Let's talk optimal build for 31" tires

Start with really big bumpers and tire carrier and eventually switch to really small bumpers and put the tire back on the tub.
Remove bumpers, fenders, SwayLoc, go to a 15 gallon tank and call it Jenny Craig! šŸ˜‰
 
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Start with really big bumpers and tire carrier and eventually switch to really small bumpers and put the tire back on the tub.
I wish I would've considered weight when buying my rear bumper. the whole thing is well over 100 lbs :eek:... one of these days I'll go with an Exogate and UCF rear though.
 
I wish I would've considered weight when buying my rear bumper. the whole thing is well over 100 lbs :eek:... one of these days I'll go with an Exogate and UCF rear though.
Spare delete saves 80lbs for a 33. Get a couple valve stems, the stem install tool, plugs, call it Richard Simmons.

1611977421312.webp
 
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If you look back at the first 5-6 years of my build and all I told you was that I had steel bumpers, you would wonder why I wasn't getting as much lift out of those springs as most usually do. I still have steel bumpers, but the Jeep is now 300lbs lighter in those areas than it used to be.

As a thought exercise for everyone, let's add that 300lb weight to the center of a Jeep with 140lb/in springs on all four corners. How much does the ride height change?
About a half inch on all four corners. What point are you driving at?

@JMT has a factory bumper and steel cable. I was simply comparing to the rather large steel bumper I have, but a synthetic cable and noting I was getting a half inch more lift it from the same springs. Now that he updated his lift amount, my OCD is satisfied.
 
About a half inch on all four corners. What point are you driving at?

...

It's just a way to get people to understand how springs work and why results may vary. Nothing more.
 
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Heck, even not considering aftermarket additions, weight could vary a lot in stock form. Let's say you have one jeep that has a hardtop, back seat, full doors, 6 cylinder engine, and spare, and another jeep with a soft top, back seat removed, half doors, 4 cylinder engine, and spare removed. That's a lot of weight difference. Not to mention cargo or passengers. There's a lot in play, and even the smaller things add up.
 
I pulled out the 3" Nth Degree springs I have and measured those. As a comparison, here are the numbers, as compared to the OME springs I'm considering.

OME 2933 = 19.48
Nth SFTJ+30A = 20.75

OME 2941 = 15.35
Nth SRTJ+30B = 14.5

I don't know if it matters or not, but the Nth springs are progressive, while the OME are Linear
qYx1HAl.jpg


Also, as a reference, in this picture my previous TJ was sitting on H&R 1" springs, a 1" BL, and 31" tires. There was a noticeable rake. It definitely could have used a 3/4" or 1" spacer up front.
XCoNrxh.jpg



In the pictures below, it's sitting on the 3" Nth springs, a 1" BL, and 31" tires. The one thing I like about the Nth springs is there was no need for a spacer in the front. There was a slight rake, but it was barely noticeable.
xjlwxSA.jpg


pPcau9N.jpg
 
I pulled out the 3" Nth Degree springs I have and measured those. As a comparison, here are the numbers, as compared to the OME springs I'm considering.

OME 2933 = 19.48
Nth SFTJ+30A = 20.75

OME 2941 = 15.35
Nth SRTJ+30B = 14.5

I don't know if it matters or not, but the Nth springs are progressive, while the OME are Linear
View attachment 222373

Also, as a reference, in this picture my previous TJ was sitting on H&R 1" springs, a 1" BL, and 31" tires. There was a noticeable rake. It definitely could have used a 3/4" or 1" spacer up front.
View attachment 222374


In the pictures below, it's sitting on the 3" Nth springs, a 1" BL, and 31" tires. The one thing I like about the Nth springs is there was no need for a spacer in the front. There was a slight rake, but it was barely noticeable.
View attachment 222375

View attachment 222376
I like the look of the H&R build and 31’s better than the Nth. It seems like the Nth gives too much lift for 31’s. I’d try the OME 2933 and 2941 and see where you end up.
 
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At this point it loos like the OME springs will provide slightly less ride height than the Nth springs I already have. Given that, it's looking like H&R would be the best bang for the buck. Based on that, two questions:

Question #1 - Does anyone know of a 1" spacer for the front? I'm only seeing 1" and 1.5".

Question #2 - Which Rancho shocks would be the best match with a 1" spring and 1" spacer. There's a version for 0" - 2" lift
https://www.amazon.com/gp/product/B013PUD120/?tag=wranglerorg-20

And a version that's for 1" lift
https://www.amazon.com/dp/B01963XI50/?tag=wranglerorg-20
 
At this point it loos like the OME springs will provide slightly less ride height than the Nth springs I already have. Given that, it's looking like H&R would be the best bang for the buck. Based on that, two questions:

Question #1 - Does anyone know of a 1" spacer for the front? I'm only seeing 1" and 1.5".

Question #2 - Which Rancho shocks would be the best match with a 1" spring and 1" spacer. There's a version for 0" - 2" lift
https://www.amazon.com/gp/product/B013PUD120/?tag=wranglerorg-20

And a version that's for 1" lift
https://www.amazon.com/dp/B01963XI50/?tag=wranglerorg-20
Teraflex makes a 1.25ā€ spacer. I used 55124 and 55128 for Rancho springs with my combo.
 
As the OP, I wanted to close the loop on this thread. What did I get out of it? The knowledge that an "optimal" build for 31" tires isn't really different than one for 33" tires. The most important factor for doing any build is a realistic assessment of how you'll use the Jeep and what you're willing to spend. For example, if your budget is low and you plan on driving fire roads, a simple budget boost and 31" tires will do the trick. If however you plan to conquer rocks on 31" tires, an optimal build would include improvements to belly height, spring and shock travel, armor, gearing/lockers, a winch, and a willingness/ability to spend more money and time. Some may call the later "overkill", while others would not.

FWIW, the thread helped shape the direction of the latest build, as I seek my own 31" tire sweet spot. Thanks to all who took the time to provide comments and input. Lastly, that direction, at least from the spring choice perspective, can be seen in the link below, i.e. Post #151.

https://wranglertjforum.com/threads/a-lesson-learned—keep-it-light-and-nimble.44924/post-792816
 
thoughts on cromo’s for 31’s?
Not needed for 31" tires. However, for my build, they are going in front and rear. This is not your standard 31" tire build. You know that though!
 
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Ah, um, ok...... :rolleyes:

(That was for Vasq)
If you want them you should get them, but I don't see 31s needing chromoly axles.
And you asked for thoughts, though i suppose my response was too short? I just can't imagine a situation with 31s that would break a stock shaft, without breaking a whole bunch of other things (like jumping the jeep or something silly).
 
If you want them you should get them, but I don't see 31s needing chromoly axles.
And you asked for thoughts, though i suppose my response was too short? I just can't imagine a situation with 31s that would break a stock shaft, without breaking a whole bunch of other things (like jumping the jeep or something silly).
The clay in the SE will break things most people shake their heads over. It’s stupid simple to get bound up and blow out a front. So yeah in the SE, I’m all about it. I asked to see what opinions in other areas were. Obviously you think it’s a worthless upgrade without ā€œprovingā€ failure.