Say the words ‘diesel Hilux’ and ‘power’ in the
one sentence and you’re sure to raise eyebrows, if not cause a smirk of
disbelief. Even with 120kW and 343Nm of torque, the sheer size of the new Hilux
is sure to mitigate against anything likely to be faster than a snail. Isn’t it?
Well we can’t talk for the standard car, but we can say that a diesel Hilux running a
power-up kit from Queensland’s Taipan XP is sure to put the cat amongst the
pigeons.
The kit – which comprises a 3-inch exhaust, Xede
electronic engine management interceptor, Safari intake snorkel and K&N
filter – gives an amazing increase in performance, without any of the normally
associated downsides like exhaust drone or engine stutters.
But before we get into the detail on the kit,
let’s take a look at the engine - it’s one of the most sophisticated diesels on
the local market.
The Engine
Sweeping 3 litres, the all-new four-cylinder
1KD-FTV engine uses twin balance shafts and a four-valves-per-cylinder head
design with centrally located injectors and in-piston combustion chambers. To
maximise swirl, the two intake ports for each cylinder have different profiles.
One intake port in each pair is also fitted with a vacuum-actuated swirl control
valve. Valve actuation is by twin overhead camshafts acting directly on the
valves via shim-less lifters.
Engine management uses a 32-bit engine control
computer with on-board diagnostics and a limp home system. The systems features
electronic throttle, a water-cooled variable-vane turbocharger and common rail
fuel injection. The engine management system uses an atmospheric pressure
sensor, intake air temperature sensor and a hot-wire air-flow meter. Idle speed
control and high-load air-conditioner cut-off functions are included.
The turbo vanes are adjusted by a DC motor, acting
under the control of the ECU. In addition, the turbo has an intake shutter to
improve exhaust gas recirculation performance and reduce NVH during idling,
deceleration and engine shut down. The variable vane turbo is said to reduce
turbo backpressure at medium to high rpm, to improve output and fuel efficiency,
and reduce emissions.
The electronic injection system has multi-pilot
injection control, to determine the volume, timing and time interval between
pilot injections and main injection. Pilot injection comprises a series of small
injection phases before the main injection phase. It smoothes the start of the
combustion pressure curve, so reducing combustion noise. (See
Common Rail Diesel Engine Management, Part 1 for more on electronic
diesel engine management systems.) The fuel system also includes a fuel cooler
to maintain fuel viscosity.
Exhaust
The Taipan XP kit exhaust uses 3 inch pipe
diameter. The mild steel system has a ceramic coated dump-pipe that is complete
with a threaded bung to allow the fitment of an Exhaust Gas Temperature (EGT)
probe during tuning.
Following the dump pipe is a 200-cell aftermarket
cat converter...
...and a braided flex-joint.
A Taipan ‘vortex’ muffler follows. Taipan didn’t
want to divulge the internal details of this design but suggested that the
company’s testing had shown this muffler to work very well.
After that there’s a small resonator and then the
tailpipe.
The exhaust costs AUD$1350 supplied and AUD$1450
supplied and fitted. The company makes the point that all the nuts, bolts and
gaskets are included and that the exhaust can be fitted with the vehicle on the
ground.
Intake
Supplied as part of the power-up kit is a Safari
snorkel and a K&N filter.
The filter fits in the standard airbox and costs
AUD$165.
The snorkel costs AUD$600 fitted.
The Xede
The Xede electronic interceptor is produced by
ChipTorque. It is used to lift the boost pressure from 16 psi to 18 psi (both
max figures) and to alter the diesel fuelling. Interestingly, ChipTorque chief
Lachlan Riddel suggested that while changes in injection timing were trialled,
the increase in engine noise and harshness and a lack of decent torque
improvement meant there was little point in pursuing this approach. However,
judicious increases in fuelling and the small boost lift were very successful.
(Incidentally, as far as we know, this is the first aftermarket diesel
modification in Australia to electronically increase turbo boost pressure on a
variable vane turbo.)
The cost of the Xede, fitted and dyno tuned, is
AUD$1490.
The Results
We were able to drive the car with the complete
kit in place, and then with the Xede engine management interceptor bypassed.
With the full kit in place, the Hilux was an
impressive truck. There was absolutely no exhaust or intake noise (yes, even
with the 3-inch exhaust!) and the car drove with superb docility in
5th gear at 1000 rpm. But then, when you dropped back a few gears and
nailed it, the turbo noticeably came on boost around 2500 rpm and the engine
pulled strongly to 4000 rpm (redline is 4500 rpm).
Apart from the urgency with which boost arrives,
the car feels absolutely factory to drive – and that’s a huge compliment! In
fact, so strong was it that we stepped out of the machine looking for ‘4 litre’
badges, to be stunned to see the ‘3.0’ written on the side.
With a gentle launch, air-con running, a full fuel
tank (but no load in the tray) and a hot day, the Hilux did the 0-100 km/h
sprint in about 12 seconds flat.
ChipTorque then bypassed the Xede and we took the
Hilux for another drive. Performance was noticeably duller, especially in the
mid-range and top-end. In fact, in this form there wasn’t much point in taking
the engine past 3500 rpm. A 0-100 km/h in the same conditions revealed that the
time had stretched to 14.0 seconds...
Dyno curves were available to show the
power-at-the-rear-wheels with and without the Xede. (So the red line on the
graph already includes the exhaust, K&N and snorkel.) With the fitting of
the Xede, peak power went from 99kW to 117kW – an amazing 18 per cent gain.
However, the improvement is anything but peaky, extending right across the rev
range. Incidentally, Lachlan Riddel said that he’d pulled back the tune a
fraction (say 1-2kW) from the figures shown in this graph in order that the
system was further from its in-built limp-home mode.
Taipain XP suggest that with the modifications,
fuel consumption has actually improved. Kerry Haines, Taipain XP Managing
Director, says that around-town fuel consumption has gone from about 550km per
tank to 650 km per tank and as much as 700km on the highway.
Conclusion
We can’t vouch for the fuel consumption figures
but we can say that the performance of the Hilux in kitted form is excellent.
And the icing on the cake is that the modifications retain all the refinement
and driveability of a factory car.
Bring on more powered-up diesels!
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