Spring LENGTH Question

[Dan Carter]

Front springs are 5 inch Landrum 600 lbs. Rears are Eibach 7 inch 750 lbs. On both sets of coil overs to achieve the ride height I want (4.5 inches), I am nearly out of thread on the coil over (hardly any adjustability lefy). While I have done some internet homework, I wasn't absolutely certain about the information.

So, what happens if I retain the lbs (600 and 750) front and back but change the length of the two springs by and inch or more longer?

 

[Mesa]

In the rear you have the option of adjusting the length of the push rod to set ride height. I have (as a reference point) a 6"/600 pound front spring with the lift pad on top and have way more than enough thread to attain the desired ride height. Do you have the front end lift system on your build?

 

[Dan Carter]

Yes, I have the RAMPRO lift kit and it’s on top. I can achieve the height I want, just running out of threads. I see you have a 6x600 up front. If I understand it correctly, the same spring rate (600) regardless of length should yield the same “bounce” if you will. So your 6x600 should perform the same as my 5x600, Correct?

 

[Mesa]

That is correct.
I actually need to recheck my spring length, it may be 4". I'll confirm.

 

[Ken Roberts]

I switched to a 8 inch by 750lb rear spring for just the same reason out back.

If you add the zero rate spring helper in the front you might gain a bit of adjustability back.

 

[Roger Reid]

On the front what happens at full shock extension? Is the spring loose? My reason for asking is could you use a helper or tender spring. These collapse to less than an inch in thickness and keep light spring tension on the spring at full droop to keep things from rattling around. These springs are a zero pound rate and won’t change the original spring rate. Pegasus is one company that sells them.

 

[Dan Carter]

My spring is below the ram, so I never get any separation during full extension. It’s been a long debate amongst builders which way to mount the front strut. IAW QA1 the strut orientation will not impact performance, so simplistically, I oriented the strut to place the ram entry port on the up side to aid in the bleeding process. Running it this way did create a slight problem, but I’m building a replacement upper strut mount that will orient the upper mount rod to be perpendicular to the strut and use the same foot well mounting holes (stock mount has about a 8 degree slant to it). The design will allow me to remove the strut without removing the A arm supports. I’m guessing then, if I went to say a 6x600 spring up front, the spring will perform just like the 5x600 and it will use fewer strut threads to retain the ride height I want.

 

[Frank Clark]

With the Ram on top you can change springs w/o removing the shock (though a different top mount would be welcome!).

I have Ram, 4" (2.25" ID) springs with helpers. Took a small bit of machining to go to 2.25", but it opens up the spring selection.

You can run longer springs in back, I think I ordered 8" last time I changed them, run whatever length gets you in the adjustment range you want. But do make sure your linkage rods are adjusted first.