Tj spring rate question

[Scoobienorth]

I’ve got a right hand drive tj on 34’s. Originally I built it on 2.5” rough country coils, I liked the length as I’m set for a fair bit of droop travel and it started as a light weight build . I don’t want to lift it much more but I’ve gained a hard top and some extra gear and time Is doing what it does to the rc coils. I’m spring far too soft now. I don’t want a stiff spring and really would like to stay at 2.5-3” lift. I’m having a hard time finding the spring rate list for tj springs. There used to be stuff posted online all over. I’d like around 170 pound springs up front and 170-180 rear I think. I believe the rc ones are around 155 on the loaded side of the dual rate.

 

[D_JEEPER]

Not sure of the actual spring rate for the TJ but I got into a good tech discussion regarding spring rates with the dudes at Rubicon Express regarding a setup for my CJ. You might send them an email and chat up a bit.

I think what you might also look into is dual rate or triple rate coils. This will give you a decent ride with good droop while maintaining the coil bucket tension so you arent yeeting springs down a mountain side

 

[Scoobienorth]

Not sure of the actual spring rate for the TJ but I got into a good tech discussion regarding spring rates with the dudes at Rubicon Express regarding a setup for my CJ. You might send them an email and chat up a bit.

I think what you might also look into is dual rate or triple rate coils. This will give you a decent ride with good droop while maintaining the coil bucket tension so you arent yeeting springs down a mountain side

The rc coils I have are dual rate, one of the reasons I tried them. The tj getting old is having limited options compared to the good old days. Rock Krawler has a 2” spring but it’s really expensive to get it up to Canada. The 3.5” metal cloak are a bit taller than I want. If I get that high then I need track bars which will have to come from Australia and I’m getting further into this than I want. The rubicon express coils I’ve ran in a tj before and they are incredibly stiff.

 

[D_JEEPER]

The rc coils I have are dual rate, one of the reasons I tried them. The tj getting old is having limited options compared to the good old days. Rock Krawler has a 2” spring but it’s really expensive to get it up to Canada. The 3.5” metal cloak are a bit taller than I want. If I get that high then I need track bars which will have to come from Australia and I’m getting further into this than I want. The rubicon express coils I’ve ran in a tj before and they are incredibly stiff.

So I suppose we should clarify how you are feeling 'stiff' vs 'soft'....solely with regards to your TJ, preferable

Is this the offroad flexing type of feel or the bone jarring pothole hit stiff vs weeble-wobble spongey soft driving characteristics?

One option is to compensate with shocks. You might try finding a stiff shock to swap in to firm up the ride. Back in the day I went the opposite way by buying Billstein 5100s and it made a MASSIVE improvement to soften the ride quality over the hydros I had before that. Another option is to get some adjustable type shocks so you can really dial in the ride. I have some Rancho RS9000s on my CJ, which is running RE 4.5" leaves with a hefty roll cage. On 'normal' setting it is fairly top-heavy and floppy so I crank them up to the most firm setting and that is an immense improvement.... like reconnecting sway bars on the TJ.

Also... just as a note, I would hesitate to baseline ANYTHING off of Rough Country. They are typically a brand for looks over performance. Sure they will give you that lift but you are not to expect a good performance/quality.

 

[Scoobienorth]

So I suppose we should clarify how you are feeling 'stiff' vs 'soft'....solely with regards to your TJ, preferable

Is this the offroad flexing type of feel or the bone jarring pothole hit stiff vs weeble-wobble spongey soft driving characteristics?

One option is to compensate with shocks. You might try finding a stiff shock to swap in to firm up the ride. Back in the day I went the opposite way by buying Billstein 5100s and it made a MASSIVE improvement to soften the ride quality over the hydros I had before that. Another option is to get some adjustable type shocks so you can really dial in the ride. I have some Rancho RS9000s on my CJ, which is running RE 4.5" leaves with a hefty roll cage. On 'normal' setting it is fairly top-heavy and floppy so I crank them up to the most firm setting and that is an immense improvement.... like reconnecting sway bars on the TJ.

