harder, and truly hateful.

 

[Ghost]

Now that winter closures are here and Christmas is done I need to get back on figuring this all out. I was looking at the Sprung Mass CG 'Z', how do I calculate that? I looked at a COG link in the text but am unsure of how to proced. Did you guys weigh your jeeps like they listed? Or estimate it. The calc lists this for a rear, does it matter that I am trying to do a front? (I would think not.)
x is the length of the arms?
y the distance between the arms at the mount points?
z is the distance of the mount points front and rear from the ground?

Is all this right? Just trying to figure out where where I get all these numbers from....

 

[hellbilly04]

Hey Ghost,

First off Happy B-day to ya!

COG (center of gravity) I was told a good place to get that measurment is at the cam, that where I got mine.

Yes to your answers below. Good luck

Billy


x is the length of the arms?
y the distance between the arms at the mount points?
z is the distance of the mount points front and rear from the ground?

Is all this right? Just trying to figure out where where I get all these numbers from....[/quote]

 

[vetteboy]

x is the length of the arms?

No...X is a measure of that mounting point to the axle centerline, as viewed from the side.

y the distance between the arms at the mount points?

Y is HALF the distance. Basically the distance out to the mounting point from the centerline of the vehicle.

z is the distance of the mount points front and rear from the ground?

Yep.

As mentioned, the camshaft height (or upper bellhousing bolt) is a decent place to start with for a CoG estimate. Being off by a few inches really won't change the numbers that much anyway.

 

[Ghost]

So y is the distance from the center of the vehicle to the mount point?
Or half way between the frame rails to the moutn point?

Ok so the axle end is 2.5 on his lower links because it is behind the axle? I think it is getting clearer. TY for the Bday wishes too.

 

[vetteboy]

So y is the distance from the center of the vehicle to the mount point?
Or half way between the frame rails to the moutn point?

Ok so the axle end is 2.5 on his lower links because it is behind the axle? I think it is getting clearer. TY for the Bday wishes too.

Well, I'm guessing your lower links are going to be symmetrical...so it's wherever the center is. Typically it's in the middle of the vehicle.

2.5 sounds about right for the axle end.

 

[Ghost]

What about the panhard bar x,y,and z?

 

[vetteboy]

Exactly the same...even though it's a little weird to think about. Here's my specs & chart for my front suspension so you can see how the numbers translate...

 

[Ghost]

I don't think this image is going to be easy to read but I will try.

If you can read this what do you think? I think my CG is too high by 2.5" Which changes anti squat considerably to 102.18%.

 

[XJ_ranger]

My upper arm is approx 4" longer than my lowers...

this works really well because when the front axle droops out, the pinion rotates up, and doesnt bind out the driveshaft till really low in the travel...

you might consider the effects of a short upper and what that will do to your driveshaft...

also - a 26" long trackbar? you cant make it any longer?

the longer the trackbar, the larger the arc the axle moves in, the less side to side movement for the same travel... I managed to get my trackbar to something like 32" long...

 

[Ghost]

My upper arm is approx 4" longer than my lowers...

this works really well because when the front axle droops out, the pinion rotates up, and doesnt bind out the driveshaft till really low in the travel...

you might consider the effects of a short upper and what that will do to your driveshaft...

also - a 26" long trackbar? you cant make it any longer?

the longer the trackbar, the larger the arc the axle moves in, the less side to side movement for the same travel... I managed to get my trackbar to something like 32" long...

Wow, did not know that a long TB was desirable. I'll have to invesstigate. TY.

 

[TNT]

How does this set-up look. It's the new Poly Performance weld in 3-link that can also be a 4-link or a radius arm set-up.

I really like how this system is designed. With some small ramps on the rear mounts to keep from getting hung up as easy it would be perfect.

PolyPerformance XJ 3-link

 

[Jes]

How does this set-up look. It's the new Poly Performance weld in 3-link that can also be a 4-link or a radius arm set-up.

I really like how this system is designed. With some small ramps on the rear mounts to keep from getting hung up as easy it would be perfect.

It is nice but not $1200 nice and the lower link mounts hang... well... low. If you're going to have to do all that work anyway(and have the knoledge to do it) it would be worth it to do all the brackets/links yourself.
Definately a nice Jeepspeed setup though.

 

[TNT]

It is nice but not $1200 nice and the lower link mounts hang... well... low. If you're going to have to do all that work anyway(and have the knoledge to do it) it would be worth it to do all the brackets/links yourself.
Definately a nice Jeepspeed setup though.

It is a great design that can be used for more then JeepSpeed with a few modifications. I posted it to help people visualize a well built 3-link. I'm sure if you have the knowledge to build this kit you could also make from scratch. That way you could fine tune it to you own needs. It is definately well fabracated. It was put on the market because any approved JeepSpeed suspension set-up must be available to the general public. Since it has big price tag on it means their competitors need to pay the price to have it.


Maybe somebody will buy it or learn from it.:shhh:

 

[Ghost]

Also forgot to ask what is the best way to deal with the pinch seam that is spot welded where these links go?