How Coil-Overs Are Made | From The KW Suspension Factory

By J.G. Pasterjak
Dec 23, 2020 | suspension, KW | Posted in Features | From the Oct. 2010 issue | Never miss an article

We were recently treated to a backstage look at KW Suspension’s plant in Fichtenberg, Germany. Not familiar with Fichtenberg? You’re not alone. 

This mostly rural town of about 2500 people sits 45 minutes or so northeast of Stuttgart. Most of the local economy revolves around farming, some tourism, and supporting the locals. On the south side of town lie the ultramodern development and production facilities of KW Automotive. Their purple and yellow trademark accents adorn the many large metal buildings that make up the KW campus, yet somehow this futuristic, industrial compound blends nicely with the scenic German countryside.

While KW may not be a household name in the States, the company is working hard to change that—which is why they invited a bunch of journalists to their headquarters. The truth is, KW is a lot more prolific in the U.S. than you may realize, as they produce coil-over kits under license for many other manufacturers. In Europe, they’re definitely one of the major players, having produced the suspensions on several recent Nürburgring 24 Hour winners.

Their story is one of success not only on track, but in the business world as well. Owner Klaus Wohlfarth started the company as little more than a storefront parts outlet, and a couple decades later KW is one of the premier suspension manufacturers in the world.

They owe a lot of their success to their development process and general philosophy. They’re not trying to crank out huge quantities and flood the market. Rather, each kit is developed from the ground up for a specific application, and all of the engineering and development are done in-house. The kit is then manufactured from high-quality materials, assembled, and packaged by hand. Finally, it’s shipped to its new home. 

That’s right, each kit is built to order by guys and girls in Germany. Cool, huh? Here’s the process as we saw it, from development through delivery:

Step 1:

Each kit begins life as a drawing on a computer in the engineering department. Here KW gets a feel for the development cycle of the kit while working out several packaging and fitting issues. Then they can move on to the prototype.

Step 2:

Klaus Frank is the head development engineer for KW, and he oversees the development of the prototype units as well as the entire project from concept to execution. (Trivia: Not all German men are named Klaus. Some are named Horst, and some are named Jurgen. We also met an Ed.)

Step 3:

A prototype kit is assembled in the KW engineering department. This kit will undergo bench testing as well as plenty of real-world development.

Step 4:

One of the best development tools KW has access to, besides Klaus Frank’s highly tuned butt (wait, that came out wrong), is this seven-post chassis dyno. This sort of testing device is usually reserved for F1 teams and OEMs. KW engineers use it to give their products a serious suspension workout in a compressed time frame, all inside a single room.

Step 5:

Frank performs the final tuning of each kit on both the road and the track. For much of their development, KW uses an excellent mountain road located minutes from their facility. Of course, there’s also the legendary Nürburgring just a couple hours away.

Step 6:

Part of the development of each kit includes loading a coil-over-equipped car with several times its rated capacity in dead weight. KW does this to check for bottoming issues. They also want to ensure plenty of suspension travel, even at lower-than-stock ride heights.

Step 7:

Once the design phase is complete, manufacturing can begin. All KW Variant 3 coil-over bodies are made from stainless steel, and they begin life as these long sections of pipe that are stored outside the machine shop.

Step 8:

Bodies are cut to length by computer-controlled saws, while other components for the assembly are machined elsewhere in the facility.

Step 9:

Once the main components exist, it’s time for assembly. One technician puts together the shaft components, while another assembles the parts in the housing. The various pieces for each unit are bar coded and organized so they can be inventoried and tracked throughout the process.

Step 10:

The final step in assembly involves filling the damper with oil, marrying the shaft to the housing, and closing the unit. Each unit is then tested on a dyno.

Step 11:

Next, the dampers go to a holding area where they await final assembly into coil-overs. These are all orders in process. KW keeps very few completed kits in stock, as most are built to order within a matter of days.

Step 12:

In the final assembly step, the rest of the coil-over components—springs, seats, upper mounts, etc.—are brought together by a technician. The coil-over is now complete.

Step 13:

Under the watchful eye of a large Pam Anderson cutout, the kits are boxed and sealed, ready for shipping. The packages also include the instructions printed in the language of the country of delivery (even Canada!). 

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View comments on the GRM forums
Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
12/24/20 12:11 a.m.

Cool stuff. yes

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