My thoughts on lifts. - JKowners.com : Jeep Wrangler JK Forum
 26Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 45 Old 01-16-2019, 08:49 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews
My thoughts on lifts.

You see it posted almost everyday “new jeep owner, what lift?” and we go thru the motions of what are you going to do with it and what tire size. You also get endless posts of “I am running ***** lift and it is better then stock” along with a poser shot. I still to this day do not understand how someone can see the suspension on a rig from 25 feet away in a photo. Those two important questions to consider when doing a lift, tire size and what you plan to do with it are the keys to setting up your suspension. I am keeping these thoughts mainly on the bolt on kits for the JK.

Most of the op’s have the misconception that somehow a bolt on lift will give them more articulation or “flex” and that a lift will make the Jeep more capable off road. Most will not and some will even make them less capable in some areas when compared to the factory suspension. Reduced wheel base, coil unloading, and low roll center are just some of the things that can happen with an incomplete bolt on kit that will be detrimental to off road performance. Play around with a 4 link calculator if you want to see how much your lift is messing with the actual geometry of your Jeep. The higher you go the worse it gets too.

While a 4” lift will increase the amount of up travel you have if you don’t run a longer shock you will loose 4” of down travel for a net increase in flex of zero. Add a 2” bump stop to the above example and you just lost 2” of flex vs the factory suspension set up. I think most people have this misconception of increased flex due to the fact they usually add larger tires when they lift and that is where they are seeing the improvement off road.

Many manufactures will use names with the word flex in them to describe their arms, lift kits, or joints. These are just marketing terms and do not flex any more then another bolt on kit from other manufacturers. The “upgradeable lift” is another myth made up from the marketing team. Any lift out there is upgradeable, there is nothing special about one that advertises it as one. The term "mid arm" is also a term that is made up by a marketing team, in reality it is the same basic length as the factory arm. They use this term in comparison to the tj control arms that were really short.

I believe that a lift is needed to gain clearance for increased tire size. It can also be used to gain some belly clearance for break over angle (mainly on the 4 door) and for better approach and declination angles, although I would argue that tires should be used for these issues instead of just lifting. The bigger your tires the more total ground clearance you will have as well as improving your break over, approach, and declination angles. I understand that other factors will come into play with large tires, mainly gears, wheel bs, and fuel economy.

If you were to compare two Jeeps, one set up with a 4" short arm kit on 33" tires and one with a 2" lift and 37" tires with trimmed fenders the one on 37's, if properly geared, would run circles around the higher lifted Jeep. It would climb better, clear bigger rocks, be more stable in off camber situations, and would handle better on road due to the lower center of gravity. Both Jeeps would be the same height overall.

For me the thoughts on lifts would be to start with trimmed or flat fenders for 33’s add a 2” lift for 35’s a 3” lift for 37’s 4” for 40’s
Expect some trimming of pinch seams as your tires get larger in size.

Wheel bs should be included in the discussion as well to maintain full steering. Wheel back spacing for the previous lift recommendations on factory width axles.

Net max back spacing:
5.5” for a 33x12.5
4.5” for 35x12.5
3.5” for 37x12.5
1.75” for a 40x13.5



The Parts:

Coils:

Coils are what gives your Jeep it’s ride height, in its most simple form a lift is just longer coils or a spacer placed on top of the coils. The benefit of a longer coil vs a spacer lift is that it will have a bit more travel built into it so you can droop a bit more and run a longer travel shock. A dual rate coil is made with a light coil rate section that will compress at ride height and allow for an even longer throw at full extension allowing for the potential of increased articulation. A coil that minimizes lift and maximizes unloaded length will give you the most benefit for increasing flex and off road performance.
One drawback from a coil that is really long is unloading that occurs on a steep climb or decline when the coils push the jeep away from the axles and give you the possibility of flopping onto the roof. Limit straps and suck down winches can help with that problem. ORI struts have a built in feature that eliminate this problem as well.

