Best Suspension Mods for Scion FR-S & Subaru BRZ [ZN6/ZC6]

The FR-S is a car designed and focused around handling prowess, but the cost effective nature of its construction leaves it with a few imperfections that keep its handling from being as good as it can possibly be. I know it can be hard to hear and get past the hype, but stick with us here and you’ll turn your ZN6 or ZC6 from a dull butter knife to a razor sharp scalpel when it comes to cutting apexes.

In this article we’ll be addressing the shortcomings of the stock FR-S Suspension/BRZ suspension – and how to fix them.

Before we go any further, let’s get this one out of the way.

Tires. Unless you plan on going drifting, the stock tires of your FR-S or BRZ will let you down every time. See, in the interest of making it easy to drift even with a relatively low output engine (that and the fact that they’re CHEAP), Scion and Subaru spec’d out your Toyobaru as stock with low rolling resistance PRIUS TIRES. YOUR FR-S OR BRZ HAS PRIUS TIRES.

Let that sink in.

THIS IS A BIG PROBLEM. UNTIL YOU UPGRADE YOUR TIRES, HANDLING CANNOT IMPROVE. Well, maybe that’s a bit of an exaggeration, but tires are such a critical part of handling performance that without upgrading those, your handling can’t improve much anyway. Protip: if you DO plan to go drifting, don’t try to be Ryan Tuerck right out of the gate, because you’re not him and you’ll quickly be another parts car on the forums and a youtube video we laugh at. Do us all a favor and get familiar with the car at an event like Drift Day or something first, before heading out there to get slideways.

We’re getting off topic here so we’ll get back onto the topic of tires and handling performance. So as we were saying, You can only stick to the road as well as your tires will let you, so tires are the “crust” of your handling performance pizza. FR-S/BRZ Specialist Charles runs Toyo Tires R1R tires on his E85-fueled, legitimately Electric-Supercharged Scion FR-S (we’ll get into the craziness that is the FUNCTIONAL electric supercharger in another post – pic to satisfy SR20 rule “pics or it didn’t happen”).

At ModBargains & ModAuto, we’re major stocking distributors for Toyo Tires, Hankook, Nitto, Michelin and other performance tires, so we often have tires available and on hand right here at the shop. All of these will offer a major increase in grip over the stock tires, translating to faster lap times around the circuit, quicker 1/4 mile times and better hook-up off the line.

Then there’s the wheels. The stock FR-S wheels and BRZ Wheels aren’t the lightest thing in the world, so a lightweight set of aftermarket wheels for FR-S will enhance the handling performance of your car.

Why is this? Well, most of you are probably familiar with the concept of weight reduction  – it takes less effort to move a lighter object than a heavy one, right? Now we’re gonna throw some physics at you – the wheels spin, right?
(note:  We’re just approximating here for the purpose of explaining the concept in the simplest terms we can here, so any Physics majors out there will have to forgive any errors here, but we think we’ve covered the basic idea.)

There’s a thing called centrifugal force at work here – the same invisible force that wanted to pull you off the spinning merry go round on the playground as a kid. We’ve established that if we reduce the weight of the wheels, the car will be faster, right? Most OEM wheels are 20-21lb, whereas a performance wheel can be 13-20lbs, depending on how wide it is, style, material and how it was made (cast vs forged etc). So let’s assume the stock wheels are 20lbs, and you buy some aftermarket wheels that weigh 18lbs. On the face of it, it looks like you only saved 2lb per wheel for a total of 8lb – but you’d be wrong. See, as the wheels spin, they act as if they are heavier, and as the wheel spins it becomes approximately 4x heavier than it was standing still thanks to Centrifugal force. So if you have a 18lb wheel, and multiply that by 4 it comes out to 72lb per wheel – the stock ones were 80. So now we’re saving 8lb per wheel, slicing 32lb total off the car effectively instead of just 8.

The other thing to think about with wheels that enhances handling is that wheels are “unsprung weight”, which google defines as “In a ground vehicle with a suspension, the unsprung weight (or the unsprung mass) is the mass of the suspension, wheels or tracks (as applicable), and other components directly connected to them, rather than supported by the suspension.” Which means the suspension doesn’t have to work as hard, also contributing to better handling.

Forgestar’s Flow Form 5×100 wheels are a great looking lightweight wheel option that can stand up to the abuse of track days and still look great on show day.

One of the biggest things that takes away from your FR-S/BRZ handling performance is one of the smaller bits of the car- the bushings in the suspension and chassis.

There’s a lot of bushings, and in the interest of ride comfort and keeping costs down, the OEM bushings tend to be overly soft and allow a lot of “deflection”, which is when the suspension geometry moves in a way it’s not supposed to, leading to sloppier handling response.

