KSport Coilovers: All About 'Em

[blinkwatt]

Gary in BR has/had them on his ride. I'm not sure what spring rate he is using but he said they are way too stiff for him and he's removing them.

What model K-Sport coilover did you buy? How in the world did you get them for $1k?

[j.fro]

Hey, how were you able to adjust the ride height independent of the spring perch?

[insite]

Originally Posted by j.fro

Hey, how were you able to adjust the ride height independent of the spring perch?

below the spring perch where the coilover is inserted into the wheel knuckles, there is a locking collar (on the front wheels, there is a locking collar on the very bottom of the strut, too). loosen the locking collars. then, twist the WHOLE strut. it will thread in and out of the wheel knuckle, making the entire strut shorter or longer. finally, tighten the locking collars. they need to be TIGHT; use a flathead screwdriver and a hammer to do this. BTW, if your struts make a knocking sound, these locking collars are loose.

[23109VC]

how much better are these setups than M030?

how do they stack up against M030 from a bang/buck standpoint?

for spirited street driving - i would assume these coilover systems are overkill??

[insite]

Originally Posted by 23109VC

how much better are these setups than M030?

how do they stack up against M030 from a bang/buck standpoint?

for spirited street driving - i would assume these coilover systems are overkill??

'better' has to consider application. for spirited street driving, the RoW M030 is perfect, IMO. it's even great for autocross and some track duty.

the reason i'm stepping up to a full coilover system is that i'm now able to drive beyond the capabilty of the M030 on track; the car doesn't react as fast as i can input steering corrections. additionally, this full coilover type of setup gives me more adjustability so i can dial in one setup for the street and a much more aggressive setup for the track.

it all boils down to rate of weight transfer. the M030 transfers weight in a nice progressive fashion; it's quick enough to allow a nice, sporty feel but compliant enough to really soak up bumps and irregularities in the road. the real difference with the KSports come from the increased spring rate and corresponding increase in compression and rebound damping rates.

spring rates are generally noted in force / distance. let's say i hit a bump in the road that causes a 1G force on the front left spring / damper. let's say that the static weight on that corner is 800 lb and that the bump causes an additional 800 lb force on that wheel. if my spring rate is 200 lb / in, that corner will compress by four inches. the damper will control that rate of compression and corresponding rebound. 4" is a lot of distance and will allow slower accel / decel as the chassis reacts to the bump. this is comfy. now say i double my spring rate. now, the same bump will be soaked up by only 2" of travel. if the dampers are valved in an equivalent manner for the spring rates, then the time used to accel / decel the damper is cut roughly in half. this means that the damper will feel as if it absorbs less of the bump and translates more of it to the chassis / passenger compartment. remember that in physics, 'impact' is defined as a change in momentum over a change in time. since we're halving the time, we're doubling the impact. quality dampers can mute the effect on the passenger compartment, but this will still certainly be less comfortable.

at the track, though, if i enter a corner with the stiffer springs, i get less motion, less body roll and a faster reaction time from the chassis. since the grip available on a tire's contact patch is proportional to the weight on the tire, i will have more time at peak grip in that corner (since the weight transfered there sooner) & the car will set faster, preparing to receive the next driver input earlier.

it's all about trade-offs. ultimately, my personal preference at this point is to increase the on-track capabilty of my car at the expense of street comfort. a compromise between the KSport and M030 would be the PSS9. they use progressive rate springs & lower absolute spring and damping rates. they are still great on track, but much more comfortable on the street. my personal preference here, though, was to surpass the PSS9 in spring rate & valving. additionally, progressive rate springs are nice for the road, but they translate into inconsistent handling at the track. a linear spring rate is more ideal in that setting.

man, i'm long winded today......