Just a fresh from install, preliminary report, but initial impressions on lumpy SoCal freeways and, most importantly, BUMPS that I'm all too familiar with, are very, very good!
I can't speak in depth yet for their affect on cornering grip or twisty road handling, because the tires were rotated during the installation. It takes time for tires to scrub in to their new location. I know some people who never rotate their tires because it makes their car unstable, they just replace whichever ones that get worn out first. But I digress.
But I can comment on high speed body control and ride quality. Both are a major improvement over the stock MS3 dampers in every respect!
85mph heaves on the highway that used to just toss the car into oblivion are not a major problem anymore. Neither are rough, rotted surfaces that the car used to give up on, the tires stay planted, and I don't have to avoid every rough patch in the road anymore to maintain grip.
That said, the car still bounds a little bit more than I'd prefer, but at least the dampers catch it quickly and there's no oscillation anymore. IMO, the low frequency rebound is still a bit too soft for the MS3 spring rates, but it's a HUGE improvement over the stock dampers. I absolutely would not use these on stiffer or lower springs. The damper shafts are longer than stock, and rely on suspension travel for the FSD valving to do it's thing. They might be a good match for MZ3 ProKit's but I wouldn't recommend them for MS3 ProKit's. In fact, neither does Koni.
The good news is that even when the body stretches it's legs, so to speak, there's about another 1/2" of rebound travel in the damper to keep the tires on the ground. This is a good thing - suspension travel is your friend, on typical roads, and even lumpy race tracks. I think they put their off-road and rally experience to good use on these, they really seem to keep the tires planted over a variety of surfaces.
Low frequency compression damping is much improved. Less brake drive, less squat, and it doesn't just dive into a dip and slam into the bump stops anymore. Very happy about that, hope it keeps up as they wear in!
Meanwhile, ride quality is still firm but...better quality, is all I can say right now. It's MUCH better on poorly maintained, rutted, and eroded pavement. SoCal freeway hop is not a problem. Koni's advertising is no lie, they're just excellent road shocks for a daily driver. Overall ride comfort is better than stock, less jiggle on the small stuff but still firm. Like I said I'm going to refrain from comment on cornering until the tires scrub in, but even so, I already have much better confidence in the car. What felt like 60mph before kicks in at 90, and I'm glad the CHP had other things to do while I figured that out. I'd look down and the speedo and think, "no way." No float, no hop, no leaps and bounds, just much better stability.
There were some installation issues. The lovely gold metallic paint makes them thicker than the stocker's, which made them hard to fit into the control arm. If I were to do it again I would grind all that pretty paint away from the contact area with the front control arms and just coat it with anti-seize. From watching the install, my guess is that the coating (metallic paint, not powder coat, I suspect), is at least 1-2mm thicker than stock. Why?
Also, the kit I got had some zip ties in the packaging that are useful for nothing. A call to Koni confirmed that they were useless. The bottom of the OEM dust covers have big yellow seats for them on the OEM dampers that the FSD's lack, so they just press against the lower coil mount and don't seal as well. Koni assured me that it won't be a problem, many of their products don't even have dust covers (including all of their coilovers and the rear dampers too), and that I shouldn't worry about it. OK. I was tempted to toss them but figured that something is better than nothing.
What they failed to mention, when I had them on the phone, is that the bottom bracket of their rear dampers are just slightly too narrow for the mount on the rear end. They also have cryptic instructions and torque specs that make little sense. The lower mounts on the rears are narrower, (we didn't measure it but the wrench tells no lies) so we just cranked the bolt and hoped for the best. After 35 miles they started to rattle a bit. I don't think they'll come unhinged, but as soon as we figure out a proper fix for that, I'll let you know. Boo on Koni for that. Not good, but we'll remount them with some aircraft-grade fender washers to take up the slack.
Overall though, so far so pretty good. Once the installation issues are resolved I don't expect any problems. I'm a little tweaked at Koni for the fitment issues, cryptic instructions, and useless tech support, but the dampers themselves seem to be very good!