Shocks:

Shocks control the compression and rebound of the coils, quality of the ride, and the upper and lower limit to a suspension. To increase articulation, total travel is what you are looking for. Typically for 33”-35” tires you will be looking at a 10” travel shock. With 37”-40” a 12” travel shock will do. These are for bolt on kits, if you want to get adventurous and are willing to cut and weld 14”-16” are doable with considerable effort.

When running a longer travel shock you will have to take into account the rotation of the axle when one wheel is drooped and one is stuffed. The stuffed wheel will travel farther into the wheel well and you will experience more axle shift where a driveshaft may make contact with the fuel tank or oil pan.



Bump Stops:

Bump stops are there to keep your tires and other suspension components from rubbing on fenders and the frame. They are also used to keep shocks from totally compressing which can potentially damage them. When adding larger tires or doing a drag link flip you will need to add bump stops to keep things from rubbing. You can also trim fenders or notch the frame to gain extra up travel. Remember when adding bump stops you are limiting your up travel and are reducing your flex. Trimming fenders or running flat fenders is a good way to increase flex if tire rubbing the fenders is your limiting factor vs running longer bump stops.

Limit Straps:

Limit straps limit your down travel and can reduce your flex. However If set up properly the limit strap will prevent your shocks from totally extending, potentially damaging them, and can actually allow you to increase flex by overcoming the limitations of other components such as the drive shafts. By placing a limit strap at the differential you can limit the angle of the u joints or keep a driveshaft from making contact with the exhaust cross pipe while still allowing more droop at the wheels so the axle can rotate over obstacles. I have not seen a single lift that offers limiting straps, though they should be in every kit over 3” at least at the front driveshaft.

Sway bars and links:

While most of you disconnect your sway bars when off roading, (I don’t run them at all but my set up is far from a bolt on) should you run off road with them connected you run the risk of flipping your sway bar forward if your sway bar links are too short. This will lock up your steering and will likely bend stuff. They should be sized so they are +- 5 degrees from level. I would error at the +5 if it were me as I have flipped mine a couple of times when I over extended the front end.

Disconnecting the links will give you more potential travel in your suspension but will also make it less stable in off camber situations. After market sway bars like the TeraFlex duel rate or the Currie anti-rock will give you extra stability while having a softer twist rate for articulation.

Track Bars:

Track bars keep your axles centered on the Jeep. As you articulate your suspension the axle will shift from side to side. When you droop the front the axle moves to the driver side. The opposite happens on the rear. As you lift the track bar becomes more angled and due to that angle will shift more then a stock or level track bar. The track bar also determines your roll center. This is a line drawn thru the center of the front and rear track bars to determine how the vehicle will roll on its suspension from side to side. Think of a top heavy feeling from a low roll center. Raising the rear axle side track bar bracket will increase the roll center and make the Jeep feel more stable during off camber situations and on road cornering. The front track bar needs to stay parallel to the drag link for proper steering geometry and only should be raised when in combination of a drag link flip (done typically at 3.5”+ of lift). Many bolt on lift companies will give you an adjustable front track bar to re-center your axle and a raised rear axle side bracket that raises the track bar mount by the same amount as the lift which will center the axle with the factory track bar. Some of the manufacturers that make lower end kits will address the track bar issue by including a frame side lowering bracket as well as a drop pitman arm. While this will correct the steering geometry, it will lower the roll center of the Jeep making it less stable in cornering on road and more tippy in off camber situations. The drop pitman arm will also increase the stress load on the steering box and can lead to bent sector shafts as well as leaking seals on the steering box.

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
Sponsored Links
Advertisement
 
post #2 of 45 Old 01-16-2019, 08:50 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

Fixed Length Control Arms:

These are offered on some lower priced kits to keep the cost down while correcting suspension geometry (mainly caster) for the amount of lift in the kit. They typically use the same low priced clevite joint that the factory arms use.

