When modifying a vehicle for track use, the first thing that is most often upgraded is the suspension. Our E46 M3, Project M-Track3r, had a good, street-focused coilover system that the previous owner installed, but for the purpose we’re going to use this car for, we wanted to take our suspension setup to the next level.
For Project M-Track3r, we wanted a suspension system with a lot of adjustability for track days, as well as street driving, so we went with Bilstein‘s Clubsport coilovers. With a long, successful history in motorsports from Formula 1, to the Baja 1000, to Le Mans, we knew that Bilstein would be a great choice for our soon-to-be track monster. Follow along as we install Bilstein’s Clubsport coilovers on our E46 M3.
Looking at Bilstein’s Clubsport coilover kit, there’s no denying the lack of quality in such a compact package. Bilstein has been around for quite some time and has had great success in both racing and street applications with the monotube design. “The monotube construction provides excellent cooling for a long life with consistent performance,” explained Regis Finn of Bilstein.
For those aren’t aware, Bilstein also has partnerships with some of the world’s leading automobile manufacturers. For those applications, the quality must be up to the manufacturer’s standards in terms performance and reliability. That being said, it’s safe to say that they provide the same quality in their aftermarket coilovers as they do for their OE products.
The shocks can be adjusted for both compression (blue) and rebound (red) via two knurled aluminum adjustment knobs. Each knob is numbered from 1-10; 1 being the softest setting and 10 being the stiffest setting. The front adjustments are made from under the front strut.
The rear adjustments are made from the top of the shocks, which protrude into the trunk. These adjustment locations are great for quick suspension changes and tuning on the fly. With 10 settings for compression and rebound, there more than 100 unique suspension settings to tune for a bumpy track, smooth track, and the ride home. Being able to make adjustments for compression and rebound in a coilover system is crucial because if there was only one setting for multiple scenarios, the system wouldn’t perform great at all.
For example, When a car drives over a bump in the road, the wheel is pushed up into the wheel well, compressing the spring. That is the compression stage of the shock. Once the spring hits its peak compression, the shock must slow down the movement of the spring as it exerts its tension. That is called rebound. Without compression or rebound, the suspension would be bouncy and the driver would feel a lot of unwanted vibration throughout the car.
Camber is another big aspect in suspension geometry, which is why Bilstein includes uniball camber plates for the front struts. In combination with the camber plates, the rebound and compression adjustments make it a lot easier to set the car up for the respective track, weather conditions, tire characteristics, vehicle weight, and most importantly, driver preference.
All Clubsport kits are tested and tuned on the Nürburgring for its specific appli-cation. – Regis Finn
Bilstein’s Clubsport coilover kit for our E46 M3 includes 571 pound springs for the fronts and 800-pound progressive rate springs for the rear. Being a 60 mm inside diameter spring, changing spring rates to improve the suspension setup is really easy, as 60-mm inside diameter springs are used on most coilover suspension kits.
The kit also includes monoball rear shock mounts for smooth articulation throughout the system. We also like the fact that Bilstein tests and tunes the Clubsport suspension kits for each particular application. To add to the quality of their product, Bilstein coats the shock bodies in a special three-layer, zinc-based coating that protects from corrosion and mechanical wear.
For those of you that haven’t installed a set of coilovers on a vehicle, it’s pretty straight forward. With the right tools and some common sense, it’s not bad at all. We have a shop with a lift and a few full tool boxes, which made the installation a lot easier. For the average do-it-yourselfer that works on projects at home, a jack and jack stands, a ratchet, a few sockets, and a measuring tape will be all you’ll need. You’ll also need a breaker bar or an impact gun for getting the wheels off.
Before we even touched a nut or bolt, we measured the ride height of the car. With the height measurements noted, we broke the strut tower nuts and rear shock nuts loose before getting the car in the air. Breaking the nuts loose before getting the car in the air helped out because the shocks weren’t at full droop causing any downward pressure on the nuts. Once that was done, we pulled the wheels off and did a quick inspection of the wheel wells to make sure that there were no damaged components.
With a clean bill of health, we got started on removing the old suspension. The old suspension was really easy to pull out of the car and took us very little time. The only problem the old suspension gave us was the rear springs. It took some prying on the control arm to get the spring out of its seat. With the old suspension out, we tied bungee cords around the control arms to hold them up so they wouldn’t droop too much and damage the brake line.
We started our installation at the right front corner. Slipping the bottom of the coilover into the spindle, we tightened the bolt to hold it in place and lifted it up to the strut tower. Once the studs came through to the engine bay, we tightened the nuts that secure the coilover in place. To button up the first corner, we bolted the sway bar end link to the coilover, made sure no lines were pinched or twisted, and moved on to the right rear.
The rear suspension components use a separate spring and shock, not a true coilover like the fronts, so we put a little pressure on the control arm to get the spring and its collar into the seat on the control arm. After it was in place, we secured the shock in its location and looked over the area to make sure everything was in its place. We started on the driver’s side and everything went in with no problems, just like the passenger side. “This was the easiest, most straight-forward coilover install I’ve ever done,” stated our shop tech, Kyle Kitchen.
After all was said and done, we slapped the wheels back on, lowered the car to check the ride height, and set the compression and rebound. “A good starting point would be to set both compression and rebound at 5, and adjust from there,” added Finn.
Surprisingly, the height that the system was set to from the factory was almost perfect for us. We only had to lower the rear an 1/8th of an inch for it to sit how we wanted. With the height set, we put the car back on the lift and put our vehicle scales under each tire to see how balanced the car’s weight distribution was. We didn’t need to corner-balance the car because the weight was close to being evenly distributed throughout all four corners.
Now that the install is complete, the only thing needed to bring the system to fruition was an alignment. We headed over to one of our local, trusted alignment shops and had them set the toe and camber. They set the front camber to -2.9-degrees and the rear to -2.2-degrees. We also asked the shop to put a mark on the strut tower bar where -4-degrees would be. This helps out a great deal when we get to the track. We just have to line up the mark on our camber plate to the mark on the strut tower bar and we’re ready to race. No measuring at the track whatsoever.
So far, we really like Bilstein’s Clubsport coilover system. The installation was cake, adjustments are really easy to make, and the fit and finish is of great quality. Be sure to check back on Project M-Track3r, as we will be putting these coilovers to the test on the track. We will also be installing and putting a slew of other parts to the test on Project M-Track3r, so stay tuned!