Doctor Bone Smash
TJ Enthusiast
I’ve been looking at some Cherokee rims in 16x7. Liberty rims would do the trick also.
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Let's talk optimal build for 31" tires
- Thread starter Irun
- Start date
I had a lot of fun for years on 31s. But also a lot of frustration.
My advice is to focus on lifting everything you can because you're going to need everything you can get (belly, bumpers, body mounts, linkages, etc). Also keep it as light as possible so that when you do get hung up you can hopefully push your way over it. While ZJ steering upgrade is plenty for the street and light trails, upgrading to the Currie steering may be worth looking into since you're going to be bashing it a lot.
My advice is to focus on lifting everything you can because you're going to need everything you can get (belly, bumpers, body mounts, linkages, etc). Also keep it as light as possible so that when you do get hung up you can hopefully push your way over it. While ZJ steering upgrade is plenty for the street and light trails, upgrading to the Currie steering may be worth looking into since you're going to be bashing it a lot.
What about moving shock mounts on this 31" build? What 2" springs give the most free length?
Ive had this built in my notes on my phone for a while now. A Rubicon killer
Project “Overkill”
Project “Overkill”
- 1” H&R Springs or Custom Eibach Springs with the longest Free Length and Dialed in Spring Rate
- Artec Rear Coil Correction Kit
- Rear Shock Outboard Mod
- Artec Front Coil Buckets w/Air Bumps
- King Air Bumps Front & Rear
- 1.25” Savvy Body Lift
- Savvy Belly up Skid
- Rubicon 4:1 Trans Case Swap
- Savvy Gas Tank Skid
- Dynatrac ProRock 44’s (Ground Clearance)
- Front & Rear ARB’s
- Powertank for Airing Up & Down
- Falken WildPeak M/T’s
- Alcoa Forged Alum Factory 15” TJ Wheels w/OMF Beadlock Added
- Black Magic Brakes Hydro Boost
- Currie Rear Track Bar
- JKS Front Track Bar
- Savvy Upper & Lower Control Arms
- Currie Anti-Rock
- Savvy Front Bumper
- Warn XD9i w/ Synthetic Rope
- PSC BFH 2 Rear Minimalist Bumper
- Savvy Sliders
- Modified Cage
- Recaro Expert M Seats
- Bestop Soft Half Doors w/ Alum Paint Matched Skins to Replace the Fabric
"Ideal" is dependent on situation and goals for the vehicle. It's different for someone who wants a cheap way to get 31s that will see mostly offroad use over a daily driven Jeep.
I have 1" H&R springs, Bilstein 5100s, JKS quick disconnects, heavier duty lower control arms, beefier than stock trackbar and steering. A few different skids and plan on a rear locker. Should be capable enough for me for some light trails and mostly street driving. Someone who wants to do more difficult obstacles might want a front locker, heavier skids, etc.
I have 1" H&R springs, Bilstein 5100s, JKS quick disconnects, heavier duty lower control arms, beefier than stock trackbar and steering. A few different skids and plan on a rear locker. Should be capable enough for me for some light trails and mostly street driving. Someone who wants to do more difficult obstacles might want a front locker, heavier skids, etc.
Is this something you found or put together yourself. Seems like its WAY overkill for the type of terrain that 31's will let you get into. I mean, sure, thats the name, but 10k+ in axles, just to run 31's? Seems like that's just spending money to spend money. A lot of the build is good stuff though, for ANY build.
Re: moving mounts, is the goal to gain articulation/travel, and therefore maintain more tire contact (avoid tires in the air)? Avoid scraping the rears?
Re: 2" springs, I'll share this info from when I was shopping.
| Spring | Free Length (inches) | Rate (lbf / in) |
|---|---|---|
| BDS 034204 | 18.50 | 158 |
| BDS 034206 | 13.75 | 200 |
| OME 2932 | 18.89 (A), 18.50 (B) | 140 |
| OME 2933 | 19.48 (A), 19.09 (B) | 140 |
| OME 2941 | 15.35 (A), 14.76 (B) | 140 |
| OME 2942 | 14.96 (A), 14.37 (B) | 160 |
| OME 2949 | 14.56 (A), 13.97 (B) | 216 |
| Pro Comp 55297 | 17.87 | 170 |
| Pro Comp 55298 | 13.54 | 175 |
As I un-build my TJ I'm finding that it may end up being a great build for 31s. I had planned to go back to all stock but certain mods that weren't worth undo-ing as well as some other factors have pushed me into a budget build.
