4-link design & tuning: 2wd trucks

Hurley

Hurley

BLAKLUNG
Can we get a discussion going about 4-link design?

In 2008 I back-halfed my truck with DOM tube and put together a 4-link setup with 6" travel coilovers. I will admit my design was a "first timer's" attempt using the 4-link calculator found on some of the 4x4 forums. It has proven worthy on the street, but I am curious as to it's performance when i throw a pair of slicks on it and get some power going to them.

I have included the info I *estimated* for my original calculation for roll center, anti-squat, etc.


The calculated results:
97% anti-squat
19" Roll-center height
8deg roll axis angle (oversteer)
 

Attachments

  • 4-link 4-21-10.jpg
    4-link 4-21-10.jpg
    70.6 KB · Views: 124
I have nothing to contribute, but I am hoping this discussion goes some where, I'd like to 4-link my dually in the future.
 
I will add this, my original design intent was to obtain 100% AS, but now I am wondering if that value is too high.

I have considered experimenting with lowering the axle end of the upper links 2" (i.e. drill through the link brackets and re-bolt), probably going to try that. the link calculator says anti-squat will decrease to ~75%, and the roll center increase to 20"
 
Uppers converge on the frame side, lowers are parallel to each other. The diagram shows the suspension at the intended ride height.
 
OK
its simple to do it , and it takes a life time of racing to understand it

you need scales first.
 
SMOKIN93 said:
Scales or worthless, unless you run some dumb comp car or bracket lapper but probly still not needed.
Click to expand...

I hope your kindin'. Drag Racing is'nt ALL about tring to get a over weight 4x4 truck down track. Scales is one of the more important tools in a racers shop, if he has any clue what the hell's going on to begin with. Ryan
 
Once you corner scale it, I think your estimate for CG height will change to 25-26" but there's no way to know until you scale it.
 
they allow you to balance you vehicle on all 4 tires via the adjustable 4 link. you weight jack the vehicle to find a balance that works for the car. every car is different. that's why those weld in 4 link kits have 20 holes in the brackets. so you can adjust every aspect of the rear end, to make it hook better on launch, to make it drive straight on the track, to lift the front, to plant the back. there is a lot to it... and to be honest i haven't even played with one yet.
 
We have an awesome alignment shop around here local that can set one up perfectly everytime, I imagine you could find one locally there as well.
 
Just set the record over the weekend for the fastest converter driven pro mod, 6.04 242, never been on a set of scales.
 
I would like to know more about this too. I have tried to set up my truck's 4 link and realy don't know all the tricks. I have tried to find some scales to see what the wieghts are but no luck.

How about a step by step how too for us...
 
No not at all. I did not mean for that to sound like sarcasm. What is the first step to setting up a 2wd chassis?

Thanks
 
You must log in or register to reply here.
Back
Top