The VQ35HR that equipped the 2007-8 350Z featured a number of changes that required development of a new twin-turbo system. The main difference from previous VQ35 engines, the dual-path intake system, features separate throttle bodies for each bank of cylinders. This would require a different intercooler and hard pipe setup. GReddy began with a tuner approach to the system. A pair of GReddy cast ductile-iron manifolds supply high-enthalpy exhaust gasses to the turbine inlets of GReddy’s TD06SH-20G turbochargers. The turbos compress ambient air drawn through Airinx filters before channeling the aircharge through hard pipe to a dual-inlet, dual-outlet GReddy Type-29 R-Spec front- mount intercooler. Hard pipes make the connection from the intercooler to each of the throttle bodies.
VQ35 Invasion
The VQ35DE packed a knockout punch for tuning enthusiasts when it first hit the scene in 2002. Nissan’s CEO Carlos Ghosn consolidated Nissan’s engine designs and the VQ35 was the performance crown jewel, showing up in no less than six different platforms in various driveline layouts across Nissan’s product line. It has also enjoyed quite an evolution, with improvements that always included increased horsepower and technology. Since eight years have passed since the first VQ-powered platforms arrived in America, quite a few have found their way into junkyards across the country. Engines have become more readily available at a reasonable cost. Furthermore, the VQ has become a popular engine swap into the S-chassis (Nissan 240SX/Silvia S13 and S14) as well as the Z32 (300ZX). In drifting and drag racing, these older chassis’ equipped with VQ’s have been showing up at the tracks. A number of changes are required for the swap, but several tuners have already researched and designed kits to make the VQ swap a practically bolt-on affair. From welded crossmembers to transmission linkage adapters, wiring harnesses and driveshafts, powering a chassis with the VQ has become a viable consideration. Top that with an abundant amount of aftermarket support and the possibilities become limitless for the adventurous consumer seeking big power.
From The Crank To The Pavement
Generating more than triple the amount of torque at the wheels compared to stock puts atremendous load on the factory driveline. The factory clutch wasn’t engineered to handle the torque. GReddy turned to OS Giken for a clutch solution. OS Giken didn’t have an off-the-shelf unit available for this application, so an R3C triple-plate racing clutch with flywheel was developed for GReddy’s high-output Z. Now able to harness the power at the crankshaft, attention turned to putting that power down to the asphalt. A clutch-pack style, 1.5-way NISMO GT PRO limited-slip differential replaced the factory viscous LSD between the drive wheels. The power-robbing viscous LSD, which is fine for the average driver, is not as efficient as a mechanical LSD. A unique trait of the NISMO GT PRO is an adjustable initial-torque setting. Three different torque settings (6.5-, 8.5-, 14.0-kgf) are available and changes can be made easily by simply removing an axle and using a deep socket to change settings inside the axle port.
As the first components to make contact with the pavement, footwork and suspension could not be neglected. GReddy Type-S coilovers with electronic damper control add an aggressive stance to the Z. GReddy 10 kgf/mm springs up front and 8 kgf/mm springs in the rear provide the stiffness needed to keep the Volk Racing GT-F wheels and Nitto INVO tires pressed firmly to the ground. Not only do the springs plant the tires, they limit the suspension dive that the six-piston GReddy calipers cause during hard braking. The staggered wheel and tire combo are a complement to the GReddy GT AERO body kit. The GRACER kit (complete with overfenders, skirts, front bumper and rear bumper with diffuser) features aggressive yet complementary lines that do not actually increase the width of the body, enabling the use of the factory wheel offset.
Return or Returnless?
The two fuel delivery systems found in vehicles are classified as return and returnless. Many older vehicles came equipped with return-style fuel delivery systems, where the fuel rail contained an onboard fuel- pressure regulator (FPR); a fuel feed line and a fuel return line. This system contained more parts (return line and rail mounted FPR) and was considered mechanically inefficient because it would heat the fuel, but it could support performance improvements easily. In the early 2000’s, manufacturers began to adopt the returnless-style fuel system for its simplicity. The fuel pressure regulator was mounted in the tank and there was no return line plumbing to clutter or complicate the underpan of the chassis. These systems were engineered for the factory tune and thus provided plenty of fuel for the needs of the engine. However, when aiming for higher performance, the shortcomings of the returnless system become apparent. When using higher-flowing injectors, the system cannot meet the supply demands, leaving the injectors farthest from the point that fuel enters the rail dangerously lean. In the case of higher performance applications, it might be necessary to retrofit the fuel system with a return line and fuel pressure regulator. By making this change, each fuel injector receives ample fuel for the performance demands of the engine.
Pushing Limits
As one of the pioneers of VQ forced-induction kits, GReddy is aiming high for its big-displacement VQ35HR engine. Falling short of the 800 horsepower goal originally established for the build, the team is determined to attain and surpass their objective. Mike Chung of GReddy comments, “We were pleased to see 760 horsepower, but we know that we can hit 800 horsepower. We’re developing an intake manifold for the VQ that will replace the plastic unit from the factory. This new manifold won’t swell under high-boost conditions like the factory piece, which will help us reach the 800 horsepower mark.” GReddy maintained all of the amenities of a street car in this build while extracting nearly three-times the horsepower. But why stop with street competence? GReddy will be taking the Z33 to the track to fully explore the potential of the 4.2-liter VQ mill and the 350Z. From the quarter mile to the road race circuit, this former SEMA star is looking to make an impact wherever the rubber meets the pavement.
The two fuel delivery systems found in vehicles are classified as return and returnless. Many older vehicles came equipped with return-style fuel delivery systems, where the fuel rail contained an onboard fuel- pressure regulator (FPR); a fuel feed line and a fuel return line. This system contained more parts (return line and rail mounted FPR) and was considered mechanically inefficient because it would heat the fuel, but it could support performance improvements easily. In the early 2000’s, manufacturers began to adopt the returnless-style fuel system for its simplicity. The fuel pressure regulator was mounted in the tank and there was no return line plumbing to clutter or complicate the underpan of the chassis. These systems were engineered for the factory tune and thus provided plenty of fuel for the needs of the engine. However, when aiming for higher performance, the shortcomings of the returnless system become apparent. When using higher-flowing injectors, the system cannot meet the supply demands, leaving the injectors farthest from the point that fuel enters the rail dangerously lean. In the case of higher performance applications, it might be necessary to retrofit the fuel system with a return line and fuel pressure regulator. By making this change, each fuel injector receives ample fuel for the performance demands of the engine.
As one of the pioneers of VQ forced-induction kits, GReddy is aiming high for its big-displacement VQ35HR engine. Falling short of the 800 horsepower goal originally established for the build, the team is determined to attain and surpass their objective. Mike Chung of GReddy comments, “We were pleased to see 760 horsepower, but we know that we can hit 800 horsepower. We’re developing an intake manifold for the VQ that will replace the plastic unit from the factory. This new manifold won’t swell under high-boost conditions like the factory piece, which will help us reach the 800 horsepower mark.” GReddy maintained all of the amenities of a street car in this build while extracting nearly three-times the horsepower. But why stop with street competence? GReddy will be taking the Z33 to the track to fully explore the potential of the 4.2-liter VQ mill and the 350Z. From the quarter mile to the road race circuit, this former SEMA star is looking to make an impact wherever the rubber meets the pavement.