Straight from AST…
The following video is the raw footage of video we’ll be showing at our booth for Performance Racing Industry tradeshow (in Orlando December 6-8). We’ll clean it up a bit.
This is the AST 4200 double adjustable damper on the shock dyno. The 4200 is based on AST’s Twin Piston Dual Adjust (TPDA) technology. Simply put, TPDA moves the external reservoir into the base of the shock. The lower piston you see acts as the bleeder valve that a normal external res shock would have at the top of the reservoir. This controls the pressure put on the floating piston. With the valve open, the floating piston does its job and moves up and down as the shock runs through its stroke. The compression piston is stationary with relation to the body of the shock. As you change the adjustment for compression, the pressure increases in the main body of the shock and creates more compression damping.
This particular shock is using the red synthetic oil designed for viscosity stability in endurance racing. Plus it shows off really well for the video. We can build or rebuild shocks with this fluid for special applications. This technology is proven and has been used over the years.
We have the AST 4200s in stock for BMW E36. Applications for E46 and other models can be specially ordered at this time; We will begin to stock as many models as possible. Of course “eye to eye” style shocks are easily done (see pictures below). E30 front 4200 doubles always present a challenge since we need the uprights to build them. Anything is possible, though.
Brian