When do I upgrade to a long arm kit from short arm? (video)
Hey guys, it's Kevin. We're going to talk a little bit today about Long Arm Kits and Lift Kits. Why you might want a long arm kit and when a regular short arm lift kit kind of runs out.
Now we're going to talk directly about the TJ, the XJ Cherokee, the WJ Grand Cherokee, and the ZJ Grand Cherokee because they're all fairly similar underneath. The WJ is a little bit different from the rest of them but the XJ, the TJ, and the ZJ are very very very similar.
Basically, around say 2-1/2, 3-1/2 inches worth of lift you're gonna start getting some pretty, what will I call it, negative results the more you lift. So basically exponentially speaking, the ride quality is going to get worse and worse and the reason is because the angle of the lower control arms. The factory lower control arms are basically parallel with the ground, when you start adding lift to it, the angle goes up substantially.
So add half an inch worth of lift, that goes up maybe a degree or two and an inch-and-a-half worth a lift goes up maybe five or so degrees. Not that much and then you start getting up into the 3-1/2 inch range and you're talking maybe, I don't know 10 or 15% or something angle on those lower control arms.
What happens is when you hit a bump, basically the axle tries to soak up that bump as best it can, supporting the frame of the Jeep above it. The higher the angle the more the axle has to kick forward at the same time as its rotating upwards. So in other words if your factory control arms were level, the axle would basically sweep directly straight up and down which really is optimal, and it even sweeps back ever so slightly at the upper range of the suspension stroke.
With 3-1/2 inches worth of lift, basically you have to come back to zero, so your axle has to move further forward to get back to parallel before it starts sweeping backwards. You can think of this as basically an arc, and the arc pivot point is your lower control arm mount on your frame. So a lower control arm that is longer would give less of an arc, that is why the Long Arm Kit rides so nice and smooth on washboard roads and highways and that sort of thing because you're allowing the axle to rotate in a more natural fashion straight up and down then if you had Short Arms. Now when you start adding more than say 3-1/2 more inches with the lift, you really start getting a really quick degraded ride quality.
Basically the cut-off point as far as I'm concerned is about 3-1/2 inches with a lift, and about the max you'd want to go on short arms. I've seen people run 61/2 inches on short arms. Can it be done, yes it can be done, but it's really a crappy ride, and you're working against physics and it's just a hell of a lot easier to just install a long arm kit. So basically, I would suggest that anything above 3 inches you might as well just graduate to a Long Arm Kit at that point, inspite of the cost.
If you want to keep it cheap and low and slow, you can just go ahead and say, you know 2 inches worth of the lift, 3 inches, or something like that and you'll be okay you know it'll still ride reasonably well if you get a really good shock and spring combo together. You know it'll ride as good as stock would have, but if you start going above that seriously start thinking about long arms and just save your pennies. I mean you could buy a whole bunch of adjustable short arm, you could adjust the front axle outwards so that you can fit your tires and you can get adjustable track bars and all kinds of different things, but the long arm kit comes with all of that stuff. So you are really spending your money twice unless you plan to only go to say 3-1/2 to 4 inches worth a lift on your short arm kit.
The way it works with most people is you know too much is never enough kind of thing. I know I've certainly done that on my own jeeps where it's like, well I'll just go you know 2 inches for now, yeah then maybe I'll bump up to like 4 and how great would it be for 6 and you know can I fit a 37 under here and you know it just - we get carried away.
I'm suggesting to you that you keep it really inexpensive until you get to the point when it's time to graduate to a long arm system and then when you do so, don't even look back. You don't have to worry about all of the the fitment issues with tires and having to trim the stuff because it won't quite fit with your factory length control arms and so on and so forth, like all of that stuff is eliminated.
So again you know 3 inches, 3-1/2 that's kind of the jumping-off point in my opinion. And you know it's again, this is mostly opinion based here. I've got a hell of a lot of experience and yet at the same time I certainly know that I don't have all the answers. I certainly know that other people have other opinions and so on so. If you got an opinion that deviates from what I'm saying, I'd love to hear from you, go ahead and post a comment and you know everybody can learn from the back and forth between us. Other than that you know just let me know how you feel about what my point is here about the whole jumping-off point for long arms vs short arms.
I'd really love to hear from some folks that have long arm kits already installed. Give me your feedback also and tell me if you think that 3 or 3-1/2 inches is a good jumping-off point or whether you think that some other number is is a good point.
My particular opinion is just simply that you can do a really inexpensive lift up to about 3 inches when you get up to about 2-1/2-3-1/2 somewhere in there, it starts getting exponentially more expensive. You could save all of that expense by just going and biting the bullet and going with the the Cadillac ride quality that you would get out of a Long Arm Kit by spending admittedly more money. But your money is going to be better spent in a better direction. You're going to get a far better bang for your buck out of, say a 1000, 2000, 3000 dollar expenditure then trying to piecemeal it together and try to get 5 inches or so and fit 33 inch tires or so and having to trim the crap out of everything and and so on and so forth.
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