Modified Magazine's review of
the Nissan 350z Twin Turbo kit

The APS kit is made to be installed
with the motor in the car and is certainly a viable
endeavor with the right tools, a clean well ventilated
environment with a flat floor and quality jack
stands. Given our full compliment of lifts, engine
hoists and air tools, we strayed from these detailed
instructions by removing the engine and transmission
from the car. Having the VQ35 on an engine stand
while it undergoes its turbo metamorphosis definitely
gives you more room to work and saves a few knuckles
in the process.
After removing the front bumper and its support brace, disconnecting the battery
and draining the fluids, the core support and
radiator are removed. The resulting gaping mouth
allows easy removal of the soon-to-be-boosted
VQ35. Before the engine and transmission can be
removed the exhaust is disconnected at the catalytic
converters, the steering shaft is carefully marked
and disconnected and the main wiring harness is
disconnected. Once the shift lever is disconnected
from the transmission, the engine and transmission
are ready to be lifted out of the car as a unit.
After removing the transmission the engine is
bolted securely to an engine stand and the transformation
can begin.
Supplying air by turbocharging
APS uses two internally wastegated, water-cooled
Garrett twin ball bearing turbochargers to stuff
8.5 psi of boost into the VQ35at the stock settings.
However, APS claims these Garrett snails are capable
of 800 hp airflow capacity at 16 psi of boost
pressure with a fully built engine.
Of course, turbos are only as good as the plumbing
they are attached to. Exhaust gases that feed
each turbocharger must arrive at the turbine with
the maximum amount of gas energy in order to ensure
crisp response and power. The hot exhaust side
of this kit includes high flowing and high temperature-resistant
iron, cast exhaust manifolds and turbine outlets.
Keeping all that extra air cool before it hits
the combustion chambers is critical to making
power. APS has designed and manufactured a huge
25 x 9 x 3.5-inch core, custom configured, vertical
flow, high efficiency bar and plate style intercooler.
APS claims that the pressure drop is less than
1.0psi at 650 flywheel hp. At the same turbocharger
flow conditions, the intercooler outlet temperature
is less than 15°F higher than ambient at any
vehicle speed over 50mph.
Routing all this air into the intercooler and
then back to the turbos is a tricky proposition
in an engine bay that was not designed with twin
turbos in mind. However, APS pulls it off with
efficiency and style. Flexible air ducting connects
the intake filters to beautifully polished 304
stainless steel compressor inlet piping. These
equal length mandrel bent pipes connect the compressor
discharges to the twin intercooler inlets where
the air is chilled before being routed to the
throttle body by way of a custom-molded silicon
hose. On the way the chilled air passes through
the MAF sensor and any un-needed boost is vented
through the included APS high-volume, dual vent
blowoff valve.
Routing all the required piping necessitates
removal of the stock radiator overflow canister.
APS includes a trick stainless steel canister
as replacement for the molded plastic stock unit.
Heat shielding is critical in order to protect
the other components in the engine bay from the
heat generated by these turbos. APS includes moldable
stainless steel heat shields that will keep the
extra heat from damaging nearby components.
Be sure to give Autotech
Enginnering a call to see what they can do for
your 350z!
If you would like further informatio
on the APS Intercooled Twin Turbo System for the
Nissan 350z, please do not hesitate to contact
Autotech Engineering via email on sales@autotechengineering.com.au
or by phone
on (02)9897 1378