Rod End Joints:

End joints are used to help comfort the ride from vibration and give it some flex in the connection point to allow for articulation. The more the misalignment built in the joint the more flex you can do without putting stress on the control arm mounts. Will some joints allow for more articulation then others? The answer is yes in theory but when installed on the JK factory brackets all aftermarket joints will perform about the same due to other constraints on the JK that limit articulation. This is one of the areas of a lift kit that can really bump up the cost. If a lift manufacture used 16 Johnny joints vs the factory style clevit joint the cost difference would be in the $500 range. A double adjuster on a control arm will increase the costs roughly $35 per arm.

Steering:

Steering linkages is another discussion for another day but will play a part in lifts 2.5” and taller.

Just for disclosure, I have never actually purchased a "lift kit" although I have installed them on others rigs.

These are just my thoughts on lifts after years of messing around with TJ’s and JK’s other people may have different thoughts and experiences and feel free to jump in the discussion. I would prefer the discussion to concentrate on bolt on kits for the JK and not suspension theory of rock bouncers and koth rigs.


Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
post #3 of 45 Old 01-16-2019, 09:01 AM
Granite Guru
 
Join Date: Sep 2017
Posts: 105
Garage
Feedback: 0 reviews

Quote:
Originally Posted by thedirtman View Post
You see it posted almost everyday “new jeep owner, what lift?” and we go thru the motions of what are you going to do with it and what tire size. You also get endless posts of “I am running ***** lift and it is better then stock” along with a poser shot. I still to this day do not understand how someone can see the suspension on a rig from 25 feet away in a photo. Those two important questions to consider when doing a lift, tire size and what you plan to do with it are the keys to setting up your suspension. I am keeping these thoughts mainly on the bolt on kits for the JK.



Most of the op’s have the misconception that somehow a bolt on lift will give them more articulation or “flex” and that a lift will make the Jeep more capable off road. Most will not and some will even make them less capable in some areas when compared to the factory suspension. Reduced wheel base, coil unloading, and low roll center are just some of the things that can happen with an incomplete bolt on kit that will be detrimental to off road performance. Play around with a 4 link calculator if you want to see how much your lift is messing with the actual geometry of your Jeep. The higher you go the worse it gets too.



While a 4” lift will increase the amount of up travel you have if you don’t run a longer shock you will loose 4” of down travel for a net increase in flex of zero. Add a 2” bump stop to the above example and you just lost 2” of flex vs the factory suspension set up. I think most people have this misconception of increased flex due to the fact they usually add larger tires when they lift and that is where they are seeing the improvement off road.



Many manufactures will use names with the word flex in them to describe their arms, lift kits, or joints. These are just marketing terms and do not flex any more then another bolt on kit from other manufacturers. The “upgradeable lift” is another myth made up from the marketing team. Any lift out there is upgradeable, there is nothing special about one that advertises it as one. The term "mid arm" is also a term that is made up by a marketing team, in reality it is the same basic length as the factory arm. They use this term in comparison to the tj control arms that were really short.



I believe that a lift is needed to gain clearance for increased tire size. It can also be used to gain some belly clearance for break over angle (mainly on the 4 door) and for better approach and declination angles, although I would argue that tires should be used for these issues instead of just lifting. The bigger your tires the more total ground clearance you will have as well as improving your break over, approach, and declination angles. I understand that other factors will come into play with large tires, mainly gears, wheel bs, and fuel economy.



If you were to compare two Jeeps, one set up with a 4" short arm kit on 33" tires and one with a 2" lift and 37" tires with trimmed fenders the one on 37's, if properly geared, would run circles around the higher lifted Jeep. It would climb better, clear bigger rocks, be more stable in off camber situations, and would handle better on road due to the lower center of gravity. Both Jeeps would be the same height overall.



For me the thoughts on lifts would be to start with trimmed or flat fenders for 33’s add a 2” lift for 35’s a 3” lift for 37’s 4” for 40’s

Expect some trimming of pinch seams as your tires get larger in size.



