BILSTEIN Internal Bypass Technology

Inside BILSTEIN Motorsports internal bypass shocks.

External bypass shocks have been a commonplace sight among off-road racecars and high-end aftermarket rigs for decades. Shocks like the BILSTEIN M9200 (Bypass) provide position sensitive damping throughout the stroke. With different zones of damping, the user can fine-tune the damping for different off-road or track conditions.

Internal bypass shocks are like a wolf in sheep’s clothing – they don’t announce themselves with external tubes and adjusters that prevent the addition of a threaded body and coil spring. Internal bypass shocks are becoming more common in the suspension aftermarket and BILSTEIN engineers are on the edge of that development.

“With our success in early 2020, BILSTEIN is one of hottest brands in the industry,” announced renowned motorsports engineer Kevin Rumley.

“The internal bypass groove allows the vehicle to have 2 unique dampening coefficients relative to predetermined suspension positions. We can use this strategy to force the suspension in to a position that improves body aerodynamic attributes such as downforce and side-force. Once our vehicles body has achieved this aero-platform we allow the suspension to move again to optimize mechanical grip,” Rumley explained.

Case-in-point; if you allow shock oil to bypass the working piston at the top of the rebound stroke you can get better weight transfer to raise your wing up into clean air. BILSTEIN achieves this functionality by machining grooves on the inside diameter of the shock body, allowing oil to bypass the main working piston at specific areas of the stroke. This feature can be added to any 46mm BILSTEIN motorsport shock upon request.

Who can benefit from this technology? “Any organizations that have body ground height rules would benefit from this technology. It’s kind of like having your cake and eating it too,” Rumley concluded. For more information on BILSTEIN internal bypass shocks or machining services contact [email protected].