Getting frustrated, on the verge of ditching the ZJ - Page 2 -
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post #16 of 18 Old 10-20-2016, 08:49 PM
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1993 ZJ 
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Originally Posted by Timo_90xj View Post
Stock front and rear sway bars work just fine. Slightly thicker swaybars (ie. WJ front swaybar) will of course reduce body roll and add stability, but it is not a necessary upgrade.

If it is a lifted Jeep, you need to raise the trackbar mounting locations higher up - both on the frameside and axle. That will raise the IC height and reduce difference between COG height and IC height, which in turn reduces body roll.

Negative offset wheels (or wheel spacers) and wider track width sure will cause all sorts of issues, like scrub radius out-of-spec, extra load on wheel bearings, etc.. - but it does NOT increase body roll nor does it reduce sway control ability of the sway bars. If anything, it adds stability due to wider track.

Body roll is caused by the center of gravity affecting on the (virtual) pivot point of the vehicle. Instant center is in real life varying depending if one is accelerating, decelerating, going up a steep incline, etc..., but it can be calculated on a 4-link vehicle if you know certain aspects.
The smaller the distance between IC and COG heights, the less body roll you will have. Track width has nothing to do with it when talking about OEM track width vs. slightly wider stance.

Having steering & suspension components as sturdy as possinble is a good thing. Steering brace sure does help in more precice steering feel.

Why would you increase caster over stock? There is no point in that at all. On our Jeeps, you should stay as close to stock caster spec. if you want your Jeep to handle well. If you're within 5...7 it is pretty good.

i think the OP is talking about the way the jeep tends to drift in a lane on the highway. you have to constantly steer it back into the lane, and any small thing can send it drifting

after all my upgrades, mine no longer does this -- or rather, it is very slight

the caster makes the wheels swing back to straight when you let go of the steering wheel. actually i don't know what it is in degrees -- but it is probably in the high side of the range. i adjusted the left side bottom CAs all the way and lengthened the right side a 1/2". so now i trim the tracking using the right side only.

look, my jeep drives great -- so i must have done something right!!!

93 ZJ 5.2, 3.58 stroked. 242 swap. 2.5" lift. dozens of mods.
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post #17 of 18 Old 10-21-2016, 01:01 AM
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You want caster at the factory range for the best handling, best selfncentering, and preventing DW.
Steering linkage and suspension geometry aids a lot in achieving good handling.
Wider track and wider tires can cause wandering on roads that are badly worn and if your track widrh doesn't mat h the grooves on the riad.
If the tires have very sharp edges, it makes for more "squirrely" handling.

My Jeep with all the mods Icve done tracks deadnstraight, handles well and has very good steering feel. It is better than stock, and I'm not kidding. WJ steering does play a big role on that though.

Now, to the tirel wheel issue: when I had 32 x 11.50 BFG MT KM2s on 15 x 8 4" BS wheels, it drove just like it dies now with the 285/75 R16 BFG AT KO2s on 16 x 8 5" BS + 1.25" spacers.
When I change my trail tires under the Jeep (33 12.50 Cooper discoverer STTs on 15 x 8 4" BS wheels), my Jeep does not like to track and handle as well. The reason is the shape of the tire tread/ sidewall edge.

1998 Grand Cherokee 5.9 LX daily driver, 1.75" BB, 32" KM2s, HPD30 Eaton e-locker/D44a stock LSD, 4.56 gears, custom- fabbed tube bumpers and tube fenders,...

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1990 XJ Limited (4-door), 4.0 I6, AW4, NP242, ***rolled and totalled @ 165k miles***

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post #18 of 18 Old 11-02-2016, 02:27 AM Thread Starter
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1993 ZJ 
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adjusted the caster to 5.5*, didn't notice any difference.

adjusted toe to zero, then promptly went back to 1/8" toe-in as the jeep was all over the place. like sawing back and forth on the steering wheel, wow that was sketchy.

put the rear sway bar back in. still feels the same as without it other than a bit more jarring over bumps and into driveways.

i guess I'm just going to deal with the fact that ill be trailering the zj to destinations further than 100 miles from my house. I'm not in a position to start this whole project over with a wj.

thanks for y'alls input and suggestions, i appreciate it

1993 Jeep ZJ Laredo 4.0L/42RE/242/D30/D35
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