-JKS front track bar because I drilled my mount out to 5/8" and don't have the means or determination to restore the factory taper
-unidentified springs that net about 1-1.5" lift because the guy selling them on marketplace thought they were stock and I'm tired of looking. Upside is they should work out to line up the pinion correctly with the MML I'm too lazy to remove and to get back the ~3/4" of uptravel lost due to interference between the JKS track bar and the tie rod.
-Rancho RS5000x shocks because the small lift ate too much into the downtravel available with the $30/ea Monroes from O-Reilly
-sway bar disconnects because the stock links I got from RockAuto don't fit the holes in my sway bar
-31x10.5 because they were easier to find used than 30x9.5
-AtoZ rocker guards because I'm not filling all those holes I drilled in the tub.
-MCE front fenders because I'm not buying and swapping uncut factory fenders back on
-30 and trak lok 44 with 3.73 gears, stock control arms and rear track bar from the LJ
I've actually started to hate that I have to sell it, because it's shaping up to be a pretty good conservatively built rig, but I can't financially justify keeping 2 Jeeps long term. I borrowed against my wife's 4runner to buy the LJ with the intent to pay it off with the proceeds from selling the TJ, and that payment is just a monthly reminder that I still haven't outgrown my ability to set aside good financial decision-making when I get emotional about something.
-JKS front track bar because I drilled my mount out to 5/8" and don't have the means or determination to restore the factory taper
-unidentified springs that net about 1-1.5" lift because the guy selling them on marketplace thought they were stock and I'm tired of looking. Upside is they should work out to line up the pinion correctly with the MML I'm too lazy to remove and to get back the ~3/4" of uptravel lost due to interference between the JKS track bar and the tie rod.
-Rancho RS5000x shocks because the small lift ate too much into the downtravel available with the $30/ea Monroes from O-Reilly
-sway bar disconnects because the stock links I got from RockAuto don't fit the holes in my sway bar
-31x10.5 because they were easier to find used than 30x9.5
-AtoZ rocker guards because I'm not filling all those holes I drilled in the tub.
-MCE front fenders because I'm not buying and swapping uncut factory fenders back on
-30 and trak lok 44 with 3.73 gears, stock control arms and rear track bar from the LJ
I've actually started to hate that I have to sell it, because it's shaping up to be a pretty good conservatively built rig, but I can't financially justify keeping 2 Jeeps long term. I borrowed against my wife's 4runner to buy the LJ with the intent to pay it off with the proceeds from selling the TJ, and that payment is just a monthly reminder that I still haven't outgrown my ability to set aside good financial decision-making when I get emotional about something.
Not necessarily. However, tire choices are limited and I view 32" tires like 37s. It's a weird size where if you build for them you might as well just get the next size up tire. In the case of 32, just go with a 33. For 37, just go with 40. In either case, it's the slippery slope!
My thought process was 2" suspension lift and 1" body lift would be fine for up to 32's, and that small amount of lift negates the need for a SYE, control arms, track bars, etc. Also, depending on stock gearing and/or stroker motor, you can get away with factory gearing for longer.
Couldn't agree more. I guided a friends daughter, who was driving a TJ with a TT and 31" tires, through some tough trails. She tested the skids, but went almost everywhere the rest of us on 33s and 35s went.
Keeping it light, but building it to take abuse is the intent. I already have a Savvy UA and Savvy gas tank skid for the underside. The rear will be a Rubicon 44, with a Detroit Truetrac 30 up front. I know this isn't a locker, but it's parts I have around now. There's a 44 front in the garage as well, which will be reserved for future use, if needed. I did consider the Currie steering, that's what I have on the LJ, but I also have all the new parts needed for the ZJ upgrade, so that will be going on first. I do have a set of Genright body mounts, courtesy of @Chris, but I'm going to start out with a Savvy BL.