Also... just as a note, I would hesitate to baseline ANYTHING off of Rough Country. They are typically a brand for looks over performance. Sure they will give you that lift but you are not to expect a good performance/quality.

I’m really soft at the moment. When putting a light roof rack up to hold snow shovel and traction boards when I stand on the rear bumper the jeep sags right down until the tires touch the fenders. I’m currently running 37’s not the 34’s I’m built for due to deep snow year. But still. 2”+sag is way too much. I’ve been around a while. Knew what I was getting into with the rc coils. With the soft top, half doors, no spare no back seat and new springs It was really good. Between breaking in, adding Currie anti rock and the hardtop and back seat it just went downhill far more than expected

 

[Scoobienorth]

Been looking at jks 3” coils, zone3” as they are easy to get and reasonably priced. Not sure on either though

 

[Tryloff]

You might look at metalcloak springs. They’re long and soft. You’ll need different spring bushings but there’s threads on that.

I have bds for racing on. They’re stiff. Like 210-230. Iron rock told me they were 180-190 range.

 

[crazybluerider]

OME has a 180# front and 160# rear.

They also have fronts at 150# and #140.

 

[D_JEEPER]

Could also consider grabbing a ZJ spring for the front and maybe rear to stiffen things up.

 

[Scoobienorth]

You might look at metalcloak springs. They’re long and soft. You’ll need different spring bushings but there’s threads on that.

I have bds for racing on. They’re stiff. Like 210-230. Iron rock told me they were 180-190 range.

Good info there. I don’t run a spare tire or back bumper so I’m fairly light on my heavy side. I think the bds might be a bit stiff for sure. I didn’t want the metalcloak as it’s 3.5” lift and I’ll need more parts, I’m right hand drive so a track bar would have to come from Australia and I’d need control arms which I didn’t want to do just yet either as I’d like to change a bunch of stuff if I go that far but I’m not ready to budget wise.

 

[Scoobienorth]

Could also consider grabbing a ZJ spring for the front and maybe rear to stiffen things up.

That’s an idea. My front springs are close enough if I had stiffer shocks they would be ok. It’s the rear that’s a real problem. I might still have wj rear coils kicking around. Not sure how they would match up height wise but spring rate is close to what I need. Maybe with a spacer I could hack it together and keep enough flex

 

[Scoobienorth]

OME has a 180# front and 160# rear.

They also have fronts at 150# and #140.

Found the spec sheet I was looking for. They are really short free length. They would be loose at both ends on droop.

 

[Tryloff]

If you like your height, I 100% recommend just getting stiffer shocks.

 

[Scoobienorth]

If you like your height, I 100% recommend just getting stiffer shocks.

My height is ok, and the spring length is perfect but I’m way too soft. If I stand on one back corner of the Jeep with no one in it, it sags right down to my tires.

 

[Tryloff]

For a non race rig, I’ve always been a big fan of the softest springs you can get and tune the rest with shocks or sway bars.

 

[Scoobienorth]

For a non race rig, I’ve always been a big fan of the softest springs you can get and tune the rest with shocks or sway bars.

Ya me too. But I’m too soft. If I stand on one corner, I’m 200 pounds it sinks right down over 2” maybe 3” I’ll mess around with what I have. I might have some stiffer shocks that are close enough to test out and see what it does. My shocks are really soft as well

 

[Tryloff]

I have some really stiff fox 2.0 smooth non resi shocks I could come off of. They’re in a zj with 6” lift. I think they’re 12” travel. I had them tuned and they’re dumb ass stiff now. I need 2.5s now, so they can leave.

 

[Scoobienorth]

Well I decided on bds 2” lift rear coils, after balancing out spring rates, length, availability,price and what’s popular I figured they should work. They are shorter than I’d like and I suspected a touch stiff but my front spring rates are similar (slightly softer) to the bds. After the swap I gained 9/16” height in the rear, it actually drives really well and did what I was after. I need stiffer shocks in the front at a minimum or maybe moving to the bds 3” lift springs. But it’s good enough for now. It’s actually safe to drive again at highway speeds