Front coil springs... Looking for something softer

[anthrax323]

My 2001 XJ is sitting at around 5.25" of lift right now, thanks to Rubicon Express RE1300 (3.5") coils and the JKS ACOS setup. I just replaced my 5100's up front with the 6" lift models (11.5" travel, woot), and have reached the point that I'd really like to soften the ride a bit.

Front bumper is a Rigidco FbG (no winch), so I don't have a whole lot of weight up there.

I found the following Jeep Forum thread about various spring options:

http://www.jeepforum.com/forum/f11/springs-heights-their-spring-rates-613756/

Mine have a spring rate of 240 lbs/in, which is proving to be far too much for my liking.

Has anyone run both the RE 3.5" and 4.5" coils that could comment on the lift they actually provide? The 4.5" have a rate of 164 lbs/in, which would be far closer to stock (147 lbs/in from what I'm seeing), but I'm concerned that they're longer overall and would yield unwanted lift.

My ACOS setup is currently at its lowest possible setting, and was installed because of this eventuality, so I have plenty of room to adjust if they're for less lift.

Thoughts?

 

[stockerwithalocker]

I cannot comment on the height difference as I never measured, but I do know the 4.5" coils were much softer than the 3.5" coils. I wanted the opposite, the 4.5" was too soft and the 3.5" coils were much stiffer.

 

[anthrax323]

Do you recall any height difference whatsoever with the stiffer 3.5's? The 4.5's are cheap enough that I'm almost willing to take the chance.

I'm looking for something the same height or lower.

 

[mtbxj87]

pac jeep speed springs? Jegs sells them

 

[Johnnie Walker]

This. Pac sells lift springs in different spring rates

 

[anthrax323]

Damn, kinda pricey but they seem to be bar-none the ideal coil option for Jeepspeed (other than Deaver, who only makes 4" coils for XJs now).

I could live without the neon orange, but it's not a big deal.

Anyone have any experience with what the 4" lift springs actually yield?

 

[Johnnie Walker]

Check out the Team Naxja 4643 build thread, and/or contact Cal. That is what they run on that heep.

 

[NJXJ666]

Synergy?

 

[MJ3000]

I ran the RE 3.5's for 3 or so years and they rode noticably stiff to me. I swapped out for the 4.5's 2 years ago and they ride much nicer, I like them. Plush on bumps and no real lean or roll in corners. I must note that I also upgraded to 5100's when I did the 4.5's so there's that too. As far as height goes, I believe (it's been a while) my 3.5's measured 4-4.25" of lift and the 4.5's put me right at 5". As cheap as the 4.5's are I'd just try them honestly.

 

[PhotoJared]

With that much lift long arms will help more than springs...

 

[GordoSmasho]

With that much lift long arms will help more than springs...

X2

I run the re3.5" coils up front and they are much stiffer than the stock coils. However i run drop brackets and re adjustable arms and that puts all the arm geometry back to stock angles. It rides like a caddy. But very stable.

The stiffer springs up front also make the rear leaves work harder when flexing. If you run really soft springs up front your front end will be doing all the flexing. Path of least resistance and all. I found with stiffer front end the vehicle as a whole is much more balanced on and offroad. Control arm angle and shock choice plays way more of a role in a comfortable road ride than the stiffness of the coil IMO. I have also run the re 4.5" with the same setup. I prefer the hight spring rate over the extra inch.

 

[anthrax323]

Absolutely. I'm running RE drop brackets up front with Bilstein 5100s (6") and JKS 6100/7100 control arms (Clevite bushings), and RE1463 leaves (190 lbs/in) with JKS boomerang shackles out back. My shackle angle is damn near perfect - almost exactly 90° eye-to-eye from the spring's datum line.

The front coils are literally just too stiff (even for my shocks). I have no winch up front, nor armor, so the thing tends to skitter across washboards. I really want something more supple.

 

[ROBZ95Xj]

i hated the RE 4.5's I had granted I have a exo and winch, there a very soft coil, maybe to soft look into a coil that's more in the 190 in/lb range. I wish I never got rid of my RK 4.5's

 

[PhotoJared]

i hated the RE 4.5's I had granted I have a exo and winch, there a very soft coil, maybe to soft look into a coil that's more in the 190 in/lb range. I wish I never got rid of my RK 4.5's

I had RE 3.5", 4.5" and now 5.5". I didnt even drive on the 4.5" because i lost lift compared to the 3.5". I agree, with armor, bumper, winch they're just too soft.

 

[PhotoJared]

Absolutely. I'm running RE drop brackets up front with Bilstein 5100s (6") and JKS 6100/7100 control arms (Clevite bushings), and RE1463 leaves (190 lbs/in) with JKS boomerang shackles out back. My shackle angle is damn near perfect - almost exactly 90° eye-to-eye from the spring's datum line.

The front coils are literally just too stiff (even for my shocks). I have no winch up front, nor armor, so the thing tends to skitter across washboards. I really want something more supple.

I may be miss-interpreting this, but you dont want a 90 degree shackle angle.

 

[GordoSmasho]

Should be at 45* at ride height. It will ride like a dumptruck at 90*

 

[anthrax323]

I've always understood that the shackle should be perpendicular to the datum line at ride height:

http://www.quadratec.com/Assets/Knowledgebase/Image/clip_image001.gif

Seems like a 45° would make it much stiffer, as it'd limit the spring's ability to flatten?

 

[PhotoJared]

This is about how it should look.

 

[anthrax323]

Looks like you're sitting at about a 70-75° angle relative to the datum line.

So when people say 45°, they mean to the chassis?

 

[PhotoJared]

Looks like you're sitting at about a 70-75° angle relative to the datum line.

So when people say 45°, they mean to the chassis?

Yes.