Overview:
After enrolling in a few HPDEs, I was ready to look for a track suspension upgrade w/o sacrificing daily drivability. My stock sport suspension was starting to go soft after ~45K miles. It happened so gradually, I only realized after comparing to loaner cars from dealer visits.
I’m investing in this expensive upgrade to improve my track experience, but street comfort is my #1 priority, as I’m not into the lowered look. Comfort vs performance; hard to balance because it’s always a compromise, right? So why spend all this money if I’m only going to set my dampening rate so soft, it’ll only be a bit better than stock sport?
That was when Harold @ HP Autowerks mentioned a custom Swift Springs conversion for KW. I already know KW is amongst the best in street comfort, so this was interesting news for me. Swift Springs (
http://www.swiftsprings.com/advantage.html) is made from a material that not only increases available stroke, but is lighter and does not fatigue much w/ age. Sounds good, but how durable is this ‘H5S.TW’ material? Swift conducted a fatigue test that showed some aftermarket brands X, Y, Z will start to degrade (spring rate) after 200-300K compressions. In comparison, Swift springs were as good as ‘new’ after 1 million compressions. Looks good on paper, I’m sold!
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Driving Impressions:
My set arrived and it was beautiful. I was so excited and in a rush to get it installed, I took off to my mechanic w/o taking pics. I went w/ 336 lbs/in (6 kgf/mm) in the front, and 672 lbs/in (12 kgf/mm) in the rear, for best balance between daily drivability and performance (refer to spring rate sticky to compare). A track setup would be something like 450 front / 800 rear.
After it was installed, I was a little bit bummed by the look. However, I soon confirmed that my mechanic did know what he was doing, and this is the right setup for track:
http://www.e90post.com/forums/showthread.php?t=310100
So here I am w/ my first coilover set installed, and all eager to go. Equipped w/ a Wavetrac LSD (
http://www.e90post.com/forums/showthread.php?t=292510), I immediately took my car onto a freeway on-ramp. Woo hoo! …. wait, uh ... how come my car is accelerating slower? Did I lose tire pressure? OH! The car was not jerking back, haha. We’ve been so programmed to associate that little jerk w/ strong acceleration
Will take some time to adjust.
Wow the car is smooth! The stock KW V3 factory setting feels very much like stock! Even my girlfriend won't complain! When I went over bumps, the car was a little bit stiffer, but still within OEM expectations. No THUNK THUNK feeling from a stiff setup. Big thumbs up for KW's street comfort.
Ok, it's cool to have good street comfort, but c'mon, I bought this set for performance! Get on w/ the show, right?
I got home, waited for rush hour traffic to clear, and took my car out after snapping those ride height pictures in the thread above. Got to a circular, down-hill on ramp. Woo hoo, let's play! Dammit, there's a friggin Lexus SUV in front of me! ARGH! He's taking the corner pretty fast though, so one of those drivers that think SUVs are sporty.
The guy was still going too slow for me to really test my new setup. Oh what the heck. Shift into 3rd (hehe, I have too much torque for 2nd), take a quick peek into my mirrors, and VROOM! there I go!! Slight left steering adjustment placed me into the carpool lane. Smooth torque in 3rd gear and a gentle push of the gas pedal launched me past the 'sporty SUV'. Woo hoo! I'm past that sucker. Oh boy, I'm going fast.
Let's go faster.... (This is where you normally have flashes of driver being stupid and spinning out, but you gotta be there to understand how planted I felt.)
Steering wheel adjusted and locked to the right, look for the apex, look past to the exit. Uh, not losing traction. Not understeering. Wow, no body roll. Oh cool, let's add some gas and MESS up my traction. Woo hoo, car feels so solid! Crossed over into the inside lane for the ‘apex’, then let it unwind naturally back into the carpool lane for the exit as I finished the turn. No DSC lights...
Floored it.
Bye bye SUV.
Fun fun. (I would NEVER have dared trying this stupid stunt before. But somehow, you just gotta be there to understand the confidence inspired by this setup. The key word was I ‘squeezed’ the gas to shoot past the SUV, not a reckless, I floored it to shoot past the SUV.)
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In Summary:
I wrote another page of driving impressions in my excitement, describing how little body roll there was, how easy it was to correct from understeer, etc, but it got a bit long
In the end, KW V3 w/ Swift Springs AND LSD was really amazing. I took it back to the shop and had the front adjusted up to 5 from firmest (7 was factory default). Rear was left at factory default, 9 clicks from firmest. The mechanic took it out for a spin and came back with a ‘wow, the car is not as firm as I’m normally used to w/ a 5, and I’ve installed tons of KWs’. I told him this set had the Swift Springs conversion, and he was really impressed.
Comfort w/o sacrificing performance. Maybe some of you won’t feel right unless you have a firm setup, but just like me getting over the ‘no jerk’ during acceleration, a stronger ‘jerk’ doesn’t mean a car has more power, and a ‘stiff’ ride doesn’t mean the car performs better.
Hope you enjoyed the review!
PS. Heading to Infineon for 2 days this weekend. Will post track impressions after I get back!
