Motion Control Suspension

Submitted by Editor on October 12, 2011 – 8:27 pmNo Comment

Rennsport Systems is a distributor and a service center for Motion Control Suspension Components.

Rennsport Systems offers both double-adjustable & triple-adjustable suspension upgrade packages for 911- 964 – 993 – 996 – 997- GT-3/GT-2 Porsche cars.

A popular misconception is that horsepower makes for quicker lap times and this is singularly untrue. Quick lap times come from gains in corner exit and corner entry speeds. One of the biggest factors here is having a suspension that inspires the confidence for you to drive at speeds you are comfortable with. The real benefit of a Motion Control equipped car is that all of the components; springs, shocks, and bars work in harmony with each other controlling load transfer and dynamic weight distribution.

The objective is all about making the car easier to drive without frightening the driver and keeping the tires in contact with the road for maximum grip.

A Word about Motion Control Suspensions

Motion Control Suspension was founded in 2011 by Jerome Van Gool, one of the founders of JRZ, and former principal of Moton Suspension Technology.

Most modern race cars rely on ground effects or downforce to generate higher cornering speeds, and the suspension uses very little travel to keep aero changes to a minimum. The unique design of the Motion Control damper uses a 22mm piston rod to provide maximum fluid displacement at small suspension travels, responding to the slightest movement of the suspension.

The greater fluid displacement caused by the cross section of the 22mm piston rod combined with gas pressure in the reservoir, results in an added lifting force on each corner of the car to support the main spring without increasing spring rates. The gas pressure can be varied between 6 bar and 20 bar giving the racer an extra adjustable medium.

The 22mm piston rod compensates for less travel by increasing the diameter of the piston and thus, the displacement of fluid. Most damper manufacturers use a piston of 12mm or 14mm. Using a 22mm piston rod results in about a 300% greater fluid displacement making the damper more responsive at low damping velocities.

Fluid Displacement

	Fluid Displacement	Percentage

12mm piston	113 cubic mm	100%

14mm piston	159 cubic mm	136%

20mm piston	380 cubic mm	336%

In other damper designs, the function of gas pressure is to keep the fluid compressed and prevent cavitation. In the Motion Control damper, the gas pressure is used to give an added lifting force on each corner of the car. This lifting force offers a support to the main spring and helps carry the weight of the car so permitting softer main springs. The gas pressure can be varied between 6 bar and 20 bar. This becomes a very effective tool for pitch & squat control and stabilizing the whole platform of the car during cornering.

Gas Pressure	6 bar	8 bar	10 bar	12 bar	14 bar	16 bar	18 bar	20 bar
Lifting force per shock (lbs.)	50.7	66	83.7	101.4	116.8	134.4	150	167.5
Lifting force; 4 shocks (lbs.)	202.8	264.5	335	405.6	467.3	538	600	670

Remote Reservoir & Compression Adjustment

Compression adjuster (15-way) on cannister

The Motion Control external reservoir contains the gas volume and fluid reserve. Located on the top is the adjustable blow-off valving system and non-return valve. The blow-off valve is designed to handle the large fluid displacement caused by the 22mm piston rod and responds to the slightest movements of the rod. The blow-off valve is spring loaded with Belleville washers and by turning the adjuster, preload is forced on the blow-off valve. Increasing the preload on this blow-of valve creates higher compression damping. This can be adjusted into 14 positions. Using different sized Belleville washers varies the total adjustment range in compression.

Rebound Adjustment

The rebound adjuster is located on the top of the piston rod. Turning on the brass nut closes or opens precisely drilled orifices one-by-one below the piston. Closing off pre-measured orifices is a secure way of keeping the adjustments equal between dampers on the right & left side of the car. The rebound can be adjusted into 14 positions.

Rebound and Compression Double Valve Stack

The rebound & compression stack are non pre-loaded and built up in two phases. The primary stack consists of a main valve with a diameter of 34mm (rebound) and 36mm (compression), supported by valves decreasing in diameter according to the damper force requirements. This is the low velocity area of the damping. The secondary stack is separated from the primary stack by a small shim of 0.15mm thickness and 21mm diameter. The secondary stack limits the opening of the primary stack so by changing the composition of the valves, damping forces can be increased or decreased. The secondary stack is the mid and high speed area of the damping.

Double-Adjustable Dampers

964 Front struts

These are 14-way, double-adjustable, remote reservior shocks intended for the serious club racer and high performance street/DE enthusiast. These dampers have the same technology & precise adjustment that the full-race shocks have. These dampers are double adjustable, remote reservoir shocks with 14 separate rebound and compression controls that allow you to use a wide range of spring rates and eliminate having to revalve each time you wish to increase or decrease your spring rates. These are available in two valving ranges depending on what spring rates are going to be used.

Rennsport Systems provides each Motion Control Suspension package with a custom dual-spring setup for each person’s car and individual usage. Double-adjustable dampers are made for Porsche 944-964-993-996-997 cars, and BMW E-series.

964 Rear shocks

911 applications will be available soon.

Triple-Adjustable Dampers

These 14-way, remote reservoir, triple-adjustable dampers primarily used for competition cars. Combined with an appropriate spring package, there is not a better high performance suspension for a race car. These are available for Porsche 964-993-996-997-GT3-944, BMW E-series, and Chrysler Vipers.

Porsche 964 – 993 – 996 – 997- GT-3/GT-2 Applications

Stage I: Double-adjustable 14-way, remote-reservior dampers with custom dual spring package and adjustable swaybars

This is a set of double adjustable remote reservoir Double-Adjustable dampers and a dual (main-tender) spring package made for your specific car and application. This includes dampers, springs, separators, upper & lower perches, adjusters (rear swaybar mounts on 993′s) and lock rings. With Factory adjustable swaybars (5-way front; 3-way rear), this makes the car feel much tighter and flatter for street & track use without compromising ride quality.

Stage II: Double-adjustable, custom-valved, 14-way adjustable dampers with custom dual spring setup and adjustable swaybars

The next step up from Stage 1 package are the 14-way custom-valved, double- adjustable shocks. These remote reservoir shocks are the very best suspension components one can buy and valved specifically to your spring rates. We include a custom dual spring (main-tender) setup for your car and type of usage. This includes dampers, springs, separators, upper and lower perches, adjusters and lock rings.