Wow! Now here’s a 15 year old Japanese import to grab your interest.
The AW11 (aka Mark 1) Toyota MR2 is a pretty niche kinda vehicle to begin
with. With only two seats, a mid-mount engine and rear-wheel-drive, it’s widely
seen as a modern equivalent of the old Fiat X-19. But what happens when you add
a supercharger into the mix?
Look out!
The Japanese-market MR2 Supercharged is one of the most exciting vehicles
we’ve ever driven. Unlike its turbocharged rivals, this machine is supremely
throttle-responsive and delivers a strong punch across a huge rev range. We’d
believe it if somebody told us there was a tuned 2.0 engine under the lid – not
a little 1.6!
In AW11 guise, the 4A-GZE 1.6 litre DOHC 16 valver puts out relatively modest
107kW at 6400 rpm. However, it’s the average output that grabs you – peak torque
is 186Nm at 4400 rpm with ample torque either side.
About now you may be wondering whether the 4-GZE is more powerful than 107kW.
Well, it is – but only in later models. The AW11-spec 4A-GZE employs a vane
airflow meter, TVIS dual-stage intake manifold, distributor-type ignition, knock
sensor, 8.0:1 static compression ratio, top-mount air-to-air intercooler and a
mild 8 psi of boost pressure. We believe later versions use a higher static
compression ratio and a MAP-sensed induction system. The supercharger is a
positive displacement roots-type, which is controlled by an electro-magnetic
clutch.
Most examples of the supercharged AW11 come fitted with a 5 speed manual.
This ‘box incorporates relatively wide ratios and comes with a large diameter
clutch. Note that a strengthened 4 speed automatic transmission was also
produced.
Like many supercharged MR2s, our test example came fitted with a couple of
aftermarket modifications. We’re told it had a replacement supercharger pulley
kit (for increased boost pressure) and it appears that an aftermarket muffler
had been installed. The clutch was also grabbier than we’d expect from an OE
item. Given these mods, we recorded a 0 – 100 km/h time in the easy low 7 second
range. With some fine-tuning of the launch technique and shift points we expect
6 second 0 – 100s.
The handling of the MR2 has always been the cause of much discussion. And
with good reason!
The MR2 is one of those vehicles that fits like a glove and very responsive
to steering, accelerator and brake applications. It feels great when you give it
a casual flick, but push a bit harder and you’d better be ready to catch it... The
MR2 has a bit of understeer in the early stage of a corner but toward the middle
and later section it switches into oversteer. The rate of attitude change is
very fast – certainly enough to catch out many drivers, especially on a wet
road.
Note however, our test vehicle had been fitted with aftermarket rear
suspension.
The AW11 MR2 employs strut suspension at each corner, with the rear using
trailing links and dual lateral links. A front swaybar is also installed with a
rear swaybar introduced in 1989. The mid-mount engine and a centrally mounted
fuel tank contribute to the AW11’s balanced 44.5/55.5 front-to-rear weight
distribution.
Another gripe is the bordering-on-heavy steering. Interestingly, the AW11 MR2
was not equipped with power assistance... On the upside, the AW11’s turning circle
is very tight.
The brakes – ventilated discs at the front and solid discs at the rear – are
more than capable of slowing the 1080kg MR2. It appears that ABS was not
offered.
There are two versions of the MR2 Supercharged – the G model and G Limited.
Our test vehicle was an entry-level G and came with only basic luxuries such as
power windows, central locking, supercharger boost LED and a 7500 redline tacho.
Removable roof sections were also available on some models.
Despite its compact size, the MR2 offers a decent amount of space for its two
passengers. Headroom isn’t a problem for most people, but the driver doesn’t
have much left knee space. Knickknacks can be stored in the glovebox or in a
couple of small compartments in the centre console. Depending on your seating
position, it might also be possible to squeeze a brief case behind the seats.
Larger items can be stored in the rear boot, which is situated behind the
engine cover. The rear boot has decent width and depth but it is relatively
short front-to-rear. The spare wheel is usually mounted in the front
under-bonnet area - as seen here. This area can also accept some decent size
cargo.
Cosmetically, the AW11 MR2 is blatantly ‘80s but it’s certainly unique - we
like it. The supercharged model is identified by the raised vents on the engine
cover. Fourteen inch alloy wheels and 185/60 tyres come standard.
Potential for modification is huge. The 4A-GZE is a very strong engine
featuring block ribbing, a heavy-duty head gasket, a water-to-oil cooler, forged
pistons and oil jets to cool the piston skirts.
One of the first mods we suggest is an upgrade intercooler. The factory unit
is relatively cheaply manufactured and its air-to-air core functions as an
interheater in traffic conditions. It’s possible to maintain a cooler
charge-temperature by adding an electric fan to the underside of the stock
intercooler, but you might as well replace the whole set-up. A water-to-air
intercooler system works well on the MR2. (A second-hand Subaru Liberty/Legacy
RS heat exchanger would be ideal.)
Next, it’s time to open intake and exhaust flow.
As seen in this photo, the standard airbox is tucked into the left side of
the rear cargo area. A cylindrical K&N filter with a cold air feed is a
proven upgrade.
The exhaust of the MR2 is relatively short, but – depending on the path you
adopt – there is a number of tight radius bends. A 2 ½ or 3 inch exhaust is
ideal and be sure to use quality, large body mufflers – these are essential to
keep the MR2 quiet.
The next upgrade should be an aftermarket pulley replacement to increase
boost pressure. It may also be possible to upgrade to the larger displacement
supercharger used on the Toyota1G-GZE engine.
Oh, and the ultimate development is a so-called twin-charger set-up where you
use a supercharger and bolt-on turbo kit!
And what about price? Well, the 1989 vehicle we tested was supplied by
Adelaide Japanese Imports and was stickered at AUD$12,000. The vehicle had
already been ADR’d, had 123,000km on the clock and came with the aftermarket
goodies mentioned earlier.
Replacement parts should be fairly easy to source since the AW11 was locally
delivered in atmo 4A-GE guise. The import wreckers are also full of 4A-GZE
engines and parts. Note that the AW11 MR2 Supercharged was also delivered to
North America, so parts and information (such as service
manuals) are readily available.
Yes, this really is one of the most attractive import options. If you don’t
need more than two seats, check ‘em out!
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