XR observations

[Jtphoto]

Those are similarly equipped jlurxr in a 2.0t and a 392. Again the rear weight would be very similar. if @At Risk Ute can in and said that he had a full overland set up in his 2.0t and an 1/8 of a tank of gas in the 392 sure an inch isn’t bad. But I don’t think that is the case.

Correct. The rear springs make little to no difference what motor you have other then the 4Xe. If the 2.0 had plastic bumpers and the 392 had factory steel the front would be opposite ends of the spectrum.

Sponsored

 

[AnnDee4444]

The rear springs make little to no difference what motor you have other then the 4Xe. If the 2.0 had plastic bumpers and the 392 had factory steel the front would be opposite ends of the spectrum.

Where is this information coming from?

 

[Jtphoto]

Where is this information coming from?

A few things I came across from site to site. There’s a bit of info on the Rock Krawler site .. The rear springs are different on the diesel with a heavier spring rate according to RK but I have varying accounts. The 392 however has a different flush mount rear spring perch and requires a different spring for that but doesn’t specify the spring rate being any heavier.

 

[At Risk Ute]

Those are similarly equipped jlurxr in a 2.0t and a 392. Again the rear weight would be very similar. if @At Risk Ute can in and said that he had a full overland set up in his 2.0t and an 1/8 of a tank of gas in the 392 sure an inch isn’t bad. But I don’t think that is the case.

Correct. My measurements were more scientific than I thought. Both Jeeps had full tanks of gas, no cargo, and stock steel rear bumpers. 2.0 XR has a hard top while the 392 XR has a SOT (lighter top I’m guessing).

Reckon the 392 XR has stiffer springs. ??‍

 

[At Risk Ute]

Looking good! I am also contemplating if I should do this.

Can you please let us know your driving impressions? Does it feel more planted in the corners? what about the nose dive feeling while braking? Did you change LCAs on this to Mopar lift ones or the trackbars?

Thanks!

Definitely turns quicker and feels more planted hitting bumps / less wobble.

LCAs are still stock but I wouldn’t mind swapping those out next.

 

[Booker]

Question for y’all, i bought rubi xr springs from a steel bumper xr. How much rake can I expect when I install a winch? I’m debating installing it with a 3/4” spacer or a 1/2” spacer.

I put in a 3/4” spacer on the front after the winch and it leveled everything out perfectly. I have the steel bumper too.

 

[Wabujitsu]

A JKS lift with HD dual-rate springs (2.5” JKS lift) leveled mine out perfectly, in spite of the aftermarket weight. Not an XR, but it does have 35s and an aftermarket Tyger tailgate reinforcement/spare relocation kit on the back.

 

[aldo98229]

“XR” is now so last year...

?

 

[LCW]

The diesel and 392 weigh somewhere in the neighborhood of 400-500lbs more than the other engine options so they have much stiffer springs. Same thing happens when you put loaded 4dr springs on 2dr. You only get lift because of a much stiffer spring. But the ride will suffer.
I actually had this discussion with Mike at RK. I have a heavy winch/bumper combo 215lbs that dropped my RK springs more then I like. My idea was to use RK diesel springs which have a higher spring rate. He suggested it would then sit too high and ride rough.

I’m running 392 non-XR springs and 392 Fox shocks on my JLUR with 35s (ie same 315/70R17 tire as XR) with mopar steel front and Warn EVO 10S winch and it rides and sits perfectly.

 

[CptFloridaMan]

Ok so I’m gonna install my xr springs this month, im still debating with spacers. I’m leaning towards 3/4” now seeing that I already have steel bumpers and a 35 mounted in the rear.

How much rake does a factory steel bumper, hardtop rubi xr have?

 

[Jtphoto]

I would rather have a bit longer spring to compress to gain that 3/4” and have the extra free spring so it doesn’t pop out then put in a 3/4” spacer.

 

[Capt. Don]

Actually smaller per the spec sheet.

13.6 x .86 (345 x 22) vented rotor — Sahara 4xe, Xtreme Recon Pkg
14 x .86 (350 x 22) vented rotor — Rubicon 4xe, Rubicon 392

I disagree. My research on what XR “Performance Brakes” means larger and thicker rear rotors and larger rear brake pistons over stock Rubicon. No change to front brakes.

 

[Capt. Don]

I wonder, if the XR is ordered with the steel bumpers are the springs changed for the additional weight over the front?

Yes, my plastic bumpers on my JLUHT show 5900# springs on the build sheet. A friend’s JLURXR with steel bumpers shows 6100# springs on his build sheet. Other heavy options are driving this also.

 

[Capt. Don]

Is it confirmed that there is a difference in the springs that come from the factory if you order the steel bumper group on the XR? And if so, is it confirmed that there is a difference in the spacing on the bump stop with such springs? I would go out to the garage and measure, but I'm waiting on Jeep to build my XR with the steel bumper group ...

Your build sheet will tell you which springs. My JLUHT with XR has 5900# springs. A friend’s JLURXR with steel bumpers has 6100# springs.
Another observation, at 37 psi cold in the tires, after 4,000 miles I was thinking I needed a new lift. Stiff sidewalls meant rapid initial compression and seemed to overload compression damping of the front shocks. Light steering and poor feel. I dropped to 30psi cold to allow the 35s to work properly and it is like a different Jeep. Steers better, better traction, better ride and the 35s are now doing their part in initial compression. Why have the big sidewalls of the 35s and not use them? I don’t notice the bump stops now. Simple change. Big impact on the stock XR suspension. Easier on the suspension and definitely on the shocks, easier on your tires. Try it for a week. I still see 24 mpg at 60 mph over 100 miles loop with eTorque V-6, 850re trans and 4.56 gears. That is great. Push to 75 and watch that drop by 25%(!)(aerodynamics of a brick). I have not been able to measure a difference with 30psi versus 37 psi in mpg at 60 mph.

 

[GATORB8]

I disagree. My research on what XR “Performance Brakes” means larger and thicker rear rotors and larger rear brake pistons over stock Rubicon. No change to front brakes.

That’s from the Jeep spec sheet.

Sponsored