Tunehouse Racing 86

Claiming the crown of ‘Australia’s fastest or most powerful anything’ is a bold statement.

But clocking the fastest lap time for an Toyota 86 or Subaru BRZ at the Yokohama World Time Attack Challenge – Australia’s annual tuner slugfest at Sydney Motorsport Park – goes a long way to certifying such a boast.

Tunehouse’s supercharged Toyota 86, nicknamed THR-86, took only 1min 44.92sec, in the hands of some-time MOTOR cohort, John Boston, to score what no other Toyobaru could match.

And right now it’s sitting in Sydney gridlock, a 37 degrees Celsius summer heat turning the winged coupe into a pizza oven and yours truly into a Super Supreme because the air-con doesn’t work. Well, the oily bits required do, but are probably in a box labeled ‘unnecessary’ at Tunehouse.

And yet the big surprise is that, despite a bitey Xtreme twin-plate clutch and a slight clunk in the Tomei two-way LSD rear end, it’s almost as docile in the urban crush as the stock sportscar it once was.

Tunehouse has owned the 86 since the first of the freshly-minted Toyota’s landed in 2012, and it quickly became an R&D test bed for the Marrickville shop’s go-faster brands, including Japan’s famed HKS. It’s been on a long and carefully orchestrated path to become the beast it is today, each step crucial in developing the various aftermarket gadgets Tunehouse markets for the 86 and its Subaru twin, the BRZ.

In current WTAC guise, though, THR-86 swings a bigger stick. Despite running a modest 0.6bar (8psi) of peak boost and standard engine internals, the engine now produces around 300kW. Ghelis calls it Spec R ‘Plus’, and it’s only for competition use, and not a bolt-on customer package.

Why? Well, it’s not for lack of public road drivability, in fact, the opposite. The engine now feels about on par with a 2.5-litre turbo STI boxer but unlike the Subie engine, throttle response is crisp, response off-idle immediate, and it’s so razor sharp in the mid-range it demands concentrated precision from your right foot.

The key to screwing extraordinary pace from the 86/BRZ breed, as Tunehouse preaches, isn’t purely down to output gains, but in maintaining balance among all areas of a complete go-faster package. Rewind two years, handling and grip were the first things Tunehouse chased for THR-86.

“Out of the box, the 86 has a fantastic chassis but is underpowered,” says Ghelis. “Still, we focused on tyres and suspension (upgrades) to see what the chassis is really capable of. Only then could we chase power, to balance the equation out.”

Tein Monoflex coil-overs, Super Pro suspension, upgraded DBA rotors with THR Clubsport pads, and an HKS Spec L exhaust system completed the initial ‘lightweight’ tuning combination, with a Spec S engine kit added prior to THR-86’s appearance at MOTOR’s own 2012 Hot Tuner Challenge.

By the time the 86’s first birthday rolled around, the Spec R supercharger kit with THR’s custom Ecutek ECU tune, and four-pot front brakes were installed and Boston had the Toyota flying around Wakefield, in 1min 7.9sec, a full 5sec quicker than standard. Tunehouse now claims it’s the quickest 86 ever to lap Wakefield.

When we first went from 98 to E85, power jumped from 222kW at the flywheel to 279kW! Since changing to E85 for racing, we haven’t turned back.”

Tunehouse then pushed suspension development, switching from Tein to custom Bilstein B16 coil-overs, installing Whiteline bushes, swapping rear camber arms, adding custom strut tops and changing geometry. With handling sorted, they sourced wider 9.0-inch Rota rims and Yokohama ADO8R tyres then went for even more grunt.

“Once we decided to enter WTAC, we really took a different approach with the 86,” Ghelis says. “Custom parts were ordered, others were fabricated and we began modifying the HKS GT Supercharger kit.

” In dyno testing, the engine was pushed to a stratospheric 381kW at the flywheel (at just 0.7bar) but detuned to ‘just’ 300kW for WTAC reliability. That’s still twice the factory power rating using standard internals.

“The standard ’box is holding up fine, though the clutch needs replacing beyond about 200kW. We put in a two-way LSD because sometimes on track, the car can lift onto two wheels across the kerbs and we want as much traction as possible, even when this happens.”

But compared to a street 86, this device is mental; it’s a race car with rego plates, albeit one that’s happy at sane speeds or even in insane summer gridlocks. That said, Tunehouse wants more power, grip, aero and quicker lap times and have plans to source an 86 shell and build a dedicated WTAC car from scratch. We’ll be waiting.