[Rock Krawler Suspension]

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.

 

[thedirtman]

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

 

[thedirtman]

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.

 

[Rock Krawler Suspension]

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.

 

[thedirtman]

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?

 

[coilrod]

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

A complete waste of time sums up Rock Krawler pretty well. Your shit sucks.

 

[tapcola]

I know the rear isn't a good 3 link option but what about the front ?

Sent from my SM-N950U using Tapatalk

 

[thedirtman]

It works up front since you are one one side of the axle and have better placement of the frame side upper link mount. I prefer a 4 link up front though just for piece of mind not having to rely on a single upper link. Break that link on the trail and all kind of bad happens. I don't care for radius front either.

 

[J. Dub]

Finally someone understands me. I'm running 35's on stock suspension w/ fender flares removed and heavily cut fenders front and rear. I get shit on often by the lift guys.
Yet off road & on road I have a smoother ride compared to those JK's I've ridden in that are lifted.

 

[thedirtman]

You are a smart man, don't get frustrated with the "JK bolt on crowd", they will learn someday that you can wheel with tires smaller then 40"

 

[KOWBOY]

Yet off road & on road I have a smoother ride compared to those JK's I've ridden in that are lifted.

Most assuredly, shitty lift kits result in shitty ride quality. But a JK can be lifted and IMPROVE ride quality at the same time. Just costs a lot of money and don't bolt-on.

... you can wheel with tires smaller then 40"

Without a doubt. But daily-drivin' sucks with tires smaller than 40". :grin2:

 

[gt1guy]

The real problems that I see coming from store bought lifts, is the compromises that HAVE to be made working around all the factory bits and pieces. There's just no way around it. But, with a store bought lift, you're letting someone else make the compromises for you and, those may or may not be a compromise you'd have wanted to make on your own.

Educating yourself on how suspensions work can go a long way to help in making an informed decision in whether one companies compromises are more inline with what you're after, than another companies compromises. Being honest with yourself on the actual on road/off road time the rig will see, is something I think most people don't really do.

There was a great quote from a suspension design guru many years ago that makes a lot of sense and is simple. "Any suspension design can work if you don't let it move". That is so true.

Our problem is that we are wanting our suspensions to move, and move a lot. We want lots of up travel, lots of down travel, lots of ground clearance, and a low CG to boot. We don't want the front to lift or the rear to squat on climbs and we don't want the front to dive or the rear to lift dropping off things. We want tons of articulation off road with no body roll on road. We also want the axles to go straight up and down through they're range of travel all while keeping the pinion angle perfect and plunge on the driveshafts to a minimum.

That's a fucking tall order. You have to decide what's most important to you and go from there. Are you willing to cut and weld? Do you want to keep the Jeep pristine? Do you drive it to the trails or haul it on a trailer? Is it your daily driver or a toy?


There's a couple things on my build I did to facilitate the best of both worlds. They wont work for everybody, cutting is involved, but, I'll throw them out there anyway. One thing to keep in mind is that you only really need to use a very small amount of your total suspension travel on the street compared to off road.

Spring rates for articulation are too soft for street use, so I'm running 3 piece swaybars. I'll have a set of bars (low spring rate) for off roading and a big fat set (high spring rate) for the street. The big fat bars will eliminate the body roll on the street. It's two pinch bolts to loosen on the arms and pull out the bar, takes ten minutes. I don't even need to remove a tire to swap them out. This still gives a soft ride without the body roll, sway bars do nothing in two wheel bump.

I'm running bypass shocks. This allows me to have a set of street settings, in addition to crawling and go fast settings.

Compromises are easy, eliminating them is a lot of work, time, money, cutting, more cutting and more money.

 

[thedirtman]

Bypass shocks don't give you multiple settings for crawling or go fast unless you change the bypass valves. They allow you to fine tune zones in the shocks travel. Tuning is very important when running coil overs and bypasses and I can't see just turning knobs based on crawling or driving on the street. With as heavy a rig you have I would not think you would be running a real soft coil either. I would think you would be running a 300/400 or greater.

 

[gt1guy]

With the adjusters cranked all the way in they essentially close the check valves and don't bypass at all. This will force all the oil to go through the valve stack, effectively creating a much stiffer shock. Bypass shocks are position-sensitive, not velocity-sensitive. I only intend to play with this on the short compression and rebound tubes......the ones closest to the valve stack at ride height. My thinking is that the zone on the street is going to be maybe 3" either side of ride height.

