Aussie tuner builds world's most bombastic GT86. With over 1,000bhp

“I guess you could say that we went and did a ‘thing’. I guess you could also say that it probably isn’t the smartest, or most logical thing we have ever done either!”

Music to Top Gear’s ears, then. Ladies and gentlemen of the Internet, prepare yourselves for the most bombastic Toyota GT86 to have ever seen the light of day. Following the news of a modified 86 with a Ferrari 458 engine comes this modified 86, developed by the hardy folks over at StreetFX Motorsport in Australia, who, after being ‘sick’ of only getting 545bhp out of the standard boxer engine, decided on a wholesale engine transplant and big, big power. The engine in question? The V6 from the R35 Nissan GT-R.

StreetFX picked up the 86 in 2012 with mild plans. Plans to make it a ‘mild street/track car’. At this stage, there was no intention to turn it into the intergalactic vessel it would soon become.

Here you see it with its first set of mods – a ‘Rocket Bunny’ wide body kit. For the next year or so after purchase and the Rocket Bunny installation, the 86 went through various states of tune, from turbos through to a twin-charge setup (both turbo and supercharging). As mentioned, the most they could squeeze from the four-pot was 545bhp, and the team were plagued with head gasket problems and injection failures. “Turning the boost up past 21psi just wasn’t resulting in more power,” StreetFX explains.

So talks began with GT Auto Garage, who are apparently the ‘go-to’ guys for anything R35 GT-R related. A masterplan was hatched: the boxer engine would be binned in favour of a new engine.

“The logical option was sourcing an R35 GTR engine,” they said, “since well, it had never been done before, and we are a little bit insane.”

Now you’d think the base Nissan GT-R’s power would sate StreetFX’s appetite. But you’d be wrong. They decided to modify the 3.8-litre V6 using a 4.1-litre ‘stroker’ kit, along with a turbine kit. But even at this stage, they weren’t sure whether the tall, heavy Nissan block would fit the snug engine bay of the smaller, lower boxer engine.

So they fitted a dry sump kit and managed to find a six-speed sequential gearbox that could strap to the back of the Nissan motor. The people behind the gearbox? Albins, who are “responsible for the gearboxes in every Australian V8 Supercar Race car”. Tough, then.

StreetFX then went to Motec for an ‘air-powered paddle shift’ kit too, which promises “super fast shifts and no ugly gear stick”. It’ll all be channelled through a 8.8in Ford Mustang differential to the rear wheels, along with a ‘Full Blown Motorsports’ diff conversion kit.

With the engine and gearbox sorted, the next task was, um, shoving it all into the engine bay and crossing many fingers and toes. The car was sent back to GT Auto Garage who used the engine mounts from a Nissan Silvia, modified the factory cross member, installed a new gearbox cross member and cut the transmission tunnel to accommodate the wider, taller gearbox. Direct Clutch helped with sourcing a multi-plate item that suited the team’s power requirements.

“Magically we still have around an inch to clear the hood,” StreetFX said.

GT Auto also welded up some new exhaust manifolds to accommodate the HKS turbos and wastegates, “sitting them low and forward”. The team reckons on minimal turbo lag, thanks to short intercooler pipes.

We’re told the engine in the pics is actually a spare to test fit; a fresh set of a forged 4.1-litre HKS internals would be installed in a brand new block (direct from Nissan). This is because the engines have a plasma coated bore, meaning they can’t be honed or machined anywhere else.

“The standard bore of 95.5mm is retained,” StreetFX explains, “only the stroke is altered and increased to 95.5mm. The forged pistons are 80 grams lighter than the factory items.”

So here it is. And isn’t it a little bit excellent? The team will keep the interior, including the dash, stereo and even air-con. Oh, and fit a roll cage. Quite a sensible move, that.

“The ultimate goal of this car is a combination of time attack (circuit), street use and roll racing,” explains StreetFX. “Not being built for one specific purpose will mean there are sacrifices for every category, but given the level of engineering and thought that has gone into this build, with a power goal exceeding 1000whp on Martini Racing E85 – it should comfortably be able to be used for a bit of everything.”

Yup, that’s 1,000 horses at the wheels. Be afraid.