Do you have a Do-It-Yourself streak? Like that feeling of satisfaction when
you achieve a massive power gain for only a third of what it would cost in a
go-fast workshop? Well, here’s a compilation of cars that are dead-easy and
cheap to work on...
Time to clear out all that junk in the shed and get workin’!
Holden 5.0i V8
When the faithful Holden 5.0 litre V8 was reborn in 1988, it opened up a whole
new era of modification.
The injected 5.0 V8 – as found in VN to VT Series 1 Commodores and
contemporary Statesman/Caprice models – is a great base for anyone wanting to
enhance some late-model V8 muscle. The relatively simple mechanics, the
abundance of parts (OE and aftermarket) and the wealth of tuning knowledge make
this hard to go past.
In base form, the injected 5.0 generates 165kW and 385Nm of torque. It
achieves this with a relatively restrictive intake manifold that’s focussed on
low rpm torque (see photo). If you want to extract real power without resorting
to forced induction, the Holden Group A intake manifold is a direct bolt-on and
– even by today’s standards – it’s a ripper manifold. It employs tuned length
ram tubes for each cylinder, a large volume plenum chamber and dual staged
throttle bodies. The only accompanying mod that might be necessary is a bonnet
hump or cut-out to clear the top of the new manifold.
Oh, and when you upgrade the intake manifold, it’s also the perfect time to
revise the pre-throttle induction system – again, the Group A intake is a very
good set-up. All you really need to do is enlarge the entry to the airbox.
With a free-flowing air intake, you can make the most of a camshaft upgrade.
Of course, there’s only one camshaft in the ol’ Holden V8. There are many
different profiles on the market – all you need to do is chose your desired rev
range and power output. See New Stick for
our article on installing a Crane H286 camshaft in a VS Commodore V8.
The 2-valve cylinder heads are generally good, but the casting dags can be
easily cleaned up at home with a grinder. For applications over about 300kW,
you’re strongly advised to replace the factory cast pistons. The standard
compression ratio is a lowly 8.4:1 to begin with, so a set of high compression
forged pistons is probably on your shopping list anyway.
There are a number of approaches to optimise the 5.0 V8’s engine management.
Take your choice from a custom chip, a Kalmaker reprogram, plug-in Haltech ECU,
interceptor or stand-alone aftermarket management. Note that the injected 5.0
runs a MAP sensor up until the VT.
For all-out applications the Holden engine can rebuilt with a stroker kit up
to about 6.2 litres. The Harrop 5.7 litre upgrade is a popular choice and came
factory fitted to the HSV GTS-R.
If you don’t like the idea of an in-depth backyard engine tear-down you can
always purchase an off-the-shelf supercharger kit. Brand new, a basic blower kit
costs anywhere between AUD$4000 – $8000 but keep an eye in the classifieds – you
can generally pick one up for about half the new price. Ready-to-go intercooler
kits can also be purchased, but if you’re a true Do-It-Yourselfer you’ll tackle
this with a custom set-up.
And, yes, there is more to a Commodore than just its engine. They are easily
upgraded in terms of suspension, brakes and interior.
The potential is almost unlimited.
Daihatsu Mira TR-XX/Leeza
At the opposite end of the spectrum is this – the Japanese market Daihatsu
Mira TR-XX/Leeza TR-ZZ. Both are 15 year old Japanese imports that can be
readily picked up for just AUD$4k (plus ADR-ing).
If you like small performers – and you don’t realistically expect to run with
‘the big boys’ – you’ll love these!
The Japanese-market Mira TR-XX is based on the little L70 Daihatsu chassis
(known in Australia as
the Handivan). The only difference is a big serving of attitude. The little
Kei-classer is made more appealing thanks to a full body kit comprising a rear
spoiler (which surrounds the entire tailgate glass), side skirts, a front lip,
bonnet scoop, central roof-mounted aerial and 12 inch alloy wheels. The ride
height is also a bit lower than everyday Miras. Oh, and some examples also
feature a dual outlet exhaust – a hint to the awesome grunt on tap.
Well, not quite...
Under the bonnet, the TR-XX boasts a turbocharged and intercooled 550cc
three-pot! The EB20-series turbo engine is available in two main specifications
– carby and EFI.
The base version (released in 1986 and continued until 1990) uses a
blow-through down-draught carburettor and a static compression ratio of 8.3:1.
This engine is rated at 38kW and 70Nm (at 6500 and 4000 rpm respectively).
More desirable is the
multi-point EFI version,
which was released alongside the carby turbo engine in 1987. Interestingly, the
EFI engine employs a 0.3:1 lower static compression ratio but power is up to
43kW (at 6500 rpm) and torque steps up to 73Nm (at 4400 rpm). Later (circa 1989)
EFI models are listed with the Japanese regulation 47kW output.
Interestingly, the TR-XX was built in both manual and automatic guises – the
former being the most common. The TR-XX manual version can accelerate to 100
km/h in around 10 - 11 seconds. Obviously, it’s no speed machine – but you don’t
need much more power to get the 570kg kerb mass hooking along! We’ll come to
The overall appeal of the TR-XX is enhanced with its standard sports trim and
instrumentation comprising a tacho and LED boost meter. Air conditioning is
fitted to most examples and the top-line TR-XX Limited boasts power windows. Of
course, the cabin is very tight in terms of width but leg and headroom are not issues for most drivers.
If the commercial-based Daihatsu Mira isn’t exclusive enough for you, it is
worthwhile checking out the Leeza TR-ZZ stable mate. The L100 Leeza reputedly
shares a Mira chassis but flaunts a sportier body with gentler curves. The
biggest downside is almost none of the panels are interchangeable L70. Oh, and
note that a soft-top ‘spider’ version was also released – great for
demonstrating chassis flex... Under the bonnet everything remains identical to the
Okay, so what can you do with these pint-size little tigers?
Well, you can do everything you’d normally do to a larger turbo car - except
everything can be downscaled and is much cheaper.
The exhaust needn’t be anything more than a press bent 2¼ inch system with
an OE cat and muffler off, say, a Falcon or Commodore. For about AUD$200 you can
have an exhaust that poses zero
Similarly, the air intake can be enhanced very cheaply. The easiest approach
is to buy a pod filter and mount it directly on the compressor inlet, but you
might be able to squeeze in the airbox from a larger car. A Holden VL/VN airbox
and filter can be bought very cheaply.
The standard top-mount intercooler is one of the smallest we’ve ever seen.
Everything is relative, of course, so an intercooler that’s considered rubbish
on a R32 Skyline is intercooling overkill on a 550cc engine. Good intercooler
performance should be achievable on a budget of around AUD$100!
Boost – and a whole lot of it – will be required to get the Mira or Leeza
really hauling. Unfortunately, the standard IHI RHB31 turbochargers are
relatively delicate and don’t last long at high boost pressure. An effective
upgrade – which we believe should be a bolt-on – is the RHB32 turbocharger found
on the locally delivered Daihatsu Charade turbo. Those that have survived the
With these mods, you’ll have plenty of wheelspin and straight-line
performance to scare the pants off many Saturday night traffic light demons.
What could be more fun?
Stay tuned for the second – and last – instalment of this series. We’ll take
a look at some hot sixes...