Wheel bs should be included in the discussion as well to maintain full steering. Wheel back spacing for the previous lift recommendations on factory width axles.



Net max back spacing:

5.5” for a 33x12.5

4.5” for 35x12.5

3.5” for 37x12.5

1.75” for a 40x13.5







The Parts:



Coils:



Coils are what gives your Jeep it’s ride height, in its most simple form a lift is just longer coils or a spacer placed on top of the coils. The benefit of a longer coil vs a spacer lift is that it will have a bit more travel built into it so you can droop a bit more and run a longer travel shock. A dual rate coil is made with a light coil rate section that will compress at ride height and allow for an even longer throw at full extension allowing for the potential of increased articulation. A coil that minimizes lift and maximizes unloaded length will give you the most benefit for increasing flex and off road performance.

One drawback from a coil that is really long is unloading that occurs on a steep climb or decline when the coils push the jeep away from the axles and give you the possibility of flopping onto the roof. Limit straps and suck down winches can help with that problem. ORI struts have a built in feature that eliminate this problem as well.



Shocks:



Shocks control the compression and rebound of the coils, quality of the ride, and the upper and lower limit to a suspension. To increase articulation, total travel is what you are looking for. Typically for 33”-35” tires you will be looking at a 10” travel shock. With 37”-40” a 12” travel shock will do. These are for bolt on kits, if you want to get adventurous and are willing to cut and weld 14”-16” are doable with considerable effort.



When running a longer travel shock you will have to take into account the rotation of the axle when one wheel is drooped and one is stuffed. The stuffed wheel will travel farther into the wheel well and you will experience more axle shift where a driveshaft may make contact with the fuel tank or oil pan.







Bump Stops:



Bump stops are there to keep your tires and other suspension components from rubbing on fenders and the frame. They are also used to keep shocks from totally compressing which can potentially damage them. When adding larger tires or doing a drag link flip you will need to add bump stops to keep things from rubbing. You can also trim fenders or notch the frame to gain extra up travel. Remember when adding bump stops you are limiting your up travel and are reducing your flex. Trimming fenders or running flat fenders is a good way to increase flex if tire rubbing the fenders is your limiting factor vs running longer bump stops.



Limit Straps:



Limit straps limit your down travel and can reduce your flex. However If set up properly the limit strap will prevent your shocks from totally extending, potentially damaging them, and can actually allow you to increase flex by overcoming the limitations of other components such as the drive shafts. By placing a limit strap at the differential you can limit the angle of the u joints or keep a driveshaft from making contact with the exhaust cross pipe while still allowing more droop at the wheels so the axle can rotate over obstacles. I have not seen a single lift that offers limiting straps, though they should be in every kit over 3” at least at the front driveshaft.



Sway bars and links:



While most of you disconnect your sway bars when off roading, (I don’t run them at all but my set up is far from a bolt on) should you run off road with them connected you run the risk of flipping your sway bar forward if your sway bar links are too short. This will lock up your steering and will likely bend stuff. They should be sized so they are +- 5 degrees from level. I would error at the +5 if it were me as I have flipped mine a couple of times when I over extended the front end.



Disconnecting the links will give you more potential travel in your suspension but will also make it less stable in off camber situations. After market sway bars like the TeraFlex duel rate or the Currie anti-rock will give you extra stability while having a softer twist rate for articulation.



