The A90 Supra, a modern icon revived by Toyota in collaboration with BMW, already delivers thrilling performance straight from the factory. Its turbocharged inline-six, sharp steering, and rear‑wheel‑drive layout make it a joy on both road and track. Yet for enthusiasts seeking sharper turn‑in, more confidence at high speeds, or better utilization of the chassis, targeted handling upgrades can elevate the driving experience to another level. This article explores two foundational modifications: installing Cusco strut braces and upgrading tire sizes. We'll cover why these changes matter, how to choose the right components, and what to expect after installation.

Why Handling Improvements Matter for the A90 Supra

Factory suspension tuning must strike a balance between comfort, safety, and performance. On the A90 Supra, Toyota and Gazoo Racing already delivered a capable platform, but there is always room to sharpen the edge. Improving chassis rigidity and maximizing tire contact are two of the most effective ways to reduce understeer, improve steering feedback, and give the driver greater control during cornering or emergency maneuvers.

Enhanced handling translates to:

  • More predictable behavior at the limit
  • Reduced body roll and chassis flex
  • Better traction under acceleration and braking
  • Increased driver confidence and enjoyment

For track days, autocross, or spirited canyon drives, these modifications can reduce lap times and make the car feel more connected. Even for daily driving, improved stability and response can enhance safety.

Installing Cusco Strut Braces: Chassis Stiffness for Better Control

Strut braces (also called strut tower bars) connect the top of the front or rear suspension strut towers. Their primary job is to resist chassis flex that occurs during cornering, acceleration, and braking. The A90 Supra’s unibody structure is already stiff, but adding a well‑designed brace reduces remaining flex, especially in the front where the suspension loads are highest. Cusco, a long‑respected Japanese manufacturer, offers both front and rear strut braces specifically for the A90 chassis.

Benefits of Cusco Strut Braces

Beyond the obvious increase in stiffness, Cusco braces deliver specific performance advantages:

  • Reduced body roll – Less chassis twist means the suspension can work more effectively, keeping the tires flatter in corners.
  • Improved steering response – The front end feels more direct and connected, with less delay between steering input and tire response.
  • Better alignment retention – Chassis flex can cause camber and toe changes under load; a brace helps maintain suspension geometry.
  • Consistent feedback – The driver gets clearer signals about grip levels, allowing earlier and more precise corrections.

Installing the Cusco Front Strut Brace

The installation is a moderate DIY job for someone with basic mechanical skills. Here is a detailed process using the Cusco front strut brace (part number 622 540 A, typically).

  1. Preparation – Gather a socket set, torque wrench, 10mm and 14mm sockets, a ratchet, and extensions. A floor jack and jack stands are recommended.
  2. Access the strut towers – On the A90 Supra, the engine cover must be removed (four push‑clips) to expose the front strut tower bolts. The brace fits without major interference with the intake or engine cover.
  3. Remove the factory bolts – There are three bolts per strut tower (14mm). Loosen them gradually, but do not remove completely yet.
  4. Position the brace – Place the Cusco brace over the towers, aligning the holes. Some versions include slotted holes for adjustability; center the brace evenly.
  5. Torque the bolts – Tighten each bolt in a star pattern to 35–40 ft‑lbs (consult Cusco’s instructions). Recheck after a short drive.
  6. Reinstall engine cover – Ensure no clearance issues; the cover may need slight trimming if the brace sits high.

Tools needed: Cusco USA torque specs are typically included in the box. A torque wrench is essential to avoid over‑tightening.

Rear Strut Brace: Further Stiffness

For those who want maximum chassis rigidity, Cusco also offers a rear strut brace (part 622 540 R). This mounts behind the rear seats, connecting the rear shock towers. While the rear brace provides less dramatic improvement than the front, it reduces squat and helps the rear end feel more planted during hard acceleration or corner exit. Installation is similar but requires removing the rear trim panels. Many owners pair front and rear braces for a balanced setup.

Other Strut Brace Options

Cusco is not the only quality manufacturer. Brands like H&R, ARK Performance, and TRD offer comparable products. However, Cusco’s braces are particularly well‑engineered for the Supra, with a triangulated design in some versions that adds lateral stability. When selecting a brace, ensure it has appropriate clearance for the engine cover and does not interfere with maintenance.

