JK Evo coilovers question

zonearc

New member
My wife has a 2dr on evo long arms with their coilovers. As I'm sure you're aware, their rear coilovers are "custom" length for their kit. She's had them for years and it's always had an issue with the rear and I'm finally circling around to it because the local shop that put them on hasn't been helpful and I'm finally in a position to work on this.

So, when she drives through a rut or dip in the road, the rear suspension bottoms out and you get an audible clunk. The issue is that there's only ~2" if shaft showing on the rear coilovers (pictures attached). I originally played with this a bit by adding air bumps and playing with height and pressure, but ... I mean ... you can't really *fix* the problem with only 2" of uptravel as that's just short enough that you CAN bottom it out, or make the bumps stop hard that THEY hit so hard to prevent you from bottoming out the coilover. Either way, it sucks from a ride perspective.

I'm wondering though ... is this the way that kit is designed or is it possible something got messed up (wrong length shocks, wrong lower/upper shock mounts altering the height, etc)? Or, was this really designed with such a low shock travel?

Now, my next thing was going to compress the spring more. 1" adjustment usually equals about 1/2" height right? There's not much more we can go, but maybe I can raise up her rear by 1" and get us to 3-3.5" shock travel. But, it'll add a ton more spring rate/stiffness so that's either good or bad too depending on how it feels.

Any input/guidance appreciated. Thank you!

20240123_115557.jpg 20240123_115552.jpg 20240123_115600.jpg
 

wayoflife

Administrator
Staff member
First off, you've got a lot of preload on your coilover. Second, it looks like you're riding on your timing rings and that means, you're ONLY riding on your secondary springs. Running heavier spring rates top and bottom will help mitigate your problem. And, with heavier spring rates, you can run your Jeep taller and that will give you more shock travel. That should help solve your bottoming out issue and make your ride better.
 

zonearc

New member
Yeah. She's 200/250. That's not much now that I think about it. Thank you so much. Any guidance on where to calculate or any ballpark suggestions on a 2 DR JK on 37s with tons, and all the usual armor including sport cage? Usual guidance is 50lb difference between upper and lower so I wonder if we should try a set of 300/350.
 

wayoflife

Administrator
Staff member
Yeah. She's 200/250. That's not much now that I think about it. Thank you so much. Any guidance on where to calculate or any ballpark suggestions on a 2 DR JK on 37s with tons, and all the usual armor including sport cage? Usual guidance is 50lb difference between upper and lower so I wonder if we should try a set of 300/350.
It really isn't necessary to run a 50lb difference. You can totally run 250/250 as your overall ride is still divided between the two. Typically, the secondary spring is heavier just to help absorb bigger hits. That said and looking at your setup, I might have recommended 250/300 but with as much weight as you have on your Jeep, that may only give you about an inch more of lift. And really, 3" total up travel isn't bad but you may still have to run about the same amount of preload to get you there. My only reluctance to going 300/350 is that your overall ride might get compromised. Sure, it'll get you sitting taller and eliminate the need for so much preload but your overall ride may feel harsh.

If it were me, I would buy a set of Eibach springs as they are cheaper and get them in 250/300 and if it's still not enough, bump up from there. And believe me, I have a bunch of coils on a shelf just because I've done this a lot. One other thing, I see you're setup with what looks like 10" over 12" coils. It would be harder to install but you could run 12" over 12" in the 250/300 and that would help as well.
 

Seahawkfan

Hooked
If it were me, I would buy a set of Eibach springs as they are cheaper and get them in 250/300 and if it's still not enough, bump up from there. And believe me, I have a bunch of coils on a shelf just because I've done this a lot. One other thing, I see you're setup with what looks like 10" over 12" coils. It would be harder to install but you could run 12" over 12" in the 250/300 and that would help as well.
So glad this topic came up!
I have recently been looking for some better solutions to my set-up. And this is what was also recommended. (y)
 
Top Bottom