posted on March 11, 2013 00:00
Project GD STI- Checking Out The Development of KW's New 3-Way Adjustable Clubsport Coilovers
By Mike Kojima
A few months ago we visited KW Suspensions' factory in Germany to learn about the development of their new 3-way adjustable Clubsport coilovers. We feel that the 3-way Clubsport is a pivotal product for KW. The 3-way Clubsport promises the performance and flexibility in tuning of expensive elite Motorsports only shocks, that are priced out of reach of most enthusiasts in a package that is much more affordable than custom uber dampers.
The 3-way Clubsport also has something the uber dampers don't have: KW's long term street daily driving durability. Most super expensive racing dampers are designed to work ultimately well and be lightweight. Durability under long term use is not an issue because race use products are serviced frequently. The 3-way Clubsports offer the performance without compromising streetability or long term durability.
We visited KW just as they were putting the finishing touches on the development of their 3-way Clubsport to learn about the product and to attend some of its final testing. We also brought home a prototype sample set to test on our own Project GD STI. What did we learn? Look inside and see!
If you like our GD STI so far and want to see more!
|The first stop on our trip was the world famous Hockenheimring, home of the German GP every other year. We were seriously jet lagged as we flew straight from a grueling Formula D weekend straight to Germany. KW had already done a lot of the preliminary tuning of the 3-Way Clubsport on their 7 post shaker rig, their street handling loop and the autobahn prior to my arrival. Now it was time to do a track evaluation at racing speed. KW uses both Hockenhiem and Nurburgring for track testing. KW attended a track day at Hockenheim to get cheap track time just like we do. Just because it was a track day doesn't mean the KW crew was not prepared for serious shock tuning. They had brought a well organized crew and there well equipped race support van for this test.
|The van has everything needed to revalve and repair shocks including a shock dyno. The van normally attends major races across Europe to help provide race support to KW equipped teams.
|The test mule was this 997 GT2 RS. Although this is a fully registered street car, it is also a hell of a race car. A well known German VLN driver, I forget exactly who, was the test driver. The test was going to verify that the basic valving that worked well in street evaluations also worked well on the track. Let me tell you that German street conditions are more like American racing conditions! Germans drive fast. The Autobahn has no speed limit sections and there are many 2 lane twisty roads linking many towns. In Germany 70 year old grandmas can kick your ass in the twistys and it seems like everyone drives twice as fast as us everywhere.
|KW's head Engineer Klaus Frank was in charge of the test. I respect Klaus because he is the guy that introduced me to yellow lenses in my glasses. Well actually he is one of the smartest guys I know and I was eager to see how his test methods and methodology compared to how I do things. Here Klaus checks his notes to verify the car's baseline settings before heading out on the track. Did I mention that I have serious car envy? There was some serious iron at this track day and believe it or not, this GT2 RS was just a typical run of the mill car. Our neighbors in the F1 pits were a bunch of rich Swiss bankers with Ferraris and an F1 style transporter with a big crew and a hot chick to make sandwiches and espresso. There was also some sort of euro popstar driving a KTM crossbow covered in fur with a Paris Hilton like look complete with an annoying little dog. Paparazzi were snapping her every move.
|The F1 garages were way nicer that what we have at Willow Springs, Buttonwillow or even Cal Speedway! Look how neat and clean it all is. Klaus Frank was performing some last minute checks.
Monday, March 11, 2013 7:43 AM
You sure that the GT2RS was boring compared to the other cars? Looks like it is tuned by Wimmer and they have been known to make a few Porsches with 1000+ hp that have the exact same livery.
Monday, March 11, 2013 8:04 AM
Great article as always....oh and that Porsche, 'def run of the mill' :p
Monday, March 11, 2013 8:13 AM
Great read, thanks Mike! One question about the alignment- is the amount of toe out to counteract camber thrust directly proportional to camber? For example, if I have 2.5 degrees camber on my autox car, would I want .104" toe out?