Upgrading Tire Sizes: Maximizing Grip and Contact Patch

Tires are the interface between car and road – arguably the single most impactful handling modification. The A90 Supra comes from the factory with staggered wheels: 255/35R19 front and 275/35R19 rear (on the 3.0 Premium trim). While these provide good grip, upgrading to wider tires or different compounds can dramatically improve cornering speeds, braking distances, and overall control.

Benefits of Larger or Stickier Tires

  • More mechanical grip – A wider contact patch yields higher cornering force (until the tire exceeds its thermal limits).
  • Reduced understeer – Widen front tires to match rear or increase rear width for more oversteer balance.
  • Better heat management – Performance summer tires like Michelin Pilot Sport 4S or Advan A052 manage heat better than all‑season tires.
  • Improved braking – More rubber on the road shortens stopping distances.

Choosing the Right Tire Size

When upsizing on the A90 Supra, keep these critical factors in mind:

  • Wheel width – Factory wheels are 9.5″ front and 10.5″ rear. A 275 tire on a 10.5″ rim is already near maximum width. To run 285s or 295s, aftermarket wheels with proper widths (10–11″ front, 11–12″ rear) are necessary.
  • Diameter and aspect ratio – Keeping the overall diameter close to stock prevents speedometer error and interference with fenders. Common performance fits: 275/35R19 front / 295/30R19 rear, or 285/30R20 / 305/30R20 with 20″ wheels.
  • Load rating and speed rating – Ensure tires meet or exceed factory ratings (Y speed rating for 186+ mph).
  • Driving conditions – For street use, choose UHP summer tires. For track use, consider semi‑slick like Hankook Ventus RS‑4 or Nankang AR‑1.

Installation Tips for New Tires

  1. Alignment first – Before mounting new tires, have a professional alignment done to your desired specs (more negative camber up front can help wear).
  2. Mount and balance – Use a reputable tire shop with a road‑force balancer for smoother high‑speed rides.
  3. Break‑in – New tires need about 100–200 miles of gentle driving to remove mold release agents and achieve full grip.
  4. Pressure checks – Start with manufacturer recommendations (around 38 psi front, 36 psi rear cold) and adjust based on track temperatures.

Always consult resources like Tire Rack for fitment guides and user reviews specific to the Supra.

Wheel Options for Larger Tires

To accommodate wider tires, many owners swap to aftermarket wheels with lower offset (e.g., +20mm to +25mm) and wider barrels. Brands like Titan7, Rays, and Enkei offer lightweight forged wheels that save unsprung mass while allowing up to 305mm rear tires. Staggered setups with 19×10″ front and 19×11″ rear are popular for daily/track use.

Complementary Handling Upgrades

While strut braces and tires form an excellent foundation, consider these additional modifications for further improvement:

  • Sway bars – Stiffer front and rear sway bars reduce body roll without affecting ride comfort as much as springs. Eibach and H&R make versions for the Supra.
  • Coilovers or lowering springs – Lowering the center of gravity and increasing spring rates can transform turn‑in. Brands like KW, Ohlins, and Bilstein have Supra‑specific kits.
  • Adjustable camber plates – Allow more front camber (‑2.5° to ‑3.0°) for cornering grip without ruining tire wear on street.
  • Polyurethane bushings – Replacing control arm bushings with stiffer units improves deflection and feedback.

The Supra MkV forum is an excellent community resource for real‑world experiences and part reviews.

Conclusion: Building a More Capable A90 Supra

Installing Cusco strut braces and upgrading tire sizes are two of the most cost‑effective and impactful handling improvements for the A90 Supra. The braces reduce chassis flex, sharpen steering, and improve alignment retention; wider, stickier tires unlock the chassis’s true potential by maximizing mechanical grip. Together, these modifications create a more responsive, stable, and confidence‑inspiring driving experience – whether on a twisty back road or a closed circuit.

Remember to choose components that match your goals and driving style. For daily drivers, a front strut brace and a high‑performance summer tire may suffice. Track enthusiasts will benefit from rear braces, adjustable suspension, and semi‑slick tires. Regardless of the path, these upgrades will help your Supra handle like the thoroughbred sports car it was meant to be.

For further reading, Cusco’s official product page provides technical details, and Tire Rack’s guide to tire sizes explains fitment considerations in depth.