Aside from tires one of the most critical components to your ride would be the parts you can’t even see – suspension components. Your car’s suspension is more than just springs but rather a complex network of arms, bushings, dampers and joints to keep it grounded. Roll with a worn suspension and you will get into trouble or even worse, tuners often just bolt on parts with almost no regard to tuning them. When we were looking to put a suspension on our BMW 335i Cabriolet, it had to be up to the task of keeping this hefty, yet powerful German on the road.
With dyno-proven 400whp and an impressive 412lb-ft of torque on tap, it was very easy to get the back end of this twin turbo Bimmer loose. The aim on track is to put the power down as soon as possible after you hit the apex and not get squirrelly. On track we disable the DSC and want to by-pass the electronics so we could control the car as opposed to the other way around. Now, the stock dampers were getting a little tired, and the lowering springs had an unsettling rebound. We looked around for solutions and settled on KW Suspensions Variant 2 coilovers since the V3 was too advanced and V1 too basic.
Having met KW Suspension founder Klaus Wohlfarth in Germany, I can say he is one of the most down to earth and knowledgeable suspension experts in the world. The KW Suspensions factory is nestled in quiet country side hills and you wouldn’t guess that there are 120 people diligently working inside cranking out 60,000 coilovers per year! Wohlfarth’s explanation of the KW Suspension philosophy, research and development offers huge insights as to why they are one of the industry leaders. Couple that with the achievement of stringent TÜV certification for all of their suspensions and buyers know that they can drive with confidence on one of the most capable suspensions on the market. The only surprise a KW Suspension buyer will get is the price, because they are very affordable. These KW Variant 2 coilovers for the BMW 335i have a street price of under $1700, which is excellent value for the feature that are packed in and the huge leap in resulting performance.
The install was relatively standard and started by securing the car on jack stands. Yes that is right, we decided to do this simple install in a home garage, so need to occupy a lift and pay for shop time. The wheels were removed, then the top and bottom of the struts were unbolted and pulled out. What we saw were worn struts with damaged boots so we prepared the collars on the new KW Variant 2 coilovers for a lowered ride height. We wanted to set up a fairly low ride height but still allow for some travel in the damper itself. Plus we knew the suspension was going to be tuned, so an even 2-inch drop all around was dialed-in.
Everything was torqued back down to specifications and it was time to select the proper dampening level. With the click of a dial we set it up to be stiffer in the rear to get the car to rotate a bit more in the rear end. As one German engineer put it to use the “second steering wheel” or modulating the throttle to direct the car around the corner. The front dampers had a bit more give for uneven surfaces and bumps to absorb the shock.
After our initial set-up, it was time to bump up the fun factor with a road test. The 335i was far more composed around corners and didn’t have the harsh rebound that the old setup had causing the suspension to be unloaded so much it became unpredictable. The Variant 2 is designed for enthusiasts who hit up 4-5 track days per year but want a spirited daily driver at the same time. KW Suspensions excel in this area since their ride is very smooth around city streets without the harshness of bottoming out or jarring the occupants over different road hazards. The Variant 2 has that OE feel and they have a very quiet operation with a twin tube design and all top grade components. The system boasts a special elastomer bump stop with built-in dust protection, anodized aluminum strut mounts, composite perches and a high-end Inox alloy body which will never rust. KW test units are subjected to 480hrs of salt exposure to ensure what is underneath your car stays intact over harsh winters.
It was time to hit up Can-Alignment in Waterdown, ON to get an aggressive alignment along with a corner balancing of the vehicle. Up on the scales, the corner balancing examines where adjustments can be made to distribute weight if possible. Corner balancing essentially plants the car on the road better similar to shimming up a table with uneven legs. The car will track straighter and handle better as a result with a more neutral feel. The alignment was a balance between outstanding handling characteristics and decent tire wear with just over 2-degrees of camber in the rear while maintaining that slammed look. The drive home through twisty country roads was “spirited” to say the least and crumbling city streets were no match for the ultra-smooth KWs.
On the race track at Toronto Motorsports Park, the 335i dove into any corner at far more aggressive speeds. The Variant 2s and the Can-Alignment set-up allowed for late braking and more speed carried through corners. In the end, we shaved over 2-seconds off the previous lap times and are looking to go even deeper with a more capable tire onboard.
Variant 2 Coilovers
Race Alignment and Corner Balancing