Motovicity's Ticket To Ride FR-S Update- Energy Suspension Bushings
By Mike Kojima
A big part of making any car handle well is reducing bushing compliance. On most cars the suspension links pivot on rubber bushings. Rubber is fine for providing a smooth quiet ride, but it also allows for flex. Flex is bad for performance, because it causes deviation between where a car is steered and where the wheels are pointed. Particularly under the load of cornering, braking and acceleration forces.
Bushing flex can also cause wheel alignment to shift off spec which can cause unpredictable handling or a partial loss of grip under hard driving conditions. Under hard braking or acceleration bushing movements can also cause wheel hop.
Since we are going to be increasing the load on the FR-S' suspension Energy Suspension will be supplying the winning Ticket to Ride shop a set of their polyurethane bushings to help keep things pointed in the right direction. Polyurethane is a good compromise between soft stock rubber and zero flex spherical bearings. It is much stiffer than rubber but still allows for some compliance.
In modern cars with more complicated suspensions too much stiffness in the wrong direction can cause the suspension to bind. Energy considers this and has designed in engineered flex into some of the bushings to reduce this potential area of concern.
Urethane bushings can also squeak under long term use. Energy has designed in some features to reduce this as well. We will show you some of these features below as we give you a closer look at the full Energy Suspension kit for the Scion FR-S.
The front control arms on the FR-S see a lot of load as they handle both braking and cornering forces. The front lower control arm bushings have engineered flex toward the upper center of the bushing since they are arranged horizontally and need to flex with every movement of the suspension. The lower part of the bushing is solid to resist movement to the side and front to rear. These are the loads imposed by braking and cornering, If this bushing were completely solid, there would be a lot of bind in the front suspension, perhaps enough to damage the lower control arm! The rear bushings rotate with suspension movement so they have grease retaining grooves to hold lubrication to prevent squeaking. The bushings pivot on a yellow chromate coated steel sleeve which reduces overall bushing thickness for additional stiffness and reduces corrosion for less squeaking over the long term as well.
The bushings for the rear suspension links all have grease retention grooves and yellow chromate steel liners of various thicknesses. These bushings all pivot so it is important to give them something smooth to spin on, not just the mounting bolt like a lot of cheapo bushings do. If the bushing had no liner, the additional thickness would make for a softer bushing and nullify much of the effect of a harder material. Some other bushings require that you reuse the stock sleeves from the rubber bushings. This involves burning off the stock rubber or a lot of laborsome messy work to get the rubber off the sleeve. Getting new ones saves a lot of install time.
Energy supplies the entire rear link assembly complete with bushings for the rear swaybar. Reducing compliance here is pretty easy to feel. The center bushings are all urethane as well. They are textured and grooved internally to retain the special silicone grease shown here.