2013 Scion FR-S: Hanchey Vehicle Technologies Camber Plates
July 4, 2013
Zero degrees of camber. That's the factory spec on our long-term 2013 Scion FR-S. And being that its front end is underpinned by MacPherson struts, we see fruit, and it is hanging low. This is because in roll, struts inherently tend to gain positive camber more quickly than do, say, double wishbones. To offset this effect and to "stand the tire up" more in hard cornering, you want to increase the suspension's static negative camber.
No problem, I'll just crawl underneath and dial in some more negative camber by adjusting the FR-S's factory eccentric bol- [record screeeetches]- not so fast, there, zippy. Toyota/Subaru, for reasons that will baffle mankind for eternity, decided not to include provisions for adjusting camber on their rear-drive sports car that will likely become one of the most common sights at track days and autocrosses for years to come.
Generally speaking, coilovers are part and parcel with camber plates. As this is a dual-purpose car, and we're not running ultra-sticky tires like Hoosiers or even DOT R-compounds on the track, adding a bunch of roll stiffness with the higher spring rates of coilovers makes little sense. And while coilovers allow you to lower the ride height, the trade-off in terms of suspension travel, bump steer and nose scrapeage aren't worth the small reduction in center of gravity height.
On real-world roads, suspension travel is your friend, and so are stock ride height and reasonable spring and damper rates. Blast down one bumpy canyon road in Project FR-S and you, too, will appreciate how well it soaks up these road insults without upsetting the chassis or kicking the steering wheel out of your hands.
So what to do? Enter Hanchey Vehicle Technologies (HVT). Their camber plates for the Scion FR-S were designed to accommodate the stock struts (they can also be used with coilovers if you so choose). Traditional camber plates are flat. These are not, as the camber plates poke through the hole in the top of the strut tower. This design accommodates the tall stack height of the stock strut and new upper spring perch so that ride height is not affected. Were you to simply use flat plates instead, you'd end up with a jacked-up, 4x4-style ride height. The HVT camber plates do not affect ride height at all. Perfect!
There's only so much room to tilt the top of the stock struts inward due to the large diameter of the spring. Basically, at some point, it hits the chassis. This means you won't be dialing in, say, -3 degrees of camber if you're retaining the stock struts, which is fine because if your tires can actually make use of that much negative camber you probably need way more roll stiffness than the stock struts provide anyway. We were able to get a max of -2.0 degrees camber with the HVT camber plates.
Notice that the slots in the HVT camber plates tilt not only inward, but slightly back as well. The slight rearward angle means that as you dial in more negative camber with the HVT camber plates, they also gain caster. This is a good thing. In low-speed corners when you have a lot of steering angle cranked in, the increased caster effectively increases negative camber further.
Installation is easy. The stock struts pop out of the car in minutes. Then it's a simple matter of borrowing a spring compressor from your local FLAPs, making sure they didn't screw you over by forgetting to include half of it inside its case (not that this happened to me during install. No way would that happen. I mean, how could it?), popping off the old upper strut mounts, swapping in the HVT assemblies and aligning the car.
The HVT camber plates use a huge spherical bearing at the top to handle axial loads, whereas that little flat ring in the upper right corner in the photo above is a Torrington bearing to manage the radial steering loads. That shiny finish you see elsewhere is nickel plating. This is a very hard coating that is highly abrasion-resistant. It also looks pimpin'.
So to summarize, in addition to increased negative camber, we now also have increased caster and less squishy rubber, all with no impact on ride height/suspension travel. Maybe we should thank Toyota/Subaru for not putting factory camber adjustment on these cars after all...
Jason Kavanagh, Engineering Editor
Source: Hanchey Vehicle Technologies