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The (NG900/OG9-3)system has way too much rubber in it.
First thing to do is to install the heavy rear sway bar. This eliminates some nasty roll-steer artifacts from the steering. It is very effective. (It does not make the rear end more comfortable.) This makes sense as the most cost effective mod, and very simple to intall.
With the above the steering geometry will work much better, but the front end does need changes. The steering rack needs a clamp-brace kit.
The split A arm control arm setup is connected with a hollow oil filled rubber bushing that really sucks. To replace the lateral control arm needs to be removed, then the bushing can be pressed out and subjected to other implements of destruction. Then a poly bushing can be installed. The bushing at the subframe can also be removed and replaced with a quite hard poly bushing. Replacement of the bushing at the end of the arm that runs fore-aft is also important to avoid deflection of the toe-in from braking or acceleration forces. Abbott makes a steel sherical bearing for that.
These things do have a pronounced benefit. The bushings are not expensive, but the labor to press out the old ones and install new new is significant. The only steps that are common to the strut insert work is popping the ball joint stud and removal of the sway bar link. The sway bar bushing can also be replaced with poly but that has a disproportionate amount of work, expecially for DIY. The R&R of bushings is also not suitable for most DIY folks.
When you eliminate the rubber bushings, you remove the things that defected in response to the forces generated by toe-in, so that the effective toe-in when driving down the road was less than the static setting. The tires also deform to absorb some of the toe-in. When the bushings are hardened up, the much of the static toe-in is preserved when driving and that can be excessive. The toe-in settings should be reduced as the suspection bushings are firmed up. If you do not do this, then the tires will fight each other too much which will increase wear and/or create adverse wear pattern defects. In heavy rain or on ice or slush, the tires will then be in a situation where only one tires at a time will want to track properly. That could have dangerous consequences. That been said, one wants some toe-in forces to build a preload into the tire body so that steering inputs will produce an instant response, otherwise the response can feel vague/wrong.
Comfort: Most road induced vibrations are vertical and the control arm bushings are to-the-side and will not induce any increases in vibration or shock at all. The vertical loads go through the tires, bearings,steering knuckle, springs and shocks to the upper mount. The shock transmitted load vibrations go through the center of the upper mount and to its rubber surround. Note that that vertical load path does not go through the control arm bushings at all. The loads do not even go through the ball joint.
You need to replace the strut upper mounts which may be tired and cracking by now. When you fix up the suspension, you will be cornering much harder than the system was able to do in stock trim. The upper mounts do get subjected to substantial reaction forces with this increased cornering ability. I would not want to subject old mounts to those increased loads. Replacing those later is almost the same labor cost/effort as installing the struts.
Tires will become increasingly important as the limiting factor in handling. Lesser tires with higher wear ratings that scrub in the corners will wear faster than a performance tire that grips well.
As you improve the suspension, the subframe deflection becomes a limiting factor. We have seen some very good reports about the 6 point SF braces. Again, you will be increasing cornering deflection forces and the SF deflection then increases.
The Koni install suggests adding antifreeze to the strut tube to act as a heat disipation coupling fluid. I do not like that idea. I used engine oil instead. Also, the Koni insert retaining nut is very difficult to tighen up! If is gets loose, you get noise and have to remove the strut to fix that. I went through that. I then degreased the threads of the nut and the tube and used a generous amount of loctite blue.
The front struts have not enough vertical travel before you hit or are riding on the bump stops. If one lowers the springs, things get worse. This is also the major cause of bent wheels as the suspenstion goes "solid". If you cut off the lower "bulb" of the bump stops, which is probably a bit more than an inch, then the strut travel is increased and the shocks can then absorb forces over that increased distance. My experience is that this improved the ride response when things got tough. Not many folks have done this. I did that while using the stock 95SET springs+Konis+VRK.
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