Of course your stock sway bar limits your suspensions travel, that’s it’s job. So it’s only natural to do someting about that to get the most out of your rig off-road. I’ve owned a few Jeeps, and never really got the point of the Anti-Rock. Sure, it sounded convenient, no more crawling under my rig to pull pins and tie things up our of the way. For the price though? I could live with the extra work at the trailhead. All that aside, when I bought my LJ, it had a broken sway bar link. The dealer replaced it for me, but it got me thinking about what to do about the sway bar. I obviously needed to do something.
So I decided to take the plunge, and buy the Currie Anti-Rock. I have to say before I continue with this article that I really like the anti-rock. It works really well on road, and off. The point here was simply to get some data, and try to put some myths to rest. I’m trying to keep this un-biased, and base the information on the data we collected.
“Myths”
The currie anti-rock limits your flex.
The flex limitation is OK, becuase all of your flex is “Useful” flex.
On vehicles with a rear sway bar, the rear should be disconnected.
My Assumptions
I believe that the anti-rock, and the stock TJ rear sway bar work together to provide balanced flex. I assumed that disconnecting one or the other may increase articulation for that axle, but then cause less articulation in the axle with the bar still connected. Causing uneven body roll.
The Test
A friend of mine, Brian, has an RTI ramp. He’s also got an interest in the anti-rock, as hes got one on his XJ. He’s also very detail oriented. He came up with some good testing mechanisms.
We got the RTI score, and we also put a magnetic angle finder on the front bumper, to get an idea of how much body roll each configuration caused.
So we collected a ramp score, and the body angle, for both test vehicles.
The Test Vehicles
The primary vehicle I wanted to test was, of course, my 2005 LJ (102.75″ wheelbase). Brian also has a very built XJ (101.5″ wheelbase) with an anti-rock in the front. He wanted to get some comparison numbers on the ramp.
The Results
LJ Fully “Connected”
Obviously I tossed my sway bar when I installed the anti-rock, so AR front, stock bar rear is my base test.
We expected the AR to limit flex, and it did.
Ramp Travel: 77″
RTI: 749
So this is basically our baseline for the LJ.
This was the worst rti score of the day. Well, except for this one (Brian’s brother in law’s stock XJ).
LJ AR Disconnected, Stock Rear Connected
This test was meant to represent the “standard” setup. If you have sway bar discos, this is representative of your setup.
Of course, we got a better score, less resistance on the suspension.
Ramp Travel:78.5″
RTI: 764
A very minimal increase, so apparently the Anti-rock isn’t limiting flex as much as I thought.
LJ Fully Disconnected
So, how does the suspension look with no swaybars at all?
Ramp Travel: 94″
RTI: 915
Woah, what? 94″? That’s a full 17″ more than with the antirock and the rear connected.
LJ Just The AR Connected
Surprisingly, the stock rear sway bar really hurt the ramp score.
Ramp Travel: 86″
RTI: 837
That’s 9″ of gained ramp travel, just by disconnecting the rear sway bar.
XJ AR Connected
This is Brian’s usual configuration. He does not have a rear sway bar.
ramp travel: 97″
RTI: 955
XJ Fully Disconnected
Disconnecting the AR gave the XJ quite a boost in rti.
Ramp travel: 113″
RTI: 1113
In Brian’s case, disconnecting the anti-rock had a much more pronounced affect. 16″ of ramp travel, that’s considerable!
Conclusions
So, in the end, the results were a little surprising. There was a definite improvement in rti scores without the AR, but we expected that. We did notice that the passenger front tire, when fully disconnected, had a pretty terrible contact patch.
The interesting thing is how much the REAR stock sway bar affected my scores on the LJ. Should I run without it? I can’t say for sure, but it warrants more testing I think. I may try runnig some trails without the rear sway bar, and see how it feels. What could go wrong?
What we didn’t expect was the lack of change in body roll! In the end there was little change in body roll on the LJ, and absolutely no change in the XJ with or without the AR. So what does that mean? Well, it’s hard to say.
On the LJ, it seemed like the rear sway bar did more to negatively affect body roll, than the AR did to improve it. With everything connected, we got 15 deg at the front bumper, with the AR disconected we got 13, with slightly more ramp travel. With the rear disconnected, the AR appeared to negatively affect body roll. This seems to make sense though. The AR would be forcing the body closer to level, and with no opposing force in the rear, the body will roll more. This was supported with the results from the XJ. With the AR connected, the body was as 20 degrees. With it disconnected, the body roll was the same, BUT the ramp score was higher. Futher up the ramp should have rolled the body more. So it stands to reason that in this configuration, the AR is actually making the body roll more. Which makes sense if you think about it.
I can say that Brian and I both firmly believe in the stability gains from the AR. You get a noticeable improvement in spine tingle when running the AR. But how do you measure that? The numbers tell me though, that without a rear sway bar to counter the front AR, you’ll actually get more body roll that without. How do you measure “usable” flex? Well, we have some ideas, but we weren’t able to test any of them out.
I think If I did this test again, I’d get another roll measurement. Pull the rig up to the same spot on the ramp and see how the body roll looks in each configuration. This would eliminate one variable. As for that spine tingle factor, testing each configuration on a sidehill or something might get a good result.
So, I guess for now.. To Be Continued..