Cusco Adjustable Rear Lower Control Arms - WRX, BRZ, FR-S & 86
Your rear lower control arms locate the wheel laterally, and on a factory car they do that through rubber bushings. Rubber deflects under load, which means every time you load the rear in a corner, the wheel moves slightly from where it should be. These Cusco arms replace that compliance with adjustable pillowball ends, so the rear stays where you put it.
What Deflection Costs You
Worth understanding, because it explains a feeling most people can't quite name.
Factory bushings are soft on purpose. Subaru and Toyota both want a car that's quiet and comfortable, and rubber absorbs road noise and vibration well. The tradeoff is that soft bushings let the arm move under load, and when the arm moves, your rear wheel alignment changes with it.
What you feel is a rear end that goes slightly vague when you push it, or one that behaves differently depending on how hard you're loading it. The car isn't doing anything wrong, it's just that the geometry you set on the alignment rack isn't the geometry you have mid-corner.
Pillowball ends barely deflect at all. The arm holds its position, the wheel stays located, and the rear end responds consistently whether you're driving gently or leaning on it hard.
Grip Makes It Matter More
This is why these show up on built cars rather than stock ones.
The higher your grip level, the more load goes through those bushings and the more they deflect. A car on factory tires never generates enough cornering force for it to be a big issue. Put on sticky tires or anything wider than stock and you're loading the suspension considerably harder, which means more movement and more benefit from removing it.
Same logic applies to track use, autocross, or anything where you're actually at the limit rather than near it.
Adjustable, So You Can Set It Properly
Beyond eliminating deflection, these are adjustable, which turns them into a tuning tool rather than just a stiffer replacement part.
That matters most on a lowered car. Dropping the ride height changes your rear geometry whether you wanted it to or not, and adjustable arms let you correct that rather than accepting whatever the drop gave you. If you're running coilovers or lowering springs, this is how you get the alignment you actually want instead of the one the car happens to have.
Expect Some NVH
Being honest, since it's the tradeoff.
Rubber bushings absorb noise and vibration, and pillowball ends don't. You'll notice more road noise and more feedback coming through the rear of the car, particularly over rough pavement. That's not a defect, it's what you're accepting in exchange for the geometry staying put.
Most people who fit these consider it a fair trade and stop noticing within a week. But if your priority is a quiet, isolated ride, this isn't the modification for you.
Book An Alignment
Non-negotiable. You're replacing suspension arms and these are adjustable, so the car needs to be set up properly afterward. Budget for it as part of the job.
Worth going to a shop that understands performance alignment rather than a chain that'll just set it to factory spec, since the whole point of adjustable arms is getting settings you actually chose.
Fitment
2015-2021 Subaru WRX
2013-2021 Subaru BRZ
2013-2016 Scion FR-S
2017-2021 Toyota 86
2022-2026 Subaru BRZ
2022-2026 Toyota GR86
Sold as a set. Rear position.
Who Should Run These
This is for the owner running real tires who's noticed the rear go vague when they push, and for anyone who's lowered the car and wants the geometry corrected rather than approximate. Track days, autocross, or a fast road car where consistency matters. Get them in, get a proper alignment, and stop losing your setup every time you load the car up.
Fits: 2015-2021 Subaru WRX, 2013-2021 Subaru BRZ, 2013-2016 Scion FR-S, 2017-2021 Toyota 86, 2022-2026 Subaru BRZ and Toyota GR86. Type: adjustable rear lower control arms with pillowball ends. Sold as: set. Required: alignment after installation.
