|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.
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.