Track Bars:



Track bars keep your axles centered on the Jeep. As you articulate your suspension the axle will shift from side to side. When you droop the front the axle moves to the driver side. The opposite happens on the rear. As you lift the track bar becomes more angled and due to that angle will shift more then a stock or level track bar. The track bar also determines your roll center. This is a line drawn thru the center of the front and rear track bars to determine how the vehicle will roll on its suspension from side to side. Think of a top heavy feeling from a low roll center. Raising the rear axle side track bar bracket will increase the roll center and make the Jeep feel more stable during off camber situations and on road cornering. The front track bar needs to stay parallel to the drag link for proper steering geometry and only should be raised when in combination of a drag link flip (done typically at 3.5”+ of lift). Many bolt on lift companies will give you an adjustable front track bar to re-center your axle and a raised rear axle side bracket that raises the track bar mount by the same amount as the lift which will center the axle with the factory track bar. Some of the manufacturers that make lower end kits will address the track bar issue by including a frame side lowering bracket as well as a drop pitman arm. While this will correct the steering geometry, it will lower the roll center of the Jeep making it less stable in cornering on road and more tippy in off camber situations. The drop pitman arm will also increase the stress load on the steering box and can lead to bent sector shafts as well as leaking seals on the steering box.
Great write up

Sent from my SM-N950U using Tapatalk
tapcola likes this.
stevenjoh1972 is offline  
Sponsored Links
Advertisement
 
post #4 of 45 Old 01-16-2019, 09:10 AM
Wheeler
 
NeverLift's Avatar
 
Join Date: Feb 2015
Posts: 60
Feedback: 0 reviews

When I have some time I will read through your post and if you want I can PM you some of my thoughts.
I have lifted a few jks and have made list for people looking to buy lifts/tires.
My jeep is pretty much all "custom". my lift uses heims, dom and ruff stuff brackets.

Sent from my SM-G935V using Tapatalk
stevenjoh1972 likes this.

Last edited by NeverLift; 01-16-2019 at 09:20 AM.
NeverLift is offline  
post #5 of 45 Old 01-16-2019, 09:12 AM
Cod
JKO Addict!
 
Cod's Avatar
 
Join Date: Jun 2010
Location: Tennessee
Age: 50
Posts: 3,739
Garage
Feedback: 2 reviews
Send a message via MSN to Cod

Can a mod Sticky this??

Quote:
Originally Posted by bsack View Post
We liked you better when we didn't know you. If you just fucked off we could go back to not giving a shit about you.
Cod is offline  
post #6 of 45 Old 01-16-2019, 10:32 AM
Super Moderator
 
j3ff3ry_j33p's Avatar
 
Join Date: Jul 2012
Location: Nashville
Posts: 6,060
Garage
Feedback: 1 reviews

Quote:
Originally Posted by Cod View Post
Can a mod Sticky this??



^x2 on this request.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
j3ff3ry_j33p is offline  
post #7 of 45 Old 01-16-2019, 11:33 AM
JKO Addict!
 
gt1guy's Avatar
 
Join Date: Sep 2012
Location: New Iberia, La.
Posts: 3,914
Garage
Feedback: 0 reviews

Quote:
Originally Posted by Cod View Post
Can a mod Sticky this??
First you have to start talking about guitars to get his attention.

I think Jeffery should be a mod.
Cod likes this.

Kevin
gt1guy is offline  
post #8 of 45 Old 01-16-2019, 03:08 PM
Granite Guru
 
Mason's Avatar
 
Join Date: Nov 2014
Location: Warkworth, On
Age: 29
Posts: 363
Garage
Feedback: 0 reviews

Quote:
Originally Posted by gt1guy View Post
First you have to start talking about guitars to get his attention.

I think Jeffery should be a mod.
Yamaha, Gibson, Les Paul. Is that good enough?

2012 JKU Rubicon - Build Thread -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Mason is offline  
post #9 of 45 Old 01-16-2019, 06:01 PM
Granite Guru
 
MicroMark's Avatar
 
Join Date: Nov 2010
Location: Manassas, VA
Age: 56
Posts: 140
Feedback: 0 reviews

Thank you for taking the time to write that up. Helped me to understand some issues I'm having with my lift...

"It's not the critic who counts..." T. Roosevelt
MicroMark is offline  
post #10 of 45 Old 01-17-2019, 05:39 AM
Cod
JKO Addict!
 
