Shock measurement

[J C]

I am planning on putting the lift spindles with a torsion twist in the front with the superlift 4" lift springs in the rear. I would also like to replace all the shocks with some Rancho RSX. I placed an order on Sam's Offroad website and recently got an email saying that they did not carry a shock for my application!? I included in my vehicle description a 4" lift, was this the problem, because i know RSX's can be put on the trac. I then called another off road shop for some shocks and they said they could not sell me extended lenght shock until i had my lift done and measured the distance from the mount points, and then they might have to order them! Has anyone done a similar lift and measured this out? I am trying to do this lift in a specific time window and would like to get everything done at one time. Any other reccommendations? thanks.

 

[Yardsale]

Edit (not sure when I cut this) -> The spindle and torsion twist do not change the amount of front suspension travel (it only changes the resting position), so stock length will work.



A four inch spring lift in the rear does change the amount of suspension travel. You will be best served doing exactly what you propose - getting the information from soemone who has done this or waiting until the springs are installed.



Maybe contact Superlift. They must sell a full kit including shocks and you could get the model of the shock that comes in the kit and lookup the travel specification for that.



Very rough:



At rest, the shock will have to be four inches longer than stock.

Figure at full compression, the shock has to retract to the same length as the stock shock (unless the bump stops are being changed).

At full droop there is about four to six inches more extension.



So, stock retraction length and about four to six inches longer at extension. Again, very rough. this is why you need to check.

 

[Richard L]

In an ideal world, the shock should be expanded to the middle of it's travel when the vehicle is at it's normal ride height. This allows the shock to expand and compress equally for the full suspension travel.



When you alter the suspension lift or lower you are moving the pistion up or down in the shock because of the change in ride height. The other problem is that when you lift or lower your vehicle the new suspension geometry may limit the upward or downward travel of the suspension where it is not equally up and down from the ride height position. for example, you may only have 2" of compression, but 6 inches of expansion.



You may also need to know your spring rates, and full suspension travel to get the right shocks.



...Rich

 

[Mat Deegan]

i have about 8" of lift on mine; 3" body, 5" suspension. i think Richard is right. however, im still using stock length with no problems. you'll be fine with just stock length.

 

[Yardsale]

Not necessarily. Check.