This simple graphic by Ultra Racing illustrates the principle of suspension deflection pretty clearly, so we’ve posted it here to give you a better idea of what suspension deflection is.

So we’ve established the OEM bushings are too soft. What should you change them out for? Conveniently, Whiteline Suspension offers nearly all of the bushings you might need, and are one of the most well-reputed names in suspension – put simply in not-so-PC terms, Whiteline’s crew of suspension geometry boffins in Australia doesn’t #%*( around when it comes to suspension. It’s top shelf stuff, and several of us here run Whiteline products on our own cars.

Now let’s get into some of these bushings and what they do. Check out the description for each – how many of the symptoms described are present in the way your “86” handles?

Whiteline Suspension Gearbox Shift Bushing for 2012+ Scion FR-S/Subaru BRZ [ZN6/ZC6]

If you’ve ever noticed difficulty while shifting or excessive shifter movement under acceleration, then you likely need Whiteline’s Positive Shift Kit bushing.  This bushing fills the void present in the stock bushing, which causes the OEM bushing to allows lots of play/movement.  This bushing will increase NVH (noise, vibration and harshness) by a small amount since the movement in the stock transmission will be reduced.  FR-S Specialist Charles runs this bushing on his own personal car to sharpen up the feel.

FRS/BRZ Diff Support and Outrigger Bushing

When you put the pedal down and get on the throttle in the Scion FR-S and Subaru BRZ, there is sometimes a feeling of “lag” and a “jerk” from the chassis.  This is caused from the differential loading up with torque forces and then unloading that torque.  When this occurs, you’ll usually experience a pulsing feeling inside the car.  This can be uncomfortable, makes you look like a “noob” driver and worst of all, prevents all of what little power the car makes stock from reaching the ground – the car needs every pony it can get at the wheels, and this bushing is the cowboy ensuring those horsies don’t get lost along the way. Whiteline has solved this problem by developing these bushings for the rear differential.  These help keep the differential from twisting around and creating a jerky ride.  In simplest terms, These bushings help you put power to the ground when you get on the gas and helps provide for a more direct feel with the drivetrain.  FR-S/BRZ Specialist Charles uses the Whiteline Diff Support and Outrigger Bushing.

Whiteline Suspension FRS/BRZ Rear Diff Support Bushing

If you’ve ever felt slop in the factory chassis when applying the throttle, it could be the differential twisting in the bushings from the force of the engine that’s making the chassis sloppier than a hooker two weeks from retirement.  To help prevent this and tighten things up, replace the factory bushings with Whiteline Suspension’s rear diff support bushings, which will help decrease the time it takes for power to get to the back wheels, improve engine feel and restricts undesireable driveline movement.

Beyond the bushings though, there are other issues to address – like the less-than-precise feel the steering rack sometimes has.

The Fix for Steering Rack Sloppiness 

There are a wide variety of options available depending on your budget, style, taste, brand preference and how much underhood clearance you actually need. Cusco offers a fine set of Front & Rear Strut Tower Braces for Scion FR-S/Subaru BRZ [ZC6/ZN6] that are the classic 2-point style, tying the tops of the suspension together preventing suspension deflection under load.

Whiteline Suspension FRS/BRZ Rear Sway Bar Mount Brace

After adding coilovers, swaybars and bushings, the stock swaybar mount can flex and EVEN BREAK under extreme cornering forces.  The Whiteline Sway Bar Support reinforces the factory mount, and ensures the sway bar stays where its supposed to without deflection.

There are several types of Strut Tower Braces available for the FR-S/BRZ, but the Radium Auto Adjustable Strut Tower Brace is one of our favorites.
The Radium Front Strut Tower Brace offers several key advantages over competing strut tower braces. This kit features 6-point mounts that utilize all 6 strut bolts, a raised design that allows clearance for aftermarket upgrades, works perfectly with OEM diagonal braces and features adjustable preload for a comprehensive product designed for the discerning enthusiast.

Alternately, if you’re not able to go the “over-the-manifold” route with your bracing, RaceSeng Stiff Arm Front Strut Bars for FR-S/BRZ are a popular option.

Bracing for Better Braking

Wait, what? This next brace is one you’d never think of, and scarily enough, this one is robbing you of a TON of braking force. Alarmingly, the ZN6/ZC6’s firewall is so flexible that when you brake hard, the firewall MOVES and thus the force you’re putting on the pedal isn’t being applied to the brake master cylinder – the thingy that sends the force of you pushing the pedal out to all four brakes – and so you’re losing a LOT of braking power. Don’t believe us? See for yourself in this short video below.

