Mega-morphosis
410 whp Silvia-Powered 240SX
Text by: Evan Griffey
Photos by: Henry DeKuyper
Japanese manufacturers are sadistic. It's as simple as
that. The japanese market gets the good stuff and we always
get teased. Case in point--the Nissan 240SX. We get the
handling prowess and body shape of the JDM Nissan Silvia, but
under the hood lies the innocuous KA24DE engine, generating an
anemic 155 hp, while the Silvia flexes 217 beefy turbo hp from
the delectable SR20DET in '95 vintage S14 trim. The bottom
line: We get rocked by 62 hp; not to mention the loss of
potential.
The big get even? The SR20DET swaps into the 240 with ease
and the hearty four-banger loves aftermarket attention.
Jonathan Yeh of Chino, Calif. wanted to invigorate his 1995
Nissan 240SX with the famed swap. The big challenge is wiring.
A quick way around this is buying a complete Silvia front
clip, which includes ECU, harness and some key body parts to
complete the Silvia transformation outside of the engine bay.
Yeh, who went the engine-only route, enlisted SP
Engineering to install an S13-spec SR20DET. The engine dropped
right in with the help of Nismo S14 solid engine mounts. The
wiring nightmare was sorted out with a Japanese service manual
and trial-and-error, but everything in the car works as it
should. The swap was performed in early 2000 and Yeh was
content running the stock SR20DET with its T25 turbo at an
elevated boost of 14 psi (stock is 10 psi).
In early 2002, the call for more power echoed and Yeh was
ready to step past stock. SP Engineering technicians Rex Kieu
and Jason Reinholdt pulled the engine and fitted the bottom
end with goods from GReddy. A set of 1mm oversized pistons
with a boost-friendly 8.5:1 compression ratio were joined by
forged GReddy GRex series rods and rod bolts. A tricky aspect
of the swap can be clearance under the car so SP installed a
GReddy oil pan, which has a lower profile than the stocker.
With the engine out, the cylinder head was given a splash of
attention. GReddy springs were swapped in for increased
revving ability and a set of GReddy 264-degree cams went in to
maximize power at elevated engine speeds. A pair of adjustable
cam gears is on-call to fine-tune the power curve.
The hard parts on the SR20DET were fortified to support the
extra pressure created by a wicked GReddy T78 turbo upgrade.
On this 2.0-liter, a T78 represents an inter-dimensional leap
from the small, stock T25. The big hairdryer is mounted on a
GReddy manifold and charge air is chilled by a GReddy R-SPL
intercooler tucked seductively behind the Bomex front spoiler.
To support the added boost on the fuel side of the
equation, SP installed a high-flow HKS fuel pump, SARD
regulator and Nismo 660cc injectors. Fuel and ignition events
are controlled by a ROM-tuned stock Silvia ECU. SP
Engineering's Shawn Wang, formerly of G-Force fame, was in
charge of programming the ECU to idle and make power with the
bigger injectors and the SR20's dramatically increased air
volume.
The T78-pressurized, fully built SR20DET was ROM-tuned on
SP's dyno. In accordance with the ROM tuning, an HKS VPC and
EVC IV were used to pump the power to the wheels. A shakedown
run at 0.9 Bar netted 335 hp; that's a pretty good place to
start. A sticky wastegate kept boost levels down, but once
fixed, pressure was raised to 1.3 Bar. The stout SR20DET
responded with a tally of 410.1 whp.
Now that the 240 now has the soul of a Silvia, what about
the facade? Sure, swapping Silvia emblems a la the JDM craze
is easy (and expensive) but you get a stock-looking car. Yeh
went the J-Spec route and added a Silvia body kit from Bomex.
The bodylines of the 240 and the Silvia are identical, so the
Japan-market Bomex front clip, side skirts, grille and rear
fascia fit perfectly. To push styling one step further, Yeh
added a Bomex hood spoiler and trick Bomex mirrors. The
spoiler mounts on the leading edge of the hood and adds a
one-off flair to the car while side mirrors tuck close to the
body. The Bomex body armor was expertly installed and sprayed
with eye-catching Volvo saffron paint by 20/20 Autobody in
City of Industry, Calif.
Suspension mods were limited but effective. Koni adjustable
shocks and Sheep Dog springs, Nismo strut tower bars and Cusco
anti-roll bars smooth the road and counter the g-forces during
spirited driving. Rolling stock consists of Kinesis K20
aluminum and Falken ZE-502 performance rubber. At the nose,
17x9 K20s are joined by 235/45R-17s while the rear set-up runs
17x10 rims are wrapped with 255/40R-17s.
It's always wise to be able to get out of trouble quicker
than you get into it. Yeh addressed this axiom with 300ZX
Twin-Turbo stopping power. The front brake conversion uses the
300ZX hub/rotor assembly and caliper. SP custom-mounted the
calipers and fabricated stainless-steel braided lines to
complete the operation.
Yeh bought this car brand new in 1995, so he knows better
than anyone how dramatically the performance of the Nissan has
evolved. Going from 144 hp at the flywheel to 410 at the drive
wheels must be a mind-altering experience indeed. There's one
problem. We hear the Nissan is driven two to three times a
week. Jonathan, there are seven days in a week--use them...
Text and photos courtesy of Turbo
Magazine |
