With its comprehensive shock absorber and suspension programme, BILSTEIN offers the right solution for virtually any specific application. However, sometimes the requirements of the tuning and racing industry are simply too specialised to keep an off-the-shelf solution ready for every request. On these occasions, when many others would just make do with what they already have, BILSTEIN’s Department for Special Customer Requests (KSW) in Ennepetal, Germany, springs into action. Together with the US company GTWORX, a subsidiary of Racecomp Engineering, they created an extraordinary cup suspension for the Subaru WRX/STI and BRZ models. Recently launched in the US and based on the BILSTEIN B14 coilover system, it is specially designed for hobby racers, who want to drive their vehicles on and off the track. Linear springs are applied to auxiliary springs and degressive mono-tube Upside-Down shock absorbers. The latter initially react “sharply” due to their design and then soften with increasing force, in order to achieve optimum driving behaviour and adequate comfort at rest.
The partnership with GTWORX has been well-established for seven years, and, in addition to the cup suspension base, BILSTEIN also offers modified B6 shock absorbers. The suspension experts from “good old Germany” are already pretty skilled as original equipment manufacturers, replacement, race and tuning suppliers for various Subaru models, used their expertise for this particular project. However, the GTWORX specification for the customised cup suspension had some very special features: For instance, a 30 mm height-adjustable, motor-racing coilover system should have a fixed damping factor, in order to avoid overloading a hobby pilot with a massive number of adjustment options while offering an affordable price tag. In contrast with pedigree motor racing products, which are not used on public roads, the comfort component was not completely lost. The GTWORX / BILSTEIN Trophy Cup Coilovers combine all these features thanks to their clever engineering using the BILSTEIN kit as well as numerous small alterations in detail. This was also confirmed by tuning and test drives at BILSTEIN USA West in Poway, California.