560 SL Stage 1 Suspension

In tandem with the engine modifications, we proceeded to improve the handling to match the increase in power without losing the essential goodness that make this car a Mercedes.

Choosing the correct spring rates without causing the ride to deteriorate and still giving a good “look” was a critical part of the process. To help improve roll stiffness and chassis balance, larger HB Sport anti-roll bars were installed (20% stiffer front & 50% stiffer rear). The rear bar is specially made to fit the anti-squat rear suspension design on the 560 SL. The shocks were updated to Bilstein HD units which were in keeping with the overall goal.

Additionally, all the suspension rubber was replaced including the subframe mounts. Even though this car had low miles, time takes its toll on rubber parts.

The front subframe and the suspension parts were refinished and all the hardware was re-cadmium plated to look like new. The same was done to the rear.

In the rear, we installed adjustable trailing arm bushings which allowed for camber and toe-in adjustment. The factory bushings are static so there is no adjustment on the standard set-up. It is a good thing we did this as the rear suspension had 1° too much negative camber and the rear wheels were toed out; not a good thing for stable handling! Because this project wasn’t a full-on performance build, the wheel alignment specs stayed normal.

One issue with these adjustable bushings is the problem of tightening the outer bushing bolts while the rear subframe is bolted up. The rear wheel alignment has to be done and the bolts marked so that the subframe can be dropped down for the final tightening. This is doable in the shop, but not recommended for DYI installation. This issue only applies to 107 cars, the 126 models has access available.

One important step on this car towards better handling was the installation of Euro bumpers (and head lights) which reduced the weight of the car and helped centralize the general mass. This work was done by John Borchelt at MA Carbon (https://www.macarbon.com/). Although we can do this work, the car was modified by him before we received it.

The handling and ride goals were accomplished using bolt-on parts.  Doing so allowed us to preserve the authenticity of the R107 as a luxury roadster, while unquestionably increasing the excitement and agility of the car overall.  The result was very satisfying; the SL experience with the HB Sport advantage.

To top off the improvements in the chassis, we added a 16x8” tire/wheel package. The cornering power was increased to a level that matched the chassis dynamics while keeping the classic look of the 560 SL.