This article was first published in 2005.
When you’re a car enthusiast who has owned the same machine for almost 20
years, chances are there isn’t much left on the car that remains unmodified.
Just take John Whittaker’s 1976 Datsun 260Z for example. The suspension and
brakes are f-a-r removed from the standard Datto parts – and you’d better be
ready for a surprise when you pop the bonnet...
There’s a tuned Skyline GT-R motor hiding in there!
John is the owner/manager of Brisbane Tuning and Turbo Centre and, as you
might imagine, he’s had petrol pumping through his veins for many years. Back in
the late ‘70s, John purchased this RS30-series 260Z from its original owner and
proceeded to give it the performance to run with the hot cars of the day –
namely, Toranas, Monaros, Falcons and Chargers. The first serious round of mods
saw the original L26 in-line six equipped with a draw-through carby turbo
set-up. John says this set-up made quite good power - about 260hp (191kW) at the
wheels - but it lacked the oomph to make it a real on-road ego basher.
After about four years of running a boosted L26, John decided to step up to
the L28 engine (as fitted to the later series Zed). A new engine was pieced
together with a ported head and some beefed-up parts and John achieved his goal
of improving flexibility and torque.
Now fast-forward to the start of the current millennium.
As a workshop owner, John didn’t want to get left behind by the current breed
of performance cars so he took the big plunge – fitment of an R32 Skyline GT-R
engine (RB26DETT). John says there was a lot of work that had to be done to
accommodate the DOHC twin-turbo donk but the similarities between the L-series
and RB-series bottom-end helped make it achievable. John recognised the limits
of the factory engine mounting arrangement and added an upper engine brace to
keep everything sitting where it should.
The RB26DETT was slid into the Zed together with the accompanying GT-R
gearbox. To suit its adaptation into a rear-wheel-drive car, John removed the
front-drive section of the ‘box and performed some custom mods. A modified HKS
single-plate clutch is sandwiched between the engine and ‘box.
The Datto IRS has been revised with Nissan R31 Skyline LSD (R200) rear suspension running
custom driveshafts. John says it’s unlikely the standard driveshafts would’ve
lasted under the stress of a boosted RB26.
A squiz around the engine bay reveals some power-up mods to take the RB26DETT
well beyond its standard 280hp (206kW) power level. The inlet to the compressors
is virtually restriction-free thanks to twin K&N filters and the
turbochargers are based on HKS 25/10s. John says he ran the engine with the
turbos as supplied from Japan, but
after fiddling with the wheels and housings, he managed to pick up torque at both
the bottom and top ends of the rev range. A 3 inch mandrel bent exhaust lets the
An air-to-air intercooler was initially used in the car but the front-mount
placement of the big core didn’t do any favours in terms of maintaining coolant
temperature. The alternative was to switch to a compact water-to-air intercooler
set-up using a PWR heat-exchanger, electric pump and dedicated front radiator.
John isn’t entirely happy with the set-up on the track – some experimentation
with pump flow and radiator heat-exchange properties might be needed. The
intercooler plumbing is made from mandrel bent stainless tube and twin GT-R
blow-off valves are fitted.
To avoid engine destruction on the racetrack, John has upgraded to a thick
core aluminium radiator with a large diameter electric fan. An Odyssey battery, isolator switch and oil catch can are neatly nestled into the rear of
the engine bay.
The task of controlling fuel, timing and boost pressure is given to an
Autronic programmable management system. Fuel is supplied by a set of six Mazda
RX-7 (Series 4) injectors and a 700hp Bosch Motorsport fuel pump drinking from a
swirl pot. The ignition system is stock with the addition of an Autronic CDI.
Boost pressure is limited to 1.2 Bar (17.6 psi) and you’ll find a maximum of
448hp (329kW) at the wheels. John says peak power is attained at 7000 rpm but
with the recent turbo tweaking and careful tuning, the car produces strong
torque all the way through the rev range. There’s plenty of punch available to
kick the rear-end sideways on corner exit.
“The car is pretty neutral in terms of handling,” says John.
“It’s quite controllable and, when you want it, you can make it power
oversteer,” he says.
The all independent strut suspension uses coil-overs that are custom made by
Brisbane Tuning and Turbo Centre using adjustable Koni dampers as the base.
Custom adjustable swaybars were also fabricated and a carefully chosen group of
bushes are replaced with Nolathane items. John says the car is still driven
every day and it was important to maintain an acceptable ride quality.
Braking is improved thanks to R32 Skyline calipers and discs
together with a Holden VL rear discs. John also added a larger brake master
cylinder and braided lines but fell short of installing a hydraulic handbrake –
he’d prefer to keep the original cable-operated system. Despite the substantial
improvement, John says the brakes are still pretty marginal – he plans to switch
to R33 Brembos or AP monster anchors.
The classic Zed body is standard with a fresh splash of original green pain
courtesy of a friend. An aftermarket front lip was added back in the late
‘70s/early ‘80s and a new rear bumper was about to be fitted after our shoot.
The previous one got a li’l bent at a recent track outing...
Inside, John has kept much of the '70s Datto feel. The dashboard is
standard and retains the factory tacho (using an adaptor off the Autronic
ECU) and an oil pressure gauge is integrated where there's normally a clock.
A boost gauge and shift light are also added to the steering column. The
standard steering wheel remains and there's an aftermarket driver's seat and
harness for track purposes. A new set of race seats are soon to be fitted.
The area behind the front seats has been stripped and a custom rear
suspension tower brace is installed.
Rolling on its 16 x 8 alloys and Toyo road-legal slicks (which have now been replaced with Silverstones), John has taken numerous trophies in the historic
racing class. And we know what you’re thinking – it won against old HR Holdens,
Anglias and Minis. Wrong! This machine has snatched glory
from hairy-chested monsters such as replica Ford GT40s - get the picture?!
John is justifiably proud that the car has been built entirely in-house and
is frequently street driven. With a move to Silverstone semi-slicks he’s hoping
for a bit more adhesion to further reduce lap times. And it’ll need all the
adhesion it can get when John follows through with his plan to build a RB30/RB26
“I think it will arrive somewhere around 650hp (478kW) at the wheels and I
want to make plenty down low – 200hp (147kW) at 2000 rpm is what I’m after,” he
Brisbane Tuning and Turbo Centre
+61 7 3393 1588