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The changes we have made to our car’s chassis so far are pretty amazing. With the Whiteline sway bars, our car corners much better, flatter and with much less overshoot. Our FR-S now has faster response to steering input, way less understeer and way less sudden oversteer. The car is much easier to slide predictably now and you can get on the throttle a lot sooner during corner exit.
It is very interesting to note that even though we have installed Whiteline bushings in our transmission mount and subframe mounts, there is no perceptible gain in vibration or noise due to the bushings. Our shifting is more positive and we feel that the subframe bushings are a big contributor to the improved predictability that our car has while cornering.
The Cusco braces make a pretty large difference in the chassis stiffness, most of which manifested itself in improved ride comfort. We were surprised the the decently stiff FR-S/BR-Z chassis would respond to additional bracing in such a feelable way. Even though our car is a lot stiffer and more responsive, the amazing thing is that it rides smoother than the stock car did.
With the bigger Achilles 123S tires, we had a lot of grip. We think that the car doesn’t like stagger fitment because staggering the tire widths made the car pick up some understeer, especially in slower turns. We didn’t attempt to tune the understeer out of the car with chassis adjustment and instead we will go to a square setup later.
The 123S tires have tons of grip and are very predictable, perhaps they may be a consideration for ST class autocross and street class time attack in addition to drifting. The one thing we didn’t like about the tires is that the thick tread with deep grooves had a lot of tread squirm which made the tire feel imprecise and lazy as if it was running a lot of slip angle.
We believe that this can be cured by shaving the tires and this would make the 123S a super fast track and autocross tire. It has the grip, this should give it the feel. We think the 123S might just give the current grip king the Hankook RS3, a run for its money.
Another note is that these were early production tires and we heard that later tires will have a thinner tread to reduce the squirm.
Our chassis mods have complemented the big boost in power that our supercharger has given. We still have way more chassis and brakes than engine! Stay tuned, we have more suspension magic and more power mods coming soon!
Sources
Whiteline Suspension
Cusco USA
Mackin Industries
Achilles Tires
Innovate Motorsports
Koyo Cooling Systems
K&N Filters
Motul
KW Suspension
Race Comp Engineering
Nameless Performance
Greddy
Berk Technology
Technosquare
Norwalk Toyota/Scion
Scion
Want more Project FR-S? MotoIQ Project Scion FR-S
2 comments
I’m curious to hear your logic for going with the 18″ wheels instead of 17″. The 18’s definitely look better but I know looks alone aren’t enough for MotoIQ.
To fit over the brakes.