Cod's Avatar
 
Join Date: Jun 2010
Location: Tennessee
Age: 50
Posts: 3,739
Garage
Feedback: 2 reviews
Send a message via MSN to Cod

Quote:
Originally Posted by gt1guy View Post
First you have to start talking about guitars to get his attention.

I think Jeffery should be a mod.

My bad forgot about that let's see here.


My younger than me wife and my dead rat just bought me the best old school Gibson guitar, but I don't play them so if only I knew of someone who plays and loves guitars that I could give this to...… any thoughts @StubEXrube oh and while you're here maybe sticky...or not
RUCKDOG and j3ff3ry_j33p like this.

Quote:
Originally Posted by bsack View Post
We liked you better when we didn't know you. If you just fucked off we could go back to not giving a shit about you.
Cod is offline  
post #11 of 45 Old 01-17-2019, 06:25 AM
Super Moderator
 
j3ff3ry_j33p's Avatar
 
Join Date: Jul 2012
Location: Nashville
Posts: 6,060
Garage
Feedback: 1 reviews

Quote:
Originally Posted by gt1guy View Post
First you have to start talking about guitars to get his attention.

I think Jeffery should be a mod.




I'd be honored plus gentle and fair...




Just scream ,
" @StubEXrube !!
Free lubrication !
Free Dean Markley strings!
There's a dead rodent in the cowling!!! "

that'll usually bring him around ....


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
j3ff3ry_j33p is offline  
post #12 of 45 Old 02-01-2019, 11:19 AM
JKO Addict!
 
gt1guy's Avatar
 
Join Date: Sep 2012
Location: New Iberia, La.
Posts: 3,914
Garage
Feedback: 0 reviews

I just noticed this is a sticky now. Cool.
j3ff3ry_j33p likes this.

Kevin
gt1guy is offline  
post #13 of 45 Old 02-01-2019, 02:37 PM
Granite Guru
 
Join Date: Aug 2010
Location: Brisbane Australia
Age: 53
Posts: 359
Garage
Feedback: 0 reviews

Thank you for compiling this Dirtman. This article will be used as my 'go to' when purchasing new parts...
Rodjk is offline  
post #14 of 45 Old 02-02-2019, 09:37 AM
Newbie
 
Join Date: Jul 2018
Posts: 2
Feedback: 0 reviews

Thx for a great post. Very good info.

Trimis de pe al meu LYA-L29 folosind Tapatalk
XTra is offline  
post #15 of 45 Old 04-30-2019, 10:33 PM
Wheeler
 
Join Date: Mar 2019
Location: Western WA state
Posts: 19
Garage
Feedback: 0 reviews

Thanks Dirtman! I've been eyeballing my bumpstops and wondering if they were too long. I will have to check it out when I get a chance soon.
SteveRN is offline  
post #16 of 45 Old 11-24-2019, 07:52 PM
Rock God
 
tapcola's Avatar
 
Join Date: Jan 2013
Location: Las Vegas
Posts: 1,103
Feedback: 0 reviews

Thoughts on 3 links?

Sent from my SM-N950U using Tapatalk

SYNERGY, FOX,VKS,HUTCHINSON,
tapcola is offline  
post #17 of 45 Old 11-24-2019, 08:53 PM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

I ran a 3 link rear for a while and did not like it. Felt too loose in the rear. Hard to get good geometry with the frame side upper mount being so high due to the drive shaft. Requires you to run a really high bridge and then you loose available up travel. This is likely why you don't see many manufacturers offer the 3 link.

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
post #18 of 45 Old 11-24-2019, 09:04 PM
Rock God
 
tapcola's Avatar
 
Join Date: Jan 2013
Location: Las Vegas
Posts: 1,103
Feedback: 0 reviews

Quote:
Originally Posted by thedirtman View Post
I ran a 3 link rear for a while and did not like it. Felt too loose in the rear. Hard to get good geometry with the frame side upper mount being so high due to the drive shaft. Requires you to run a really high bridge and then you loose available up travel. This is likely why you don't see many manufacturers offer the 3 link.
Makes sense ,we recently had a big event in logandale . I was trying to get this guy in a JLU on tons and 40s threw a big v notch that's shaped like a z . He had a front and rear 3link . It traked like crap! I had gotten half a dozen rigs through with no problem. But the 3link sucked balls.
(So did the driver )but still the rear just didn't follow well with full flex.