Right now I have 175/225lb springs for the front and 150/225lb springs for the rear, all 16" over 18". That's what Ryan from Accutune recommended I start with from his program. I told him my hunk of shit would probably weigh 6k. I've only tried slapping the fronts on so far, with 1" preload, and they didn't compress but for a couple inches. Obviously I won't know exactly what my rate will need to be until it's finished........but I have a feeling it will come in way under 6k.

 

[thedirtman]

I understand how bypass shocks work, I don't get your thinking though. Crawling and street are very close to the same set up while go fast is where you need more compression and fast rebound. closing off the ride zone so it stiffens up makes no sense since you would be going from a stiff initial rate (ride zone)to a soft secondary (upper compressed) to a stiff third (bump zone) on the compression side and would want the shock to dump giving you a fast rebound. With go fast you would want a more progressive curve on the rates that restrict the oil flow as you hit bigger bumps. Of course your coils and psi in the shocks will have affect on the performance. Crawling would be the softest settings IMO so the suspension works and the coils don't lift the whole vehicle preventing articulation. On road you would be soft for comfort but also control body roll at speed so you find a balance there and you are addressing that with the swaybar system you are going to run. At the rates you listed your dual rate is around 90#-94#, if your unsprung weight was 4000# then you should have compression of 11 inches add 3" of preload should put you at 50/50 on a 16" travel shock. Not sure why you would only be getting a couple inches of compression on the fronts. My 2 door weighs in at 4000# of sprung weight I would guess you will be around 1000# or more with the amount of steel you have in your rig. I would think you would want to be closer t a 125# initial rate for mainly crawling and street and maybe a bit higher for go fast off road which you will typically see rates of 400-800 but these are purpose build for high speed, your jeep will never see these kinds of speeds. I know Ryan and he knows his stuff but I can't see you tune and set up a shock without knowing the weights of the car. Even a Couple hundred #'s will make a difference in shock performance. If you watch the ultra 4 guys race a short course and have a spare on the back is because it changes the performance.

 

[gt1guy]

I told Ryan I thought my junk would end up around 6k, that was all me. That's all he had to go off of when he sent springs. The Jeep was/is nowhere near finished when I tried slapping on the fronts just for the hell of it. So it was much lighter than it will end up, and got me to thinking it will much lighter than my initial guess when it's finished.

Luckily, I believe Ryan does free spring swaps as long as the springs aren't all chewed up. So once the Jeep is finished (in 2034) I can give him the info of where everything sits and he can do his thing. I think I really overshot with the initial weight I gave him.

 

[J. Dub]

My JKU is in the shop currently getting a comp cut on front and rear fenders (no not the fender flares, those have been long gone)
I'm on stock suspension w/ 35's (really measure 33.5" but I digress)
The local wheeling club I go out with is shaking their head. But I'm determined to go 38's w/ 0" of lift after this comp cut front & rear.
Future plans will be coilovers w/ coilover hoops poking through the hood for, you guessed it, minimal lift. Maybe an inch? Time will tell. But the hood cut will be measured once we push out the front axle, in order for the coilover hoop to have room. Then the welding begins.

OP writing this thread has been such a relief to read. To know someone exists that understands LCG is really where it's at.

 

[ALASHA]

but I have a feeling it will come in way under 6k.

My fat ass of a Jeep somehow came in at ~5850. One tons and 40s, heavy ass rear bumper and a very light front. Thats it. No fenders or aftermarket sliders. Based on that I think you will be north of 6K by quite a bit. If you somehow come in under 5850, Ill book you a flight to CO so my Jeep can go on the gt1guy diet :grin2:

But I'm determined to go 38's w/ 0" of lift after this comp cut front & rear.

Have you seen Jeep's lower 40 build from years back? If you want to run 38s with no lift and want any sort of usable up travel, its going to require a bit more than a comp cut...

 

[thedirtman]

I hope you have some wide axles. J.dub

 

[thedirtman]

I think gt1guy is talking 6000# sprung weight, hell he has 400#'s of welding wire in the hood alone.:surprise: I would suspect the whole rig will be 7500-8000#'s