The Ultimate EVO Suspension, Project EVO IX Part 3

,

So are dampers that cost nearly ¼ of the price of the car worth it? If you are just interested in high performance street driving we think no. Moton makes a much lower cost Clubsport damper for you. If you are actually going to the track and compete then these highly adjustable dampers might make the difference between winning and losing. The Motorsport dampers are 3-way adjustable independently for high and low speed compression damping and rebound damping. High speed compression affects how the car will react when hitting big abrupt bumps. You can adjust the high speed damping to keep the car from crashing through the travel and bottoming out hard when you hit an FIA curb while still providing a compliant ride.

The low speed damping circuit mostly affects body roll and pitch as does the rebound control. With the ability to adjust low, high speed and rebound damping independently, it is possible to have a car that can meet all of these seemingly diametrically opposite goals, taking on big hits, resisting roll, squat and dive and riding relatively smoothly. Contrary to popular belief, race cars need to ride as smoothly as practical to reduce tire shock. Tire shock is any sort of hopping or skipping that upsets the tire’s contact patch. For a tire to give its best grip, it has to be planted solidly on the ground. A car that bobs, rolls excessively or hops is losing grip. With the Sophisticated damping control that the Motons offer, it is possible to get away with a softer spring for less tire shock and a decent street ride to boot. Conversely, a high spring rate for the street can still ride well due to the Moton’s precise control.

Motons have a high precision valve system so that each click of the adjusters changes the damping force by an equal amount. Hardly any shocks can do this and common street adjustable coilovers are not even close to having consistent changes for each click. Most shocks adjust damping force by changing the preload on a stack of valve washers. Motons change the diameter of precisely machined metering orifices when you turn the knob. Motons also have a large diameter shaft which displaces a lot of fluid as the shaft is pushed into the shock body. More shaft displacement means more fluid flow though the valves. The large volume of fluid makes the shocks valving all the more sensitive, even at low shaft speeds.

Motons also have adjustable gas pressure. There is a schrader valve in the shock’s remote reservoir where the nitrogen gas pressure can be adjusted. The nitrogen is kept separate from the fluid in the remote by a floating piston. Gas pressure works like spring preload. It changes the force needed to move the suspension initially but does not affect the spring rate. It is possible to raise the gas pressure for a more responsive suspension for the track and to reduce it for a softer street ride. The Moton strut bodies also have an adjustment for camber built into the lower mounts. This enables us to adjust both the caster and the steering axis inclination angle.

Here is the Ground Control camber/caster plate. It sits on top of the shock tower instead of underneath it like most plates to preserve wheel travel. It integrates with the Works strut tower brace.

To attach the Motons to the front of our car’s chassis we used a Ground Control camber caster plate. We feel that the Ground Control unit is superior to any currently on the market for several reasons. The first is that it allows a generous amount of caster adjustment. We feel that the EVO needs more positive caster. Positive caster improves straight line stability and the EVO has such telepathic steering that it can be twitchy when driving on the freeway. Adding caster can improve this. Positive caster also increases negative camber when the wheel is turned which helps front grip making the addition of positive caster a win win situation. The GC plates bolt on top of the strut tower so they allow the car to be set lower while maintaining wheel travel. Insufficient wheel travel is a common handling problem with radically lowered cars. Finally the GC plates incorporate an ingenious system to reduce the load on the spherical bearing the shock shaft rides on. The upper spring seat has a ball and socket surface with a roller thrust bearing underneath it. The ball and socket allows the suspension to articulate smoothly through its travel as the wheels are turned while the thrust bearing supports the weight of the car. This allows the GC plate to last a long time without maintenance.

Leave a Reply

Your email address will not be published. Required fields are marked *

*
*