In preparation of some racing in 2019,
and I have been developing a custom damper kit for the S1 Evora. There's really not anything available in in the aftermarket that meets are needs, especially in the US. Basic requirements are:
- Large piston area, variety of piston profiles available (digressive and linear)
- Appropriate valving available for use with OE springs
- User re-buildable
Nice to have items would be:
- Ability to mount inverted
- Low cost.
We are sort of lucky that the OE Evora shock is not too complicated. It mounts with standard rod ends, is reasonable length, and uses a 2.5" ID spring. After looking at a bunch of different options from the usual suspects (Koni, Penske, Ohlins, MCS, JRi, etc) we decided to build something using the Bilstein motorsports catalog. Everybody knows plenty about the OEM parts thats Lotus uses on many cars, but I suspect few have experience with the Bilstein motorsports offerings.
First lets start with the parts that came off the car:
We modeled these up against an appropriate length part from an aluminum racing shock from Bilstein.
Notice that we had to build some lower perches and extend the rod ends. This is because we wanted to invert the shock to reduce unsprung weight. The shock body itself is threaded and a user could convert these to a height adjustable coilover with the trivial installation of an adjustable perch. Here some partially assembled photos.
After more assembly.
When valved like stock, the ride for these units is fantastic. The new 2-way adjustable rod is way, way beyond what was offered on the PSS9/PSS10s in the past. Adjustable authority is amazing. On the dyno they look like art. Best of all, like almost everything from bilstein motorsport, they are priced really aggressively -- around $400-500 per corner.
Anyway, hope you enjoyed reading. Nope. Not for sale.