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You can see how the Whiteline roll center correction kit drops the outer control arm pivot point downward to keep a closer to stock roll center and camber curve even when the car is lowered. You can also see how the bump steer correction kit lowers the outer tie rod by the same amount to keep bump steer in check.
At this time we replaced the upper strut mount bolt at the spindle with these Whiteline cammed camber adjusting bolts. This will work with the KW slotted lower strut housing so we can adjust kingpin inclination angle at the top using the camber plate and camber at the bottom using these bolts with the eccentric. This way we can have equal scrub radius and self aligning torque from right to left sides.
The stock steering rack bushings are really soft rubber and allow the rack to move back and forth over a 1/4″ under load. On our car we replaced these with solid aluminum bushings but we want the SEMA car to have some refinement so we used these Whiteline urethane bushings which are much stiffer than stock but can still absorb some noise and vibration.
The Whiteline bushing easily replace the stock rubber bits. Unlike most cars, the FR-S has electric power steering so the rack is really easy to remove, no hydraulic lines and mess involved. On our car getting rid of the squishy rubber made a big difference.
On the rear of the car, we replaced the stock lower arm bushings with these much firmer Whiteline parts. For our own project car we used all spherical bearings for the ultimate in accuracy but for the SEMA car we will use Whiteline urethane bushings for more refinement and less road noise. The Whiteline parts have a steel backing for positive press fit and retention and a large inner sleeve for less compliance. Since multilink arms have to move in three degrees of freedom, the Whiteline parts have some engineered flex in them to avoid binding, a problem in solid urethane bushings. That is what the holes are for.
Another cool feature of the Whiteline bushings is the pocketed interior of the bushing. These pockets act like reservoirs for grease to reduce sticking friction which can hurt the ride and suspension function. If you look real close, you can see the molded in lip seals to keep the grease in place. No other urethane bushing has this innovative feature which will keep a Whiteline bushing spinning smooth and squeak free for a long time.
