It’s amazing how important it is to get good advice when modifying a car.
Just ask ‘Jobe’ of Brisbane.
“At one point I just wanted to burn it,” he says about his Nissan S15
But these days he talks with a completely different tone. He’s achieved exactly what he wanted.
Having previously owned an 11 second 360ci VK Charger and being one of the
first people in
develop his LS1-powered SS Commodore, Jobe recently spoilt himself with a rare S15
200SX Spec S GT. Jobe is an avionics technician on F-111 strike/bombers and
simply loves to get his hands on things that go fast.
Jobe picked up this Spec S GT about a year ago in absolute showroom condition
– we’re told the original owner drove it only on dry, sunny days. And there were
a couple of bonus tweaks under the skin – like a Blitz front-mount intercooler
kit, Blitz exhaust system, pod air filter, extra boost and Tein adjustable
“The car drove great when I bought it – I was really impressed,” says
Unfortunately, when he acted on some recommendations,
the whole package fell into a heap.
“I was told to put on a high-flow turbocharger and rising rate fuel pressure
regulator and that made it an absolute pig,” says Jobe.
At this point, Jobe took the car to Kelvin and Bill of Brisbane’s C-N-J
Motorsport. C-N-J had already sunk their claws into Jobe’s SS Commodore and
achieved some impressive numbers with limited mods. On the rollers of their Dyno
Dynamics chassis dyno and with an air-fuel ratio meter up its tailpipe, it
became obvious something was very, very wrong. Extra-lean mixtures were traced
back to a faulty fuel pressure regulator.
The standard fuel pressure regulator was refitted and another approach was
taken – namely, bigger injectors, a high-flow fuel pump and an Autronic SMC
programmable ECU. The Autronic unit takes a load input from a MAP sensor which
replaces the Nissan airflow meter. Note that C-N-J also has a plug-in adaptor
loom to enable neat an’ easy fitment of Autronic management to the S15. These
mods improved driveability but, still, the engine was very laggy and power
output was well under expectations – only about 180kW at the wheels.
“I remember it took until about 4500 rpm before it did anything,“ says Jobe.
At this point he was willing to try anything.
Jobe then threw on a set of Gonzo extractors in an attempt to
improve response. The new pipes gave a small but noticeable improvement in
response and about 5kW extra at the wheels.
Still not enough.
About now Jobe did some in-depth research and
purchased a replacement turbocharger – a GT28RF unit with an internal wastegate.
This was fitted to the existing Gonzo exhaust manifold and, after a bit of other
fiddling around relocating the ABS unit, the improvement was monumental.
The existing pod air filter was replaced with a modified version of the
standard airbox with a silicone pipe into the turbo compressor. A high-flow
adaptor pipe lives in the place of the standard airflow meter. A Blitz blow-off
valve can be found on the intercooler pipe leading into the throttle.
“All of a sudden it was insane,” says Jobe. It was supremely responsive,
torquey and gave plenty of top-end.
Given the newfound grunt, it’s no surprise the standard clutch started slipping
with 15,000km showing on the odometer. Jobe wanted to maintain driveability so
he went for a heavy-duty full-face organic clutch - he didn’t want something
that might snap the factory 6 speed ‘box.
With an output of around 200kW ATW on 22 psi boost, everything was running
sweetly until a strange missing problem appeared on the scene. The car was
dropped off at C-N-J for 6 weeks (while Jobe went away for work), during which
it was discovered there was a lifter problem.
While the top-end was pulled apart, Jobe made a deal with C-N-J that they
could use the car for the development of an effective camshaft and cylinder head
package. Bill from C-N-J tells us they came up with a custom ‘mild’ cam profile,
which works with the standard variable inlet cam timing system. The higher lift
cams are fitted along with upgraded valve springs and off-the-shelf ‘rocker
stoppers’. The DOHC head also received some custom mods.
Once tuned, and with boost pressure eased to around 20 psi, the S15 now kicks
out 229.7kW at the wheels. This dyno graph also shows the meaty bottom-end and
Jobe has subjected the car to a considerable number of quarter mile passes.
His best time so far is a 12.45 – with the air conditioning switched on and poor
traction through the first two gears... Some sticky rubber would almost
certainly drop a tenth or two.
“It definitely goes quicker than people think it will with the power its
making,” says Jobe.
While all of the engine antics were happening, Jobe also looked into
improving the car’s on-road poise and handling.
“The Tein struts that were fitted aren’t meant for Australian roads – they’re
for a smooth surface,” says Jobe.
“I remember I’d hit a bump and the arse would come out. It was scary to put
my foot down going around a corner,” he says.
Interestingly, the solution was to rebuild the Tein struts using
locally-available Koni adjustable inserts. This conversion was carried out by
Fulcrum Suspension in Moorooka. A pair of ‘pineapple’ bushes locate the rear-end
and low-compliance rack bushes improve steering feel and response.
“Now I can throw the car into a corner and it sticks like glue,” says a more
than happy Jobe.
The new suspension also provides a more attractive ride height, which is
complemented by a set of 18 inch JR Racing wheels wearing 235/35 Falkens.
According to Jobe, he does “some serious skids in them” and they are lasting
well. The 200SX GT was also factory-fitted with a rear wing, which Jobe replaced
with a wing-less boot lid. You might also notice the aftermarket taillights,
clear side indicators and clear bulbs.
Inside, the trim is standard Spec S GT fare with leather and exlusive shiny
bits. Jobe has added an AutoMeter boost gauge in an A-pillar pod and installed a
high-quality sound system. No need to go overboard here.
“I’m really happy with how the car now feels on the road,” says Jobe.
“It all comes down to good advice.
“I remember C-N-J asking me exactly what I intended to do with the car and
they took it in that direction. They also built it to last – I’ve had no
problems with the engine and gearbox,” he says.
But using the car as an everyday ride to the Amberley Air Force base does
take its toll in other ways.
“It’s really annoying that I can’t avoid getting stone chips in the paint so
I’ve now bought a Jeep Wrangler which I’ll start using as my everyday driver,”
And what words of wisdom does Jobe have to share given his turbulent affair
with his S15?
Just one thing really...
“Once you’ve found a workshop that does the right thing by you, make sure you
stick with it!”
C-N-J Motorsport +61 7 3290 3966
Jobe would like to thank Kelvin, Bill and the team at C-N-J Motorsport,
Fulcrum Suspension in Moorooka and Gonzo of Gonzo’s Racing Products.