Monday, March 11, 2013 10:09 AM
At this track day, what would be the coolest car at an American track day is just ho hum. There were some amazing cars. Tons of exotics and heavily modded exotics. Million dollar cars.
Monday, March 11, 2013 10:11 AM
Matt, I don't like to exceed 1/8" toe out for a higher speed car generally unless it needs it. For Autocross, I run as much as 1/4" and sometimes more like on a stock class FWD car.
It depends what the set up wants.
Monday, March 11, 2013 10:57 AM
Man, twin tubes confuse me. These things even more. What does the compression valving on the main piston look like? To put it another way, is the foot valve mostly just metering oil displaced by the shaft? And then KWs are even weirder! If there's an external reservoir, are they even really acting like a twin tube, or is the hydraulic flow path more like a monotube with a base valve... or is it an arbitrary distinction at this point?
I have no doubts of the quality nor that they do work, I'm just trying to make sense of the design choices because they're interesting.
Monday, March 11, 2013 12:03 PM
The foot valve has been basically moved to the reservoir, the Main piston is about the same. It works more like a monotube than a twin tube.
Monday, March 11, 2013 12:22 PM
Aha! That helps explain things, thank you.
Monday, March 11, 2013 4:36 PM
Sounds like I need an STi and have it Kojimmy'd.
Tuesday, March 12, 2013 1:27 AM
Nice write-up Mike,
Good to see that KW can improve on the Clubsports significantly,
since the "old" ones are quite hard to beat for a streetable suspension. I can`t wait to read about the impact of the now adjustable high-speed settings will have on the track!
Wednesday, March 13, 2013 7:13 PM
... hm. Looking up stuff on twin tubes trying to figure out how the KW valving works (before Mike said it works more monotube-ey anyway) actually gave me a whole host of ideas to try on the evolving pencil sketch design of weird mutant shock parts I've been working on. Because, oh no, it's too simple to just *buy* something...
Wednesday, March 13, 2013 7:17 PM
If you look at other super high end shock like Sachs Motorsports and some Ohlins, having coaxial tubes and reservoirs is not that unusual. The traditional definitions of twin tube and monotube are starting to become irrelevant.
Wednesday, March 13, 2013 8:06 PM
The Ohlins TTX and Dynamic DSSV (and probably others) go to a whole different length though, having the valving outside of the piston in cute little replaceable cartridges; "twin tube" but not as Koni circa 1980 would have known it. ;)
Before going any further, I feel inclined to mention I'm basically looking at KW or Turn In Concept's ASTs under my own GD. For another project though (or, really, mostly to see if I can) I'm trying to figure out if I can make really low stiction units with good valving out of a hodgepodge of commodity Bilstein, Ohlins and Penske bits and a bit of custom machining. Of course, have to finish the redesigned shock dyno first and see if I can make that work right...
Anyway, huge tangent, sorry.
Wednesday, March 13, 2013 11:02 PM
One thing I am pretty confident about is that KW will have better long term all weather street durability if that is important.
Thursday, March 14, 2013 11:22 AM
From where I sit, it's one if those "devil in the details" things. I like how TIC developed their package; fully open with explanations for their choices, dyno graphs, etc. on the other hand, I know KWs work, if not "why" as precisely. The V3s use progressive springs in back, while the spring rates on the Clubsports still scare me for winter. RCEs version of the V3s would fit the bill, but their site claims they're discontinuing the 5x100 version. I'm most heavily leaning towards V3s and throwing linear springs at them if I'm not happy with the progressive rear because of the durability aspect, but I don't know if the RCE or Clubsports versions do anything different with valving to use linear springs compared to the V3s.
That's my thought process. Yes, I know I'm making it more difficult on myself with all of this thinking, and I'd probably be happy with any of the choices I mentioned... but it's a DD, and I only want to do this once. Doing it more than once takes money away from race cars and the line.
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