For the topside, Savvy corners, rockers, and tail gate armor have been ordered. I'll pair those up with the rub rails that has been sitting in a box for the last 3 years waiting for a home. Approach and departure angles will be handled via a Savvy front bumper, also on order, paired with either a Savvy or Next Venture rear bumper.
What I haven't yet sorted out is the spring and shock combination!
You've seen my stuff and I'm not messing around with this one. It will get double adjustable aluminum control arms. Also, I have both a 231 on the shelf, with a JB Conversions SYE, and a 241OR. I just haven't made up my mind which it will be. Since my theme for this is light and nimble, I'm leaning in the direction of the 231. The track bars will also be replaced.
It’s just something I put together once while I was bored.
It’s overkill for sure, hence the, “Project Overkill,” name in my post as you mentioned.
I, and I’m sure you have as well, have read numerous times that some member here on 33’s or 35’s has kept up with or outdone someone on 35’s, 37’s, 38’s, etc
You have a good point and then again some people have more money to spend than others. More ground clearance than a Dana 30, high pinion, bigger and thicker tubes, available with bigger brakes, spindles and lockable hubs, custom width to offset the forged factory Jeep wheels backspacing, etc.
It’s just a much better Dana 44 which the TJ/LJ Rubicon comes with stock.
It's not out of the question. The problem I'm having is finding a progressive spring in the 2.5" and under range. Ideally, I'm looking for a progressive spring with a lighter spring rate and longer free length. If I can't find a spring that flexes with a lower lift, moving shock mounts won't necessarily add any value.
For the free length numbers, I'm seeing what @RMETeeJay posted. I couldn't find any technical specs on the H&R springs, so I sent a note to their tech support. I'm still waiting to hear back from them!
I think I should have named my project "Overkill". Like some of the things on this list, I'm working to build that "sleeper"!
Can anyone verify that the Currie steering will work with a low lift such as a 1" or 2" lift? I've read issues with the length of the tie rod, or clearance issues with low lifts.
Can't think of a progressive rate spring other than factory. JKS makes a dual rate spring in 2", but not sure what value would be gained with the light rate once the weight of the jeep in on it.
First 5 years of wheeling was on OME 2" springs and 31's. I wheeled harder on that setup than I ever have to date.
Can't think of a progressive rate spring other than factory. JKS makes a dual rate spring in 2", but not sure what value would be gained with the light rate once the weight of the jeep in on it.
First 5 years of wheeling was on OME 2" springs and 31's. I wheeled harder on that setup than I ever have to date.
So y'all are all discussing this as I'm about to start building my Jeep. I haven't wheeled it a whole lot yet, but it's stock height and I put brand 31x10.5 bfg at's on it last summer. My next step is a 1.25 savvy BL and a motor mount lift, bumpers/winch and a morryde tire carrier. Eventually I'm wanting to do a tummy tuck and sye. With the SYE would adjustable control arms be needed? I'd like to go without them for a while then upgrade to currie or something else later. I'm also in need of a track bar, I was gonna go with a moog replacement but it seems like a track bar is on most everybody's list. I don't mind being the Guinea pig to try some parts, but yall are pretty much discussing exactly what I'm planning on doing so thought I'd pitch in.
EDIT
I just read the thread Chris had about the affordable lift. I already have those exact part number shocks on the Jeep as of last year, so I'll probably get the springs and rear track bar bracket. Would the JKS front track bar be a worthwhile thing to do at the same time?
EDIT
I just read the thread Chris had about the affordable lift. I already have those exact part number shocks on the Jeep as of last year, so I'll probably get the springs and rear track bar bracket. Would the JKS front track bar be a worthwhile thing to do at the same time?
I initially looked at the Currie setup for a 1" spring lift. Here's what the notes page says:
"NOTE: This unit is designed to be used on vehicles with 4" of lift. It can be used on vehicles with less lift, but the vehicle must have a minimum of a 2" bump stop (over stock). Also, on vehicles with no lift, 2 of the tie rod ends may need be trimmed to achieve proper adjustment."
The bump stop steered, pardon the pun, me away.
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