I considered KSports but decided against them for several reasons, listed in order of decreasing priority to me.
1. Inconsistency: I'm only going by the dyno plots and real technical, engineering-based comments I've been able to find online (an example of which is linked to in
this thread), but the fact that they have questionable quality regardless of the application was enough to raise my concerns to the point of not paying a premium for them.
2. Unavailability of supporting mods: Lower is generally better, but lowest is not best. We don't have the suspension adjustability to make extreme lowering work properly on these vehicles. Specifically, I would want at the very least a roll center adjustment kit and rear camber kit (plus an accurate point measurement method or sus layout data) before I considered dropping over 2" for a handling benefit.
3. Ride: I still plan on street driving this car often, and it already has enough interior trim rattles and impact noise on struts. There are alternative ways to make a car handle well without making the suspension super stiff, and rigid != fast.
4. Price: I paid less for new Konis, B&Gs, a professional fab and welding job on my rear subframe, equipment to perform my own alignment, and misc. supplies than one set of KSports would cost.
I'm not knocking anyone who has and likes KSports by any means; maybe they are good. After all, I did seriously consider them. They just didn't make sense to me in the end from a performance standpoint, without spending an extreme amount of extra money to have them dyno tested before shipping for peace of mind, and then having custom chassis parts made to reap the full benefits.
But enjoy whatever you choose. It's all about what makes you happy with the car anyway.
