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Discussion Starter · #1 ·
In full disclosure I have limited knowledge on the technical aspects of a jeep build so I'm doing research. My rig is a 2010 Rubicon.

I plan on converting to a 4BT Diesel and want to run 37's (initially I was going to go 33's but f--- it, I'm going big), but it's still my DD.

What are the benefits and drawbacks of a 3.5" X Factor mid arm suspension as opposed to a BDS long arm suspension. Front bumper will probably be a Spyder stubby and I'm going flat fenders so hopefully no scrape.

Wheels I'm thinking are the AEV Pintler Bead Lock 17" - but again I don't know any better

I assume I'll need drive shafts and a dif upgrade (currently at 4.1)

Please advise :popcorn:
 

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So a long arm will offer a lot more articulation and also enhance the on road feel of the vehicle. A mid arm will also do this, just not as much. The jk already has a sort of shorter mid arm set up stock. It's not a short arm like the TJ's had. It's a little longer than that. If you are going big and you are going to 37's and a diesel definitely go to the long arm. The drawback is cost and since you are doing a diesel, that clearly isn't a factor. Hopefully pluke chimes in cuz he has excellent knowledge of lifts and it seems like he has run or has seen every type run in person

I'm interested in hearing your progress on the diesel. This is something I'd love to do but I have several problems
-Idk where to get a 4bt diesel. I don't know of any cars/trucks/vans that have them. The 5.9l I6 cummins, sure!
-I'm wondering what kind of computer is needed to run this diesel cuz the stock one won't work on anything but your 3.8
-similarly, what transmission
-and lastly I have no idea how to get it to pass emissions

I've seen this diesel swap done only once on a 1995 YJ because that was the last year that they didn't require emissions testing on vehicles

I'm excited to see how this project works out! Keep us updated
 

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a long arm has much better on road handling characteristics. and it will have less bind in the control arms. not necessarily more flex, but if properly set up, it would have more potential than a short arm on and off the road. (same thing as a mid arm for our jks).

no doubt, that a long arm is better and nicer to have. it's just more $$ and it involves welding.

if i had to choose a long arm, i'd go with either teraflex or roll with rock krawler who have a 3 link setup that is suppose to be a flex king.
 

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See below, bud. I double posted it, on accident.
 

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I have heard that if u can find a ups truck u can pull the motor out of that and it fits in just fine but I wouldn't take my word on that. I am looking into throwing a diesel into mine also
 

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Id suggest comparing apple's to apple's on lifts. If youre interested in lifts you'd be better sticking with RK for either the long arm or mid arm, over the BDS, IMO. Flex is based on bumpstops and shock lengths, not arm lengths. General consensus is, unless you're running lots of lift, you're not going to see a lot of advantages with a longarm setup (bang for the buck). If handling is a major concern, your money would be better spent with a coilover setup over long arm (you'd see much more gains). IMO If you're keeping a correct lift for 37s 2.5", 3.5" or 4.5", save the dough and go with a shortarm or the rk midarm setup you're looking at. Only reason I'm planning on a longarm setup, is my lca mounts are getting bashed pretty good. If I'm cutting em off, might as well do longarm. I'm looking at kits that place the lca mounts inboard of the framerail and out of harms way. Plan on driveshafts with either lifts. I'm sure with your conversion, customs will be needed.

That diesel conversion will be alot of work and an absolute nightmare in ca for legality. I'm sure things are a little different in ny, but I'd cya on emissions/safety chk issues first.

Not a big fan of the pintlers for the fact of all the negative backspace. For 37's, I wouldn't recommend any wheel without at least 4.5 positive backspace. Even with 37s and 4.5 I'd rub frame rails and swaybar on full lock during flex. Smaller number equals more positive backspace IE further out from rig. My setup is 3.5" bs, though I'm running a c/o setup. I prefer plenty of clearance, without the need for spacers.

I'd definately suggest conquering one upgrade at a time. IE suspension dialed in or diesel.swap dialed in first.
 
