When it comes to tuning a Skyline GT-R, the Japanese have it all over the
rest of the world. Since the RB26DETT engine debuted in 1989, the Japanese have
been locking themselves in dyno cells and coming up with combos that make
unbelievable power. One of these high-profile tuners is Top Secret.
It’s fair to say that Top Secret’s world revolves around the RB26 powerplant.
You only need to consider they once hauled a Toyota 2JZ twin-turbo out of a
Supra to make way for Nissan power...
The wicked 1997 model R33 GT-R seen on your screen – which is currently for
sale through Sydney’s Autostyle Performance Cars – is a sobering demonstration
of how easy it is for Japanese tuners come up with nearly 450kW at the wheels.
At least, it’s easy when you know the RB-motor like the back of your hand...
Lift the lid on this Skyline and the engine bay scenery is pretty no-fuss.
Somebody knew exactly what to do – and that’s all that’s been touched.
The most obvious upgrade is the fitment of a huge T88-34D turbocharger mounted
proud on a Trust tubular exhaust manifold. The intake to the windmill-like
compressor is a free-flowing twin filter kit featuring an underbonnet heat
shield. The turbine – which works side-by-side with a Trust 55mm external
wastegate – feeds gasses into a big 3½-inch exhaust system. Domenic from
Autostyle says the car arrived from Japan with absolutely no mufflers – a couple
of stainless steel boxes now keep the decibel count to sane levels.
Top-notch intercooling is vital for any highly-strung turbo engine and the
Japanese certainly know how to address this situation. The entire nosecone of
this car is consumed by a monster Trust Drag-spec air-to-air intercooler. No
need for a water spray here – it’d be kinda like pee-ing in the snow... A GReddy
large volume plenum is also bolted onto the standard six-throttle induction
system.
But the real top-secret stuff is hidden away beneath the Nissan valve
cover.
Domenic of Autostyle describes the engine as built to race spec. It includes
HKS rods, pistons and crankshaft plus 264-degree cams with adjustable gears.
And there’s probably a whole lot more that we don’t know about. Life support comes
from a Trust oil cooler and filter relocation kit, a Trust high-capacity sump,
GReddy aluminium radiator and oil catch can.
The car arrived from Japan with a custom-mapped factory ECU but – in order to
suit local fuels and conditions – Autostyle has switched to an A’PEXi Power FC
with local mapping. Larger diameter Z32 airflow meters have also been installed.
The fuel system comprises a high-flow in-tank pump, 660cc injectors and a Nizmo
pressure regulator. The ignition is largely stock.
With 98 RON fuel and a bit of octane booster in its tummy the Top Secret
built R33 has rolled out 436kW at all four wheels on a Dyno Dynamics chassis
dyno. This was achieved with a head-spinning 1.9 Bar (30 psi) of boost.
The R33’s factory active torque-split AWD system puts most of this grunt to
the road thanks to a GReddy triple plate clutch that is surprisingly easy to
live with. Behind this is an aftermarket full-synchro gearbox – we don’t have
any more details on this.
The car hasn’t yet run any quarter mile passes in Australia but, given its
power output and weight, there’s no doubt it will run deep in the 10s. And
that’s not hanging around for something that can be driven on the street without
stalling, overheating, fouling plugs, etc.
The GT-R is already a pretty dynamic handler but it wouldn’t be clever to do
this much to the engine and neglect the suspension. Bilstein dampers, lowered
springs and an assortment of alignment products keep this machine under control.
The factory Brembo anchors have been decked out with Top Secret pads.
Domenic tells us this vehicle is incredibly stable at high speed – to the
point where you can take your hands off the wheel at 260 km/h! This makes sense
when you find the undertray at the front and rear. The towering rear
wing is also adjustable for maximum effect. The body also flaunts aftermarket
skirts, front and rear ‘bar extensions and an unusual fluted bonnet. Note that
NACA duct feeding air to the filters below. It’s all finished in gold paint – a
trademark Top Secret touch.
The wheels seen in these pics are only temporaries that Autostyle had around the place – an aggressive set of Veilside 18-inch rims is soon to be thrown on.
Perhaps not surprising given the lack of mufflers while in Japan, the car
arrived in Australia with a roll cage and a pretty hard-core interior. But Domenic
doesn’t believe in roughing it so he has set the Autostyle interior trim
specialist to work ripping out all the racer-type gear and decking the halls
with miles of leather. Burgundy leather covers door trims, gear lever and
handbrake boots as well as the rear seat and the supremely comfortable Recaro
front seats.
Other interior highpoints include a Momo wheel, aluminium gear knob and an
AutoMeter monster tacho with shift light. There’s also a Pivot electronic boost
gauge and a triple pod of GReddy oil temp, water temp and EGT gauges. A GReddy
Profec B boost controller and turbo timer are mounted under the dash, while the
steering wheel is equipped with controls for boost adjustment and audio
settings. A high-end Pioneer unit heads the audio system.
With the best of Japanese GT-R tuning and some local finishing this R33 is
one absolutely jaw-dropping car. It is currently being offered for sale at
AUD$89,900.