Amazingly, a simple $74.99 part by Radium Auto resolves the problem – the Radium Auto Brake Master Cylinder Brace for 2012+ Scion FR-S/Subaru BRZ [ZN6/ZC6].

Camber Bolts & Caster Plates

When you decide to lower your Scion FR-S / Subaru BRZ the front wheels will have negative camber, or be tilted inwards.  This problem creates uneven tire wear and less grip when corning hard.  Hotchkis have developed these Hotchkis Sport Suspension Camber Plates to solve this very problem.  These Hotchkis Camber Plates enable you to adjust your camber to set it closer to 0 in order for the best handling possible, but we also offer Vorschlag Camber Caster Plates for FR-S.

Dial in Just How Much Oversteer or Understeer you want with a Sway Bar Upgrade

Replacing the OEM sway bars with a set of performance sway bars can have a huge effect on the handling character of your car, altering where the limits are and what the car will do when you reach them.

The sway bars are effectively a spring that ties together the two sides of the suspension to keep things working together in harmony. Sway Bars for the FR-S/BRZ are available from Cusco, Eibach, Hotchkis and Whiteline – all of which are fine choices and will all improve handling, and most are adjustable so you can tailor your handling characteristics to your specific driving style.

Stay Aligned once you Go Low with Adjustable Rear Toe Arms + Lower control arms
 
The FR-S/BRZ doesn’t have rear adjustable camber as factory equipment, and usually once you lower your FR-S/BRZ, you’ll need camber and toe adjustments beyond what the factory arms permit to get a proper 4-wheel alignment, so the bottom rear lower control arm needs to be replaced with one that is length adjustable to ensure your alignment stays correct by adding the adjustment. Often, the shop tasked with aligning a lowered FR-S can’t do it fully because the stock toe arms have run out of adjustment. These adjustable suspension components are Safe/cheap protection to prevent that scenario.

The lower control arms allow camber adjustment, which is otherwise impossible with stock parts.  FR-S/BRZ gains negative camber as suspension compresses/car is lowered. For reference, Charles’ FR-S is lowered 1.25″, and the rear camber is -2.5, and Charles does not yet have aftermarket rear LCA’s. Toe is set to ZERO with factory pieces.  However, they may be needed for your application to keep alignment specs within range when lowered.

Toe arms from factory may or may not have enough adjustment to get rear toe within specs…SPC toe arms allow significantly more adjustment than stock.

SPC Performance offers Adjustable Rear Lower Control Arms and SPC Adjustable Rear Toe Arms, but we also offer Cusco Adjustable Rear Lateral Arms (LCAs). The SPC is cheapest option, but has been updated to be similar to OEM, but is adjustable.

The above mods to your chassis and suspension itself will dramatically sharpen the handling of your FR-S/BRZ, but of course, there’s one more way to increase grip and handling performance that we haven’t yet mentioned.

GRIP THE WIND – Functional Aerodynamic Devices

Aerodynamics. Downforce. Yes, while the majority of front lips, splitters, diffusers and rear spoilers on the aftermarket for street cars are strictly aesthetic pieces, there are a handful of aerodynamically functional parts available for the ZN6/ZC6 to squeeze every last bit of handling potential out of the car. One of a few such pieces is the APR Performance Carbon Fiber Front Splitter for Scion FR-S/Subaru BRZ,

 

 

And of course, no discussion of aero is complete without talking about the daddy of all aero devices – the rear spoiler. Though really ridiculous on a street car, giant bigass spoilers like APR Performance GT250 Adjustable Rear Wing Spoiler for FR-S/BRZ and Seibon Carbon’s AG Style Rear Spoiler for FR-S/BRZ are basically the only ones that will actually be aerodynamically useful, and may help you shave a few tenths over a longer circuit.

Thanks for sticking with us for this rather long article but we hope this has given you some ideas for how you can sharpen the handling of your own FR-S or BRZ, and enjoy every winding road that much more.

Have questions about your Scion FR-S Suspension or Subaru BRZ Suspension? Not sure what the best handling upgrade option might be for your particular goals? Never fear – that’s exactly why our team of Mod Experts are here to assist you with our Experience, Expertise and Enthusiasm and guide you to the parts that will take your build to the next level. Give us a call at 714-582-3330, chat live on ModBargains.com or stop by the ModAuto showroom in La Habra, CA any day Monday thru Saturday during business hours.

Thanks for joining us, we’ll see you next time!

Story by Nick Gregson in Collaboration with Charles Pages
Original Photos by Nick Gregson & Charles Pages