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Tuesday 13th November 2012


GT86: THE NEXT STEP

Where next for the GT86? PistonHeads drives two prototypes with proposed factory upgrade packages...


Question: should the Toyota GT86, or its Subaru twin, be any grippier/faster/swankier? Or would that spoil the Prius-tyred purity of this wonderful regenerator of simple cars and accessible handling fun?

Blue prototype uses officially sanctioned mods
Blue prototype uses officially sanctioned mods
Tricky one. If you're Toyota, though, you have to do something to keep the GT86 marketable through its life cycle. And given the brilliance of the GT86's rear-wheel drive handling, it might almost seem a shame not to let it corner faster and generate higher-g thrills.

We've been driving some development cars which show where the GT86 is headed next. Not the much-speculated-upon convertible, still unconfirmed, but a GT86 tricked-up with TRD (Toyota Racing Developments) modifications and a potential factory-built, harder-edged addition to the 'official' range. Two different ways of achieving similar results, and wildly different outlays to get there.

TRD has been selling GT86 enhancements in Japan for a while, and the catalogue will be offered in the UK from early next year. The orange TRD-tweaked GT86 waiting for us at the ParcMotor test track outside Barcelona (a brilliant autodrome tumbling up and down through sweeping hills, much like the Osterreichring or the Mount Fuji circuit) has about 16,000-worth of modifications. Visually obvious are the deeper, more aggressive front and rear bumpers/valances and matching sill covers, plus a simpler rear spoiler and a four-tailpipe exhaust system. Black 18-inch wheels wear 225/40 Michelin Pilot Sport tyres.

Copper-coloured car gets pick of TRD parts
Copper-coloured car gets pick of TRD parts
Range expansion
A TRD-badged, range-topping GT86 will join the UK line up at the same time as the TRD components catalogue goes live, which will feature these cosmetic changes plus revised interior leather with embroidered '86' badges on the headrests. Our test car, however, has some deeper changes. Behind those wheels are bigger brake discs clamped by Brembo monobloc calipers, and Kayaba (KYB) dampers adjustable for ride height (set here at 15mm below standard) and damping force. The springs are 20 per cent stiffer and there's an additional carbon fibre brace between the front suspension towers.

In all, then, it's an authentic representation of what an owner might want to do to make his/her GT86 a bit harder-edged. There's an interior to suit, too, with three extra round gauges (oil temperature and pressure, water temperature) where the information screen normally sits. So it's goodbye to the stereo.

More grip, more poise but is it more fun?
More grip, more poise but is it more fun?
The two pairs of tailpipes emit a deeper note, but not a loud one. This TRD-developed rear exhaust box eases top-end breathing and liberates a few more hp, but subjectively the engine feels as normal apart from a slightly sharper response. Piling into the ParcMotor's first bend, however, shows a GT86 significantly altered in its handling feel.

Harder edge
Instead of quickly building up a slip angle calling for an interactive balancing of your steering and throttle inputs in usual GT86 fashion, the TRD car hunkers down and tracks with a precision closer to a track car's. You can still alter the handling balance with your right foot, of course, but you'll probably be going faster, the breakaway will be snappier and you'll have less time to think. There's less feedback thanks to the tied-down suspension but more g-force, and the brakes are magnificent with a powerful, solid, progressive bite.

TRD-branded Brembos among upgrades
TRD-branded Brembos among upgrades
This is potentially a faster GT86 around a track, but is it a better one? For the road I suspect not, given that the suspension is pretty firm as standard. And, curiously, I found myself arriving at the circuit's chicane faster in a standard GT86 than in the TRD car. That's probably because the standard car is easier for an average driver like me to drive near its edge, because it tells you more.

OEM mods
Gain some, lose some... And so to the dark blue development car that's likely to become an extra mainstream derivative. Here, everything has to be engineered and certified to factory-spec standards, which is why its rear tyres are the same size as the TRD's but the fronts have a 215 section, to give the factory-required clearance from the wheelarch. The wheels are BBS, the brakes and springs remain standard, but the dampers are Sachs units uprated over the standard Showa fitment.

Wilder looks aside it's a softer set-up
Wilder looks aside it's a softer set-up
There's a plate-type limited-slip differential instead of the standard Torsen unit, with a final drive ratio shortened from 4.1 to 4.3 to one. The aerodynamics kit includes a large rear wing, the ensemble apparently effective from as little as 30mph. A different flavour of TRD exhaust has two large-bore tailpipes, and a possible preview of the putative convertible's way of ensuring torsional stiffness comes in the form of door latch stabilisers - plates which slide together around the latch to jam the door against its aperture. "It makes it possible to tune a car's body stiffness," says GT86 chief engineer Tetsuya Tada, "because it isn't always best to have the most rigid body. A certain amount of flex in the machine helps the human. We could even tune a track car to have different degrees of stiffness in each side."

Tyred out
Our test car is again in Michelins, but production versions will have bespoke Bridgestones or Dunlops. "The original idea was not to make the GT86 tyre-specific," Tada says, "but here we are not asking tyre manufacturers to compensate for weaknesses in our car. We can get 100 per cent out of any tyre, so we said to them, 'Make your best.'"

Wing does actually make a difference
Wing does actually make a difference
Tada reckons the Sachs-damped GT86 rides better than the standard car, and certainly its relative suppleness combined with tight control of big body movements makes it easier to experiment with than the TRD car. Like that one it grips hard, but there's a touch more initial understeer to lean against and you feel you can trust it more in a long, fast corner.

The shorter gearing makes the acceleration a bit punchier, while the exhaust makes a deep, powerful burble with a hint of a flat-four beat and some great fluffs and pops on gearchanges. The whole effect is a more focused version of the standard car although here, too, you might miss the regular article's instant chuckability on the road. And here's the crunch: Tada reckons this car would cost just 800 more than the current standard GT86 to build, yet it's ultimately nearly as effective on track as the TRD car and rather more friendly to drive. Expect it in the pricelists next year.

Improved damping really counts
Improved damping really counts
In other developments, Tada has got together with all the high-quality aftermarket tuning companies to ensure they have proper GT86 data. This new strategy, he hopes, will eliminate sub-standard parts and protect everyone's reputations. 'Our original intention was to create a capable blank canvas,' he says. This could result in tuning packages specifically for street, track, rallies or drifting, all properly developed.

As for extra power, Tada rules out turbocharging for the simple reason that there's no room for it in the exhaust system of such a low-mounted flat four. Supercharging, then? In reply, Tada-san just smiles...









Author: johnsimister