Sept 17, 2009:
Why KW ClubSport is not really track worthy.
This is the year I upgraded to a new set of coilovers after having tracking and competing in a no-name Made in Taiwan brand. Frankly, I have had no problems with the no-name brand. An e46fanatic wanted to venture into the business of selling serious track only coilovers and I was one of his guinea pigs.
Reason I wanted to upgrade was to have a dual-adjustable system: rebound and compression as separate adjustments. Through a somewhat good deal, I managed a set of KW Clubsport. According to KW's website:
http://www.kw-suspension.com/en/30_Products/24_KW_Clubsport/index.php
“ This new product line is distinguished by motorsport
applications for race track and road use with ideal performance ”
I thought it was just perfect for me, ie someone who still loads up the track car and drive to/from the tracks. However ever since acquiring the KW ClubSport kit, there have been wave and wave of disappointments.
The rear springs I received in the kit are printed as KW 2003. But in the manual provided, it should have been KW 2018.
A quick call to KW and they confirmed that KW 2003 is the correct part, not KW 2018. I even spoke to one of the R&D engineers and he, too, confirmed is the correct part number. Now guess what? KW 2003 is used in KW V3 and KW V2 E46 non-M. KW 2003 has an approximate spring rate of 84N/mm. KW 2018 supposedly has a higher spring rate. 
KW 2003 is a barrel spring. That's right it's for “comfort” mostly and totally useless for the race track. And let me remind you again:
“ This new product line is distinguished by motorsport
applications for race track and road use with ideal performance ”
Now let me focus on the front coil springs. The front coil springs are printed as KW 70-170. I confirmed with the engineer that it deciphers as 70N/mm (392lbs/in) spring rate and 170mm free length. Today, I measured the spring and it's not 170mm but 140mm (5.5in).
This 5.5in length totally spoils the front height adjustment because the 5.5in coil spring is just way to short for this application. To make matters more interesting, KW includes a helper spring. Due to the 5.5” spring, I have to adjust height adjustable spring perch further up the strut to raise the front end of the car. It has come to a point that the 5.5” spring is further compressed and that in turn forces the helper spring to bind up even when the car is jacked up.
My gripe is that a so-called “distinguished by motorsport applications for race track” has only ~ 400lbs/in (front) and ~ 470lbs/in (rear)? Mind you, this Clubsport kit retails for about $3100. Sure Clubsport kit gets a pair of camber plates and somehow it is beginning to look like a slightly relabeled KW V3 + camber plates.
KW claims that the shocks are revalved for Clubsport but a repeatedly attempt to get a shock dyno comparison for V3 and Clubsport has led to no avail.
I have spoken to the KW engineer about the mislabeled springs and he has a filed a RMA for me. The correct front coil springs were sent out to me.
As you can see, it is a quality control glitch. Both are labeled 70-170 but the left one is measured as 140mm instead of 170mm. It begs the question whether the 140mm spring is still 70N or not.
To recap:
- KW misprinted information about what parts they put together for a kit. KW 2018 in manual and KW 2003 supplied.
- KW prints wrong part numbers on springs. 70-170 should have been 70-140.
- KW uses very soft springs for the Clubsport kit, which aren't really worthy for track.
So what I did do to resolve the situation?
Replace the KW 2003 and KW 70-170 with some serious linear Hypercoil springs. Currently I have 600lbs/in linear springs in the rear and 550lbs/in springs in the front.
The pointless, vile looking helper springs are gone now.
One thing I need to add. Despite the KW's subpar effort to put together a "Clubsport" kit, the KW engineer and the brand manager were extremely helpful. |