Sent from my SM-N950U using Tapatalk

SYNERGY, FOX,VKS,HUTCHINSON,
tapcola is offline  
post #19 of 45 Old 11-25-2019, 08:30 AM
JKowners Vendor
 
Rock Krawler Suspension's Avatar
 
Join Date: Apr 2009
Posts: 4,717
Feedback: 8 reviews

If you bring into the discussion the mechanical advantage increase for a given tire to climb an obstacle it may help those who don't understand how a 2.5" lift with flat fenders and 37's will out perform a 3.5 or 4.5" lift with stock fenders and 35's on a given vehicle.

The misconception of the bridge height of a 3 link versus a 4 link is just that. If you are putting an arm and given joint size above the differential it takes up the same spaces wether that be a 3 link or a triangulated 4 link. You can achieve your desired instant centers and roll centers with either set up. With the triangulated 4 link you will position all your control arm mounts to achieve the desired IC and RC. With the Independent 3 Link you will position the upper arm mounts and lower arm mounts to achieve the desired IC and the track bar mounts will achieve your desired RC. This just satisfies theories or packaging requirements. The "how it feels" will also be affected by spring rates, shock rate and positioning, and sway bars. All of those things need to come together wether you are doing a Independent 3 Link or Triangulated 4 Link arrangement.
Rock Krawler Suspension is offline  
post #20 of 45 Old 11-25-2019, 11:41 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

There is no misconception. On a 3 link like yours you have to build around the frame upper link which is above the driveshaft. With this being fixed it limits where you can put axle and frame lower brackets so you can increase ground clearance. If you move the lower links up for clearance then your geometry goes out the window. If I put your single upper link in where you do I would get -1% anti squat, in order to get it close to where I am at 74% anti-squat I would have to raise the axle side upper mount up around 3". To compensate for a -1 anti squat I would have to run a really high rate coil that would ride rough and would not compress very good under articulation. You could also run a high rate sway bar to help with stabilization but then again you compromise articulation.

With my set up I can run 7" of up travel and have more ground clearance with a low coil rate and a 2 door anti rock. I am 78" to the top of my windshield for reference on lift height. On road my ride is very nice and off road the suspension really soaks up bumps without the side to side jarring ride I have experienced in every jeep I have rode in with a RK 3 link. I also have better clearance under the jeep and axle and don't have the axle shift you get with running a pan hard bar. Is not the main reason to run big tires and lift to gain clearance and articulation?

Yes your 3 link allows you to run a long arm and retain the factory tank but has many compromises to do it in terms of ride quality and tracking. And again if a 3 link was so great why does not every manufacturer have one?
Will Scarlet and tapcola like this.

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
post #21 of 45 Old 11-26-2019, 07:47 AM
JKowners Vendor
 
Rock Krawler Suspension's Avatar
 
Join Date: Apr 2009
Posts: 4,717
Feedback: 8 reviews

Just so you know

RE, TNT and a few others have 3 links. Why do most companies run long lowers and short uppers that don't even comply to the 80% thumb rule? That is a better question.

Harsh ride is something we never hear regarding our long arms. Ride quality can be tuned to just about any suspension geometry. We try to stick to general factual information and not opinions. We were speaking in general discussion terms. Not talking brands, not talking anything other than general terminology.

Where did you mount your upper arms for your triangulated 4 link? Shoot a pic please. That would be very helpful for all to see.

