KSport Coilovers: All About 'Em

[insite]

Originally Posted by shifter997

Hi, Insite. I was reading this thread but I am not sure you installed 300/400 or 400/500. Can you let us know? How is the ride on streets/ highways?
Thanks.

i've got the 400/500 and randall has the 300/400. the 400/500 are rough on the street for sure, but not unbearable. i actually don't mind the ride at all. my fiancee really doesn't mind it either. the dampers are actually not bad; they do a good job of controlling the car over bumps and dips. i would probably choose slightly different spring rates next time to deal with some harmonic issues inherent to the 400/500 choice; probably 350/500 or 400/550, but i'm not sure yet.

[shifter997]

Originally Posted by insite

i've got the 400/500 and randall has the 300/400. the 400/500 are rough on the street for sure, but not unbearable. i actually don't mind the ride at all. my fiancee really doesn't mind it either. the dampers are actually not bad; they do a good job of controlling the car over bumps and dips. i would probably choose slightly different spring rates next time to deal with some harmonic issues inherent to the 400/500 choice; probably 350/500 or 400/550, but i'm not sure yet.

Insite, I thank you in prompt response. I appreciate your knowledge, analysis backed with calculation ( I remember " Dynamics" in Engineering class. Although I don't use it much at all ), and a fact that you track your car. Hats off to you and Randall. Thanks again.
Any word on the group buy, you mentioned in the past thread?

[RandallNeighbour]

My 300/400 setup, set at the softest setting, is just a bit rougher than stock struts and springs.

I just sorted out the installation tonight, actually. My mechanic didn't tighten down one of the top nuts on the rear driver's side strut mount (loose a 1/4 inch) and the center nut was a little loose too. Tightened both and it stopped the rattle and banging I heard while going over every bump.

BTW, if you install these, double check clearance between the coilover and your rims and tires. Before I set my rears to 25.75 inches from ground to wheel well, they were rubbing my 18x10 aftermarket Carrera lights (from wheel dynamics) just a little. Fortunately it was only rubbing on the rubber perch base on the coilover, not the spring or perch rings. My 7mm spacers are now mandatory to keep the tires and rims from rubbing in the back. I suspect they're needed in the front too.

Then, because I replaced 3 of the 4 control arms (the ones with ball joints) and all four of the other control arms (that connect to the ball jointed control arms) and installed new rear adjustable toe arms, I had some serious rubbing problems with those stinking dust shields behind the rotors. Took me forever to get them out of the way so I didn't have a very loud, tinny, ticking noise when I made U turns (from metal whacking against the holes in my cross-drilled rotors).

Having all four wheel bearings replaced at once is a real treat! The car coasts silently and finally, oh joy! I do not have steering wheel vibration any longer! After buying new tires repeatedly and having road-force balancing done more times than I can count in the last four years, I solved a vexing problem.

Now, I must wait a week to get an alignment. My mechanic said he'd do it for free if I waited until next week, so I will be patient and save $$$ to let him do it when he has time.

The car feels so very different now, but I think I hear some noise coming from the springs clattering a bit over certain kinds of bumps. The adjustment knobs are really loose in the back and cannot be removed like the front ones. I might just tape them down to see if that's what's causing the clattering back there. Everything else seems to be bolted down nice and tight.

[RandallNeighbour]

OK Ksport fans... I discovered a new problem with my coilovers. The top bolts up front are so much taller than factory that the outside ones on both sides protrude and touch the plastic cover, which has rubbed the paint off the inside of my hood.

This developed after the first hard driving day I did in the country Saturday.

I must now grind down at least one on each side to ensure that rubbing stops.

[insite]

ok, my final verdict is in on these things. i finally found a good track setup & went racing last thursday. bottom line: these are pretty good. first, a caveat: i am a VERY consistent driver, so i feel comfortable comparing my times with various equipment.

my previous best time at this track was a 1:12.7. this was done on the bridgestone RE-01R tire (1.01G standard grip) with the M030 springs, GT3 front sway and H&R rear sway. i had NO passenger and was running on fumes; the car was as light as it gets on track.

this time i was running on Fuzion ZRi tires (0.93G standard grip). these tires are generally about 7 or 8 tenths slower at this track than the RE-01R's. my first laps out, i had a full tank of gas AND a passenger; i ran ~1:13.2's. later in the day, i got down to less than 1/2 tank of gas and no passenger. also, i'd learned to drive this particular setup a bit better. i turned a 1:12.2. so, i turned a time that was 1/2 second faster on SLOWER tires. when i adjust for the tire difference, my net gain on the same tires would be about 1.3 - 1.4 seconds a lap (1.41 mile course). that is a HUGE gain for some one looking for tenths. i think i could have even done better had i had one or two more sessions.

the car is PHENOMENAL to drive now; i really loved it at the track. last time out, it was set up WAY too loose for me. this time, i went half a click softer on the rear sway and evened out my tire pressures. PERFECT!

around town, i feel like i have a setup that is reasonable enough for daily use. on the track, it's only going to get better as i refine the setup parameters.

anyone still interested in a group buy, PM me and i'll work on getting it setup. once i have the number of sets we're talking about, i'll get pricing information. i can say at this point that i recommend these coilovers, but that you should expect a STIFF car!

for those interested, here is some video from thursday:

FYI, the first lap is warm-up. the car in front of me is a 3.8L 964 race car on hoosiers. i am in a 2.5L boxster on fuzion street tires. notice he's not pulling away THAT quickly.

[insite]

oh, and out of fairness, here's my one blooper from Thursday:

http://www.youtube.com/watch?v=R8hcUpKsO8w

overcooked it just a tad!

[RandallNeighbour]

You've now got me pumped for the DE I'm going to do in December!

You know what I noticed? Very little body roll around those corners. Sweet!