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Id suggest comparing apple's to apple's on lifts. If youre interested in lifts you'd be better sticking with RK for either the long arm or mid arm, over the BDS, IMO. Flex is based on bumpstops and shock lengths, not arm lengths. General consensus is, unless you're running lots of lift, you're not going to see a lot of advantages with a longarm setup (bang for the buck). If handling is a major concern, your money would be better spent with a coilover setup over long arm (you'd see much more gains). IMO If you're keeping a correct lift for 37s 2.5", 3.5" or 4.5", save the dough and go with a shortarm or the rk midarm setup you're looking at. Only reason I'm planning on a longarm setup, is my lca mounts are getting bashed pretty good. If I'm cutting em off, might as well do longarm. I'm looking at kits that place the lca mounts inboard of the framerail and out of harms way. Plan on driveshafts with either lifts. I'm sure with your conversion, customs will be needed.

That diesel conversion will be alot of work and an absolute nightmare in ca for legality. I'm sure things are a little different in ny, but I'd cya on emissions/safety chk issues first.

Not a big fan of the pintlers for the fact of all the negative backspace. For 37's, I wouldn't recommend any wheel without at least 4.5 positive backspace. Even with 37s and 4.5 I'd rub frame rails and swaybar on full lock during flex. Smaller number equals more positive backspace IE further out from rig. My setup is 3.5" bs, though I'm running a c/o setup. I prefer plenty of clearance, without the need for spacers.

I'd definately suggest conquering one upgrade at a time. IE suspension dialed in or diesel.swap dialed in first.
perfectly put...
 

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Discussion Starter · #9 ·
So a long arm will offer a lot more articulation and also enhance the on road feel of the vehicle. A mid arm will also do this, just not as much. The jk already has a sort of shorter mid arm set up stock. It's not a short arm like the TJ's had. It's a little longer than that. If you are going big and you are going to 37's and a diesel definitely go to the long arm. The drawback is cost and since you are doing a diesel, that clearly isn't a factor. Hopefully pluke chimes in cuz he has excellent knowledge of lifts and it seems like he has run or has seen every type run in person

I'm interested in hearing your progress on the diesel. This is something I'd love to do but I have several problems
-Idk where to get a 4bt diesel. I don't know of any cars/trucks/vans that have them. The 5.9l I6 cummins, sure!
-I'm wondering what kind of computer is needed to run this diesel cuz the stock one won't work on anything but your 3.8
-similarly, what transmission
-and lastly I have no idea how to get it to pass emissions

I've seen this diesel swap done only once on a 1995 YJ because that was the last year that they didn't require emissions testing on vehicles

I'm excited to see how this project works out! Keep us updated
River Raider Off Road does a 4BT diesel build - i'm assuming they can get by emission standards, it's like 20K so it damn well ain't cheap, but i like it and i kept my last vehicle which i bought brand new with 3 miles on it for 16 years - so i figure it'll work for me
 

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In full disclosure I have limited knowledge on the technical aspects of a jeep build so I'm doing research. My rig is a 2010 Rubicon.

I plan on converting to a 4BT Diesel and want to run 37's (initially I was going to go 33's but f--- it, I'm going big), but it's still my DD.

What are the benefits and drawbacks of a 3.5" X Factor mid arm suspension as opposed to a BDS long arm suspension. Front bumper will probably be a Spyder stubby and I'm going flat fenders so hopefully no scrape.

Wheels I'm thinking are the AEV Pintler Bead Lock 17" - but again I don't know any better

I assume I'll need drive shafts and a dif upgrade (currently at 4.1)

Please advise :popcorn:
Well you're definitely on the right track! I can't wait to see this rig. Only heard great things about the diesel swaps. Bruiser conversions also does the swap your looking for. Depending on how much money you want to put into the suspension... IMO optimally you would want Coilovers with long arms. If installed correct, I don't see any advantages of the mid arm over the long arm. Go with the 37's for sure. If you get the 33s you'll just want 37s a couple months later. You'll at least need a front drive shaft and you'll want 5.13 gears. Also track bar adjustments and transmission cooler. I'd think about a steering stabilizer or hydraulic steering assist as well. This is gonna be a sweet setup!
 
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