The Toyota A90 Supra’s mid-corner understeer, braking instability and lack of steering feedback are caused by a compromised stock suspension setup. Here’s how to fix it…
The A90 Supra is undoubtedly one of the most capable Japanese performance cars on the road today. However, there is significant untapped handling potential in the standard setup – and the vast majority of owners we speak to can sense it.
The Supra recipe sounds promising on paper: turbocharged straight-six, rear-wheel-drive, and a BMW-derived chassis. However, when it comes to the platform both Toyota and BMW clearly prioritised comfort and refinement over outright sporting prowess. This compromise can be found in the substantial oil-filled suspension bushes and conservative factory settings, which create a disconnected feeling during hard driving. That’s bad news for keen drivers who thrive on textured communication from the chassis.
However, as owners have rightly told us, there is a great car in there begging to come out. And we can confirm the A90 Supra responds very well to specific suspension upgrades. From experience, there are three in particular that deliver big improvements to the Supra chassis.
Why the A90 Supra Suspension Needs Upgrading
In an effort to keep a lid on manufacturing costs, BMW and Toyota developed a chassis to serve both the G29 Z4 and A90 Supra. Unfortunately, this platform inherited large, oil-filled rubber bushes capped off with underwhelming alignment settings, blunting what should otherwise be an exciting package.
This focus on road compliance causes notable – and unwanted – suspension movements. The soft rubber bushes flex during hard driving, dynamically changing the suspension geometry. This makes handling less predictable, reduces front end grip, and robs the driver of vital feedback.
Key to unlocking more handling performance from the A90 Supra is stopping those flexing movements and improving suspension geometry. Here Supra upgrades are the parts that will achieve those goals…
Solid Front Control Arm Bushes
One of the most effective upgrades you can make to the A90 Supra is swapping the front control arm’s soft rubber bushes for solid replacements.
The factory bushes (pictured above top left) are rudimentary in design and aimed at improving comfort over handling ability. The rubber part is incredibly thick and soft, and within it you’ll find a lot of oil for absorbing vibrations. The stock bush does that job pretty well, but it inevitably allows too much front control arm movement under heaving braking and when receiving high cornering loads. This creates chassis instability plus excessive steering movement, and means you trust the front axle less as you enter a corner.
Suspension Secrets solid front control arm bushes solve this issue by significantly reducing unwanted flex during fast driving – without sacrificing the everyday usability of the A90 Supra.
Solid bush benefits:
- Sharper steering response
- Improved braking stability
- Increased front grip
- Less geometry change during hard driving
- Enhanced steering feedback
Solid bushes really come into their own during rapid changes of direction, and transform how connected the Supra feels to the road.
Adjustable Camber & Caster Plates
For owners wanting to completely transform the front end behaviour of their A90 Supra, adjustable camber and caster plates open a world of possibilities.
The single biggest complaint we hear about the latest Supra is that it understeers mid-corner. This is largely due to the factory suspension settings, which include very little negative front camber. This is because the stock suspension components don’t offer much camber adjustment.
Why is negative camber important to handling performance? On stock Supras, as cornering loads increase the outside front tyre rolls onto its outer edge. This reduces the tyre’s contact patch, affects grip level, and makes the front end push wide.
Increasing negative camber tips the top of the tyre in towards the centre of the chassis when the vehicle is static. As the car enters a corner at speed, that same tyre roll effect that happened before now brings more tyre into contact with the road surface rather than less. This helps the Supra to generate more grip and less understeer.
The A90 Supra camber plates manufactured at Suspension Secrets are designed to provide far more negative camber adjustment than the factory top mounts. This means you can achieve superior settings for fast road and track driving.
As well as motorsport-grade spherical bearings, our camber plates also incorporate additional caster angle, which generates even more negative camber during cornering. This is otherwise known as ‘dynamic camber gain’ and has the added benefit of increasing steering weight and communication.
Adjustable camber plate benefits:
- Increased front grip
- Greater high speed stability
- Improved steering feel and weight
- More even tyre wear during fast driving
- Improved cornering confidence
Aftermarket camber and caster plates remove one of the big compromises built into the standard Supra chassis – namely, very limited camber adjustment. Suspension Secrets camber plates for the A90 Supra allow you to optimise your setup for fast road and track applications, and are even more effective when teamed with solid front control arm bushes.
Adjustable Rear Toe Arms
The final piece of the puzzle that is the A90 Supra is adjustable rear toe arms. Like the front control arms, the standard rear toe arms use soft rubber bushes that flex during fast cornering. This movement dynamically changes rear toe settings, creating instability and inconsistency at higher speeds.
There’s another factor at play in this area of the Supra chassis, too. When attempting to increase the rear negative camber, the factory adjustment range limits what’s possible. Without more adjustable rear toe arms, it’s practically impossible to achieve the ideal combination of rear camber and toe settings for fast road and track work.
The A90 Supra adjustable rear toe arms developed by Suspension Secrets solve all of these issues. First, by replacing soft rubber bushes with motorsport-spec solid rose joints. And second, by offering significantly greater adjustment range than the standard toe arms.
Fine-tuned rear suspension geometry instills the A90 Supra with greater stability when you hit the brake pedal. Optimised rear camber and toe angles also make the rear end more responsive at corner entry, and deliver much-needed confidence that sufficient grip will be present when the throttle is reapplied through corner exit.
Adjustable rear toe arm benefits:
- Improved rear stability
- Increased rear grip
- Greater cornering consistency
- Optimised alignment settings
- Reduced rear axle movement under load
Combined with the front suspension upgrades mentioned earlier in this blog, adjustable rear toe arms create a far better balanced and confidence-inspiring chassis.
Transforming the A90 Supra Chassis
We always knew there was a great driver’s car lurking inside the A90 Supra chassis. It just takes a handful of performance suspension upgrades to unleash it.
What can be a numb, blunt and ultimately frustrating sports car suddenly comes alive with the right chassis upgrades. Not only do these bolt-on parts deliver greater handling performance on the track, they work extremely well on the road and maintain the Supra’s usability as a daily driver.
Frequently Asked Questions
What is the best suspension upgrade for the A90 Supra?
Supra owners would benefit most from adjustable camber and caster plates, which unlock more negative camber adjustment and deliver the biggest improvement to front end grip and steering precision.
Does upgrading the Supra suspension increase NVH?
Suspension Secrets upgrades utilise high-quality joints and bearings, and are designed to minimise any increases in noise, vibration and harshness.
Does the A90 Supra need a geometry setup after suspension upgrades?
Yes. Any suspension modification should be followed by a professional wheel alignment and geometry setup to ensure the new parts provide their full benefits. All Suspension Secrets parts come with recommended settings specific to your vehicle.
