More 4 link questions.

[LT.]

I had this in the other 4 link question thread but no one answered any of my questions. I am needing some answers if y'all would not mind. Any help would be fantastic as I am now thinking about pouring gas on the rig and lighting a match.

Is there a problem to making the upper links less than 40*? I was really wanting to run my lowers out to about 55" but, if I make my uppers at 38.5" ( 70% of the lowers) they will not be at 40*. Also, is there an idiot proof way to tell if my measurements will work or not? The reason I had wanted 55" lowers is that would put my lower links about where the arc of the rear driveshaft is. I read that the separation of the links on the frame of the vehicle should be 50% of the distance on the axle is this correct? I will end up with about 10" of separation on the housing and I was planing on 5" in the center of the rig. Do I need more at the frame? What about when I do the front? My lowers were going to be triangulated and the uppers were going to be straight with the frame rails. What should the % be from the lowers? Do I need a track bar in the front with the triangulated lowers?

Thanks for all the help.

LT.

 

[ChestonScout]

Numbers mean nothing to me....lol



As long as you have 40 degrees seperation on your triangulated lowers, you will not need a track bar for your front 4 link. That is exactly how mine is set up.


Is the rear going to be dual triangulated?

If it is, you do not need to be at 40 degrees. You need to have a total of 40 between the top and the bottom so if your lowers are say 30 and your uppers are 30 you will have 60 total which will be way over 40. So if your lowers are 40 and the uppers are 20 it will be perfect!

I think you are reading into this WAY to much. I know you want it to work perfectly but you can crunch numbers for the next 5 years and it still wont be perfect. You just have to kind of suck it up and get it done.

 

[LT.]

Thanks Cheston. Yeah, the rear is a dual triangulated 4 link. Here are some of the numbers that I have pulled.
Wheelbase is 112.625".
Tires measure out to be 41.25" loaded.
Link separation needs to be 10.3125" I currently have 8.25". The lowers will be located lower than the center line of the rear axle. What about the separation at the frame? Is 50% still the norm? I am thinking about 75% to get away from any anti squat. Or about 7.5"
Inside of frame to inside of frame is 33.5" at the rear.
Inside of frame to inside of frame is 25.5625
Lower links I wanted to be 55" Is this too long for my wheelbase?
Uppers would be 38.5" at 70%. Should this be more than 70%?
Top of tranny is 45.25" for center of gravity.
Frame rails are 2" X 6".

Does any of this make any sense to y'all? Any help y'all can give would be fantastic. I almost forgot, all of this will be working in conjunction with 16" travel FOA coil-over shocks.

LT.

 

[RockMonkey]

You don't have to have the uppers 70% of the lowers. You can make them the same length, longer, or shorter, and they'll work just fine. I would NOT do 50% of the seperation at the frame that you have at the axle. If you do that, make an adjustable bracket with multiple holes, and put the top hole at 100% (or close to it) the seperation at the axle.

 

[LT.]

That is what I was gathering from the last thread. Is 75% a better way to go? What would the difference between shorter or longer uppers be?

LT.

 

[RockMonkey]

That is what I was gathering from the last thread. Is 75% a better way to go? What would the difference between shorter or longer uppers be?

LT.

The justification I've seen for shorter arms is that as the suspension droops, the shorter upper arms will reduce the antisquat over a suspension with equal-length arms. The problem I see is that the increased angle of the arms relative to the ground is going to be a much tharger factor to determine anti-squat, so this argument basically doesn't work.

More later, gotta go for now.

 

[LT.]

Thanks fellas for all the answers. I really can't tell you how much it means to me. I simply cannot afford to do this project more than once. What about my measurements at the axle for VS? I figured that I would need 10.3125" but if I do that then my lower links would be near the bottom of the rear axle. Would I be okay if I went to the center of the rear axle and only had a VS of 8.25"?

LT.

 

[Goose]

Thanks Cheston. Yeah, the rear is a dual triangulated 4 link. Here are some of the numbers that I have pulled.
Wheelbase is 112.625".
Tires measure out to be 41.25" loaded.
Link separation needs to be 10.3125" I currently have 8.25". The lowers will be located lower than the center line of the rear axle. What about the separation at the frame? Is 50% still the norm? I am thinking about 75% to get away from any anti squat. Or about 7.5"
Inside of frame to inside of frame is 33.5" at the rear.
Inside of frame to inside of frame is 25.5625
Lower links I wanted to be 55" Is this too long for my wheelbase?
Uppers would be 38.5" at 70%. Should this be more than 70%?
Top of tranny is 45.25" for center of gravity.
Frame rails are 2" X 6".

Does any of this make any sense to y'all? Any help y'all can give would be fantastic. I almost forgot, all of this will be working in conjunction with 16" travel FOA coil-over shocks.

LT.

Im in the process of linking my rear. My wheel base is 122" My lower links will be 53 ish. It seems that with links everything has a give & take to it.

 

[LT.]

Im in the process of linking my rear. My wheel base is 122" My lower links will be 53 ish. It seems that with links everything has a give & take to it.

Yeah, I am finding that out the hard way. I went into this project with the frame of mind that the suspension was going to take priority over everything else. If the gas tank was in the way I would just move it. Exhaust same thing. But, if you are at 122" WB and your lowers are going to be 53"ish then I may be way off base with wanting 55" lowers. Anyone else?

LT.

 

[RockMonkey]

Yeah, I am finding that out the hard way. I went into this project with the frame of mind that the suspension was going to take priority over everything else. If the gas tank was in the way I would just move it. Exhaust same thing. But, if you are at 122" WB and your lowers are going to be 53"ish then I may be way off base with wanting 55" lowers. Anyone else?

LT.

55" lower control arms are really (really) long. Really. Mine are about 45" and that's still quite long. That's not necessarily bad. In fact, it could help you get the geometry you want, but it is not a usual length. The longer you make your lower links the stronger you need to make them, since a rock conveniently placed in the middle will have more leverage to bend the arm.

 

[Goose]

Yeah, I am finding that out the hard way. I went into this project with the frame of mind that the suspension was going to take priority over everything else. If the gas tank was in the way I would just move it. Exhaust same thing. But, if you are at 122" WB and your lowers are going to be 53"ish then I may be way off base with wanting 55" lowers. Anyone else?

LT.

rockmonkey is right on, on 112 W/b 55" seems long. (your t-case must be closer to the front than mine.) longer bottom links can give you a flatter angle, but like rockmonkey said,the longer you go they stronger they need to be.
In my case (53"lowers) Im going with a minimum of 2" 7/16 wall dom.

 

[LT.]

These are all things that I really need, thanks fellas. 55" was chosen to keep the lowers at around 7* and it also lined up with the rear output on the driveshaft. I was thinking that this would allow me to keep my current driveshaft that is not a long travel unit. I don't really know what I am going to do. The idea of taking it somewhere is more and more appealing all the time.

LT.