We have been offering the custom build MeisterR GT1 coilovers for a while.
The result have been great for many road and track users, and even brought home 2x UK Time Attack Championship in 2017.
(Neil Wrenn in 2WD Club, and Dan Holman in Clubman+).
However, in typical MeisterR fashion, we always strive to make further improvement.
Our original concept was dive into a "Double Digressive" piston design as the high speed compression blow off will allow better better compliancy when running over curbs on track.
However, as we research and develop the new piston, we found a few unfavourable characteristic of a double digressive piston and set out to refine them.
Most double digressive on the market (Bilstein, Penske, etc) have equal face.
What that mean is the compression and rebound side is the same.
This allows you to run a very aggressive damping ratio (especially low speed), but it is difficult to achieve the peak rebound force that one would want on a good road dampers.
Lack of peak rebound force in extreme case can make a car "hop" as the sprung weight of the vehicle are not controlled until the end of the stroke.
That is how the concept of the Staggered Digressive Valve (SDP) started.
We want to achieve digressive characteristic but with vastly different compression and rebound curve.
We have experimented with many design by "staggering" the maximum flow rate on the bump and rebound side.
These are some of the piston designs we have came up with along the way.
What does the SDV achieve?
The SDV design exhibit 2 favourable characteristic:
1. The compression and rebound curve are vastly different.
The compression have high speed blow off to allow compliancy while running curb, but great low speed force to provide sharp steering response.
The rebound have good low speed damping, but very little high speed blow off.
This allow rebound to achieve high peak force value to control sprung weight earlier within it's stroke, providing more predictable control.
2. The single damping adjustment affect the compression and rebound curve differently.
The high speed compression blow off mean the damping adjustment mainly affect the low speed compression force.
The lack of a high speed rebound blow off mean the damping adjustment mainly affect the high speed rebound force.
This "staggered" combination allow adjustment of the critical rebound force while maintaining peak compression force.
The low speed compression adjustment mean steering response as well as how the suspension load the tires are directly affected by the damping adjustment.
The SDV allow us to tune the dynamic of the suspension with favourable characteristic when compare to other readily available piston design.
We will have more data in the future as we are in the final phase of testing, just want to share what MeisterR have been doing in the background lately.