Body
& Soul
With its Muscular Silhouette and
Gleaming Rotary Power could this be The Ultimate RX-7?
Text By Evan Griffey
Photos By Henry DeKuyper
Being impressive means making an impression. Whether you
are a fan of performance or aesthetics, making an impression
comes down to the fine details. Paying attention to the
details and being precise and deliberate about the building
and tuning of an engine can be the difference between
respectable power and a ground-breaking performance.
Style-wise, checking the fine print when addressing paint
and polish as well as dreaming up modifications and
treatments that have rarely, if ever, been seen help elevate
status. A problem with such intense concentration is that it
can lead to tunnel vision where a single aspect is
scrutinized exclusively. Performance dominates and style
doesn't even get a second or third thought, or style is
prevalent, but there is nothing under the hood but road
dust. True visionaries are able to focus on all aspects
while keeping their quality standards high. There are less
than a dozen of these elite tuner/fabricators out there and
Alex Chen of SP Engineering is definitely part of the club.
Over the past two or three years, we have featured many of
his creations in these pages. Including Andrew Chu's wicked
RX-7, he has landed two covers in 2001 and this is only the
eighth issue. Why is this? His street cars make big power
while looking like museum pieces.
It is a given that one cannot be an expert at everything.
This is true with Chen. When it comes to bodywork, he finds
someone with similar high standards. He has a few avenues to
pursue, but for the RX-7, he enlisted the skills of Kevin
Blakely. Blakely had a hill to climb; the Mazda was slated
to wear crazy eye-popping R.E. Amemiya flared body armor.
The kit was so finely molded onto the car, it looked like
sheetmetal stamped at the factory. The transitions between
kit and car are seamless and the wild Lambo orange paint was
applied so carefully it looks like the Mazda is still wet.
The Mazda's sparkling 13B illustrates that the engine bay
is where Alex and SP are most at home. The list of polished
pieces is a long one with some of the more notables being
the radiator and mounting bracket, GReddy intake plenum,
piping, alternator, catch cans, turbo shield and, of course,
the twin turbo system. The weapon of choice is a package
featuring twin 2835R GT series turbos with .61 A/R
compressor housings and 56-trim compressor wheels. HKS
Racing wastegates and a Blitz i-D SBC controller rope in
boost to a conservative 19 psi. A custom 3.25-inch SP
downpipe ensures the turbos can spool to their heart's
content, while a Blitz front-mount intercooler puts the
chill on the charge.
Fuel enrichment is handled by a Cosmo in-tank pump, -6
Earl's lines, a custom fuel rail and SX regulator. The
staged fuel injection set-up consists of 850cc primaries
backed by two 720cc secondaries, all controlled by a HKS AIC.
The stock ECU is still the main engine management component,
but it has been ROM-tuned by SP Engineering for maximum
efficiency. On the spark side, an HKS Twin Power amplifier
boosts current to a set of NGK plugs by way of Ultra wires.
SP's Jason Reinholdt grafted the fuel and ignition
components into place.
Power meets pavement through the stock Mazda gearbox, an
O.S. Giken clutch and flywheel combination, a carbon fiber
driveshaft and a trick Japan-spec R.E. Amemiya rear-end with
a 3.73:1 gear ratio. G-forces are subdued by a Tein
coil-over system. Tein Circuit Master RA Type suspension
system. The Tein system consists of four shocks, four main
springs, four helper springs, spacer spring seats, thrust
washers, bumper cushions, dust boots, upper pillow ball
mounts, height measuring gauge and damping adjustment tool.
The dampers are aluminum bodied mono-tube designs that
utilize large diameter piston rods and big piston valves and
feature 16 points of adjustment. Racing Beat bars add
further stabilization to the suspension, which sees a good
deal of g-load when the proper conditions present
themselves. Brembo four-piston calipers put the bite on big
drilled rotors, enhancing Chu's confidence when heading into
a hairy apex or panic stopping in traffic. With the
labor-intensive body tuning performed on the Mazda, upgraded
brakes are excellent insurance policies.
Chu's RX-7 will be tuned as a driver delivering its power
at a conservative 19-psi. Since Chu was out of the country
when this article went together and the Mazda's registration
lapsed in the interim, the engine could not be properly
broken in. As a result we have no dyno charts to illustrate
the the car's bottom-line power. If things line up properly
we hope to bring you the tuning portion of the story at
turbomagazine.com.
The orange hue of this Mazda is loud, so is its 13B at
full song, but the RX-7 really screams of craftsmanship and,
like our duo of old schoolers on last month's cover, this
rotary flexes upper echelon craftsmanship in spades.
Text and photos courtesy of Turbo
Magazine |