Supra Twin Turbo - a cheap way to go fast
The first Toyota Supra's appeared in Japan in 1978, and production
continued until 2002, with the car undergoing three major revisions
culminating in the Mk IV twin turbo Toyota Supra of 1993 - 2002.
The Mark IV Toyota Supra was offered with two different engine
options; a naturally
aspirated 2JZ-GE, 3.0 litre, straight 6 with 220 horsepower
and 210 ft/lbs of torque, and a 2JZ-GTE 3.0 litre twin turbocharged
straight 6 with 320 horsepower and 315 ft/lbs of torque.
For many, part of the twin turbo Toyota Supra's attraction comes
from the easily upgraded power output. 450 - 500 horsepower
can be had out of the stock turbos with a free flowing intake
and exhaust system coupled with an aftermarket boost controller.
The MKIV Supra's turbochargers operate in a sequential format
where, at first, all of the exhaust gasses are routed to the
first turbine for reduced lag. This results in increased boost
and enhanced torque as low as 1800 rpm. Approaching 4000 rpm,
the exhaust gasses are routed to the second turbine for a "pre-boost"
mode, although none of the compressor output is used by the
engine at this point. Around 4500 rpm, the second turbo's output
is added to the intake air, and both turbos operate in parallel.
The sequential operation of the Toyota Supra's turbos allow
for improved low-end response.
The Mark IV Toyota Supra, although no featherweight, was extensively
lightened compared to the previous generation. The use of aluminium
for the hood, targa top, front crossmember, oil pan, and upper
A-arms helped. As did dished out head bolts, a magnesium steering wheel, plastic petrol cover, and a gas injected rear spoiler.
Despite having more features such as dual airbags, traction
control, larger brakes, larger wheels, and larger tires,
the MK IV Supra was at least 45 kgs (100 lbs) lighter than the
External review by AJI:
The MKiv Toyota Supra saw an extensive weight reduction diet
over the previous version of this model. At a time when Supercars
were being produced left right and centre, Toyota decided to
get in on the act with the MKiv. Honda had already realeased
the NSX and Nissan with the Skyline and the 300ZX, and with
Europe and its choices of British, Italian and German high performance
cars the Supra was fitted with a twin turbo setup and the export
version hit the market with 326bhp as standard.
The export version of the Supra was the highest specification
version of the Supra, this is strange as the Japanese home market
versions are usually this way. So therefore this saw the export
versions fitted with stronger steel turbos, bigger brakes, bigger
fuel injectors, glass headlights, full leather interior, and
generally more 'toys'. They were all twin turbos and came in
either 6-speed manual or 4-speed automatic. The export MKiv
was generally over engineered, it therefore produces a car that
can easily be tuned to the 450-500bhp area without the need
to upgrade vital internal parts. The getrag 6-speed gearbox
is a good strong unit and the 6-cylinder
engine is a racey unit with plenty of torque.
The export Supras were tested and produced a 4.9sec time to
get to 60mph. The top speed of the export versions is 180mph,
and 6th gear if it were allowed would result in a top speed
of 196mph if the car had the power to get there.
The Japanese home market versions of the Supra came with a large
tick-box on the specification lists. But the two main models
were the RZ (the twin turbo) or the SZ (the normal aspirated
version). Later in the production line the GZ was released which
was basically an RZ with all the extras ticked. And later still
the Japanese home market version went through a facelift giving
it the bigger brakes and other details which included a modification
to the front bumper.
The engines between the J-spec and the export version has some
considerably differences. The turbos were ceramic as opposed
to steel, the fuel injectors were smaller and although the torque
figure was still very coparable to the export version the bhp
figure was slightly down.
The J-specs had a top speed of 170mph due to the slightly lower
bhp figure. And, they got to 60mph in 5.1sec. The automatic
versions always had slightly worse performance figures due to
the power loss through the transmission, but the auto box is
still considered one of the best on the market.
The Euro-spec version of the export model saw the inclusion
of a bonnet vent to aid cooling to cylinders
3 and 6, the Japanese home market and US export version never
had a bonnet vent. Some home market Supras appeared with no
rear spoiler, this is down to the tick-boxes on the spec. list.
|Year (of specifications)
|| 1993 - 2002
||3.0 litre in-line 6 cyl twin turbo
||6-speed manual, 4 auto, RWD
|| 5.1 seconds
|| 326 hp @ 5600 rpm
||1565 kg / 3450 lbs