VOLUME 2 TRACK SESSIONS
Photos by Tim Harris
4 MIN READ
The tips in this video are provided to enhance your driving experience on race tracks only and are not recommended for normal road driving. All driving and associated tips were provided by professional Motorsports drivers from Norwell Motorsports about GAZOO RACING CLUB track days, and are not a substitute for the road rules & regulations that operate in your state or territory. Please drive safely.
Related viewing: Track sessions: Episode 1 - How to prepare your car for a track day
Understeer occurs when the front tyres lose traction while cornering, pushing the car wide. Because the car pushes wide, it looks as if the driver hasn’t applied enough steering – hence the name.
This loss of traction to the front tyres is caused by a conflict between speed and steering: if the speed is too great for the radius of the corner, the front tyres lose grip, the car becomes imbalanced and it stops responding to the steering wheel. So even if the steering angle is correct for the angle of the corner, the car will push too wide if the speed is too great.
If you’re understeering the car will be pushing too wide around a corner, so your reflexes might instinctively tell you to apply more steering. Sadly this will make things worse: the tyres are already over their grip threshold, so steering harder will reduce grip even more.
Instead, release the throttle to regain traction to the front wheels. Rebalancing the car will naturally tighten the radius of your turn.
To really understand the physics of understeer, picture turning around a big circle in a steady state: if you hold the speed within the limit of grip control, you could hold the line around the circle infinitely.
But if you increase speed, the car will push wide. If you attempt to bring the car back on line by turning the wheel more and without reducing the throttle, all you’ll do is tighten the radius of your steering angle. This means that even more speed will need to be washed off to bring it down to the grip limit for the radius of your new, tightened turning angle.
So instead of correcting understeer with the wheel, come off the throttle and take the speed back under the grip limit to load up the front tyres and return the weight to the front of the car, and bring it back on line.
To correct understeer step-by-step:
One of the key warnings that you might be understeering comes from the feedback through the steering wheel. If you’re on the racing line, the steering wheel should feel well balanced and weighted. If you’re understeering and losing grip to the front tyres, the turning resistance will feel less weighted. A relaxed grip will help you better detect this feedback, so try not to hold the wheel too tightly.
Be aware: if you detect understeer through the wheel it likely means you’re already understeering, so read on for tips to avoid it in the first place.
Avoiding understeer is all about understanding the corner, much of which comes down to having good track vision.
To optimise your cornering, you should understand the shape of a corner before you attack it. Try to look beyond the windscreen to give yourself a long and broad field of vision. This way you’ll be aware of the corner earlier, and you’ll give yourself more time to think about and execute your move. You’ll have more control.
To refine your track vision, work on these steps:
If you brake too hard or enter the corner with too much speed, you might find yourself running out of grip and understeering. Practicing smooth transitions on and off the brakes will help you to not only avoid understeer, but to take corners as quickly as is possible.
Driving the GR Yaris in Sport Mode sends 70 percent of the torque to the rear wheels, which means it will naturally understeer modestly. But this can be transitioned into equally controlled and restrained oversteer.
Generally, the chassis are set up to react neutrally to gentle push on understeer. Which is the safe option with this much power and a 2.56-metre wheelbase. Keep your right foot in and, as it pulls itself through a bend, ease the throttle. This will ease the line and, if you lift off the back, will get quite loose.
Because the GR Yaris lets you use the throttle and the brakes together, you can even try a left-foot brake to slow and balance the chassis through the turn. Careful though, those brakes are stupefyingly powerful, with great pedal progression. Most impressive is how much traction is available, and how early you can get flat on the throttle while exiting a corner, which is a good marker of solid engineering.
Driving the GR Yaris in Track Mode means for more grip from the front axle, resulting in much less speed-sapping understeer. Plus, in the GR Yaris Rallye with 50 percent of the power going to the front wheels, the Torsen Diff is there to pull you out of a corner.
There’s a pleasing, reassuring handling balance to the GR Supra in its sportier mode – a bit of understeer on the way in, a bit of oversteer on the way out. With stability control set to ‘have a little slip’ but not ‘off,’ you get to feel the balance: steering that’s smooth with a hint of entry understeer, a hint of exit oversteer and the knowledge that you could have a lot more if given the opportunity.
The GR Supra’s low ride height is supported by adaptive suspension and it’s eight-speed automatic transmission. The suspension system delivers tailor-made damping forces based on road conditions and driver input, combatting understeer at high lateral G-forces.
To further enhance the GR Supra’s handling, the car’s equipped with standard active differential, which uses an electric motor and multi-plate clutches to control torque distribution between the rear wheels. The system can put up to 100% of its power output to a single wheel, which helps maintain speed in corners while reducing oversteer and understeer.
The car tends to 'lose rear toe in' on corner entries, which really helps the car rotate into these corners and eliminate understeer. On a tighter, twistier track, this can be thrilling and really easy to control. If you go a little loose on the entry, it grips up as you exit the corner.
This means you can hang the tail out around any corner you choose. With the medium traction control mode engaged, the GR Supra gives about 15 degrees of slip before the ECU and diff move power around to straighten you out. Under hard braking, too, where a normal short-wheelbase car gets skittish, the electronic locking differential – which basically works like a torque vectoring system – keeps things in control.
Coming next issue
Track Session Episode 3: Trail Braking
The tips in this video are provided to enhance your driving experience on race tracks only and are not recommended for normal road driving. All driving and associated tips were provided by professional Motorsports drivers from Norwell Motorsports about GAZOO RACING CLUB track days, and are not a substitute for the road rules & regulations that operate in your state or territory. Please drive safely.
Discover their drive experiences and driver training programs that Norwell Motorplex have to offer: norwellmotorplex.com.au
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