XJ vs. ZJ coil spring rate confusion

[nrwphoto]

So far I have found the posted XJ spring rate as 142# and ZJ as 190# (with a few differences). And the OME 160# and 180# depending on the spring. What I am wondering is what stock springs are these ratings from? I have an XJ UpCountry, is their a difference for my spring rate or is it length? And what is the ZJ rating from, I-6, V8, UpCountry? If you know the different rates for each of these it would be much appreciated. Like the idea of a budget spring swap and would like to know what to expect with each. Thanks

 

[Tim_MN]

XJ (and ZJ) Up Country springs are +1" taller than stock springs and have a higher spring rate. Lift springs achieve their lift by either being physically longer, using a higher spring rate, or a combination of both. You can always use a coil spring spacer.

ZJ's have a number of different stock coils with different spring rates for I-6 and V-8. ZJ Up Country (+1") could have been I-6 or V-8 so it is logical to assume that there might be 2 ZJ UpCountry coils.

 

[Johnnie Walker]

Since you alread have an extra inch. ZJ coils themselves will not net that much more. How much lift are you wanting? A lot of guys go with the OME 934? I believe.
Or if you can get cheap or free ZJ V8 upcountry coils, maybe add in a spacer also or a couple of stock coil isolators.

 

[nrwphoto]

I am only looking for 2" of lift, just want to keep the 30"s from rubbing and keep a low center of gravity. I would like an OME setup, but I can't afford it right now. Already spending a couple grand on parts for new cooling system and swapping in 4.10 front and rear with Detroit TT in the rear. I have access to free springs from an old ZJ V8 that was in a minor accident and parked about 8 yrs ago. Just trying to figure out if it's worth it, not sure what the spring rates are for them, or if I just need to source UpCountry springs if I choose to swap. I would like to stay away from large spacers. Also planning a hybrid pack in the rear to level things out.

 

[1990heepxj]

add 2 more stock coil isolaters per side, that will give a little over an inch more lift

 

[Tim_MN]

I am only looking for 2" of lift.....

ZJ coils are a crap shoot, you don't know the exact XJ lift amount until you install them.

Coil spring spacers are commonly used and they cause no problems. I have had 2" spacers installed for a few years. They worked fine in Moab on Hell's Revenge.

 

[yossarian19]

XJ spring = stock
XJ Upcountry = +1
ZJ V8 = ~1.5"
ZJ UpCountry V8 = +2"
ZJ I6 = ~1/2"
ZJ I6 UpCountry ~1"

Your mileage may vary but that is what I'd expect.

 

[nrwphoto]

Alright well let me look at it from a different angle. Which setup or springs would give me the most flex (assuming sway bar discos are used), a ZJ spring or stick with what I have and 1.5-2" spacers?

 

[98stocker]

The difference will be negligible. Go with whatever you have. I would get the zj's and a couple more isolators to get whatever lift you want. I like stiffer springs whenever possible cause speed is fun, and bumps hurt when you bottom out.

 

[badron]

30"s from rubbing and keep a low center of gravity.
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you are rubbing with 30s?
Well lift will generaly not stop rubbing all together. Not unless you mod binds and stops upward flex. It will give you a little more flex before rubbing starts. ON STOCK RIMS.
Stops will fix the rubbing problem. Add a puck to the front should be all you need with 30"