Every factor of suspension can be tuned as stated in our prior post. We run all forms of suspension geometry in many many applications! In our last race rig we actually ran a reverse triangulated 4 link in the rear on the JK-R which in my opinion is the optimum suspension geometry in the rear by far. That is just my opinion though. With that geometry you have the most amount of up travel available, but it does require a fuel cell either inside the vehicle or behind the rear axle which is illegal in all states! Federal law requires any vehicle on the road to have the fuel tank located between the axles since 2007.

X2 Geometry for the rear of the JK gets released Jan 1. This is based off our Trail Runner and Trail Demon geometry in the rear and matches what we have done in the JL.

If you are talking an off road only vehicle, sure a lot of things come into play and if you want to wheel your rig against our JK-R we are down for sure.

But if we are referencing street driven vehicles we have to ensure they are compliant with Local and Federal Laws.
Rock Krawler Suspension is offline  
post #22 of 45 Old 11-26-2019, 08:26 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

my uppers are mounted as high as they can be mounted under the tub in the corner of the frame, If it were in the same spot as your center mounted 3 link it would hit the driveshaft. Yes I rip on kits like the Teraflex long arm that uses really short uppers and has crazy pinion angle changes under articulation and I think their speed bumps are a joke and they rip people off with them. I am not a big fan of the 80% rule either, I think the upper and lower links should be closer to length then that and your goal should be to put the frame mounts as close to the output shaft as you can. I typically build with uppers being longer then lowers.

Your trail runner was the worst riding lift I have ever been in. There is a video posted and we have been thru this before, not looking to relive it. You guys blamed it on the shock oil and 32 degree weather even though the jeep was stored in a heated building before the test run.

My rig is not an off road only and runs on the road way more than off. AS far as legal, sell a lot of Illegal lifts around the country that cause the vehicles their on to violate many state and local laws.

Have great thanksgiving

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
post #23 of 45 Old 11-26-2019, 09:21 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

In all truths I would not recommend a long arm to anyone as you can buy a short arm 2.5" lift from metalcloak that will out flex any other lift offered that takes a fraction of time and cost to install and would have a superior ride on road and off.
tapcola likes this.

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
post #24 of 45 Old 11-26-2019, 09:56 AM
JKowners Vendor
 
Rock Krawler Suspension's Avatar
 
Join Date: Apr 2009
Posts: 4,717
Feedback: 8 reviews

The Trail Runner is completely tunable by the end user as is every coil over or advanced system like that. I don't need to say anymore there. If you were a part of the tuning process well..... No need for us to be negative. That older system did not have the X2 Geometry for the rear that is coming out for Jan 1. It is very similar to what we have done on the JL and will make sure RK has a nice family of product.

You turned an open discussion on geometry into your opinion once again. A complete waste of time...

You too have a good Thanks Giving.
Rock Krawler Suspension is offline  
post #25 of 45 Old 11-26-2019, 10:07 AM Thread Starter
JKO Addict!
 
thedirtman's Avatar
 
Join Date: Aug 2010
Location: southwest reno, nv
Age: 52
Posts: 4,456
Feedback: 0 reviews

You brought up the trail gunner and no I wan not in on the tuning. Professional shop tuned but poor instructions and lack of phone support didn't help with your bypasses. Months down the road it turned out one bypass was bad but still does not ride good. I should track down the owner and try the ride again. He has installed tons on it now and I am curious how it rides with the extra weight. As far as geometry with the trail gunner, basically the same as your other 3 links rear and the front has too little separation at the frame side links, I am thinking it was between 3"-4". 25% rule should put you 7"-8" at the frame. I know the front is tough on geometry as there is just too much stuff up there but if you are going to have the rear links hanging as low as you do and using the low axle side front mounts why not drop the lowers a bit to gain some more separation and flatten the lower links some for less axle shift.

Why is it that you guys put out kits with all kinds of welding required and don't do anything with the lower control arm mounts to increase ground clearance?

Some build info here:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


[COLOR="Red"]New to jeeps, check this link
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
thedirtman is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JKowners.com : Jeep Wrangler JK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome