You go and get yourself a used NASCAR engine and use it in a street
car. As long as you do the regular maintenance, Keep it in tune, the
motor will practically last forever.  A modern built engine, using
today's chemicals, and advanced parts will last a long time under the
hood of your car.

That Supra's engine won't last any longer than any over turboed, over
bored, over priced foreign job out there.  The more hp you have, the
more it's going to break.  Just a fact.

                     ...Ron
--
68'RS Camaro
88'Formula
00'GT Mustang

My guess would be a very short stroke crankshaft.  HP being a function
of torque X RPM, you can get a high HP rating with relatively moderate
torque if you are twisting around 8,000 or 9,000 RPM.

You can blame this "phenomenon" on inertial dynamometers.
If this Supra really had 800 RWHP then these things would OWN the dragstrips
right?
You won't see more than a couple of theses super-boosted 4 cylinders at the
good old dragstrip and they don't fare too well.
The inertial dyno works by measuring the acceleration of the drum weights
under the wheels.
The idea is that a certain amount of horse power will accelerate the inertia
of the drums at a set rate. You can consider the crankshaft, transmission,
driveshaft, differential, axles and wheels to be "extra" weights that must
be accelerated in addition to the drums. Let's call this the car's
"drivetrain rolling inertia".
The dyno must "assume" this is a normal amount for a typical car.
This is the variable that makes the inertial dyno unable to measure true
horsepower.
Let's say you have two identical engines in cars with very different
drivetrain rolling inertia (think heavy wheels verses light wheels)
Remember, our identical engines produce exactly the same horsepower. The
setup with the heavy wheels will take about twice as long to accelerate the
drums. It will be measured to have about half the horsepower. The inertial
dyno operator will tell you that the purpose of the dyno is to measure if a
tuning change increased or decreased horsepower by comparing 2 runs by the
same setup, not to measure gross or even net horsepower.
Watch some video's of the twin turbo 1100 horsepower Supra running on the
dyno.
What you will notice is that it's over in about 3 seconds due to the very
small rolling inertia of the drivetrain not just the true horsepower of the
engine. It makes for some really outrageous bragging numbers that go well
with a lot of neon glow, a thumping audio system and 3 rear aero wings.
Next time a rice-rocket shows you his unbelievable dyno sheet,
take a look at his drive tires and ask somebody at the dragstrip how big of
a tire you need to put 800 "real" hp to the ground. One tire probably
wouldn't even fit in his trunk.