Whitehead Performance completed one of the 1st installs in Canada of the newly released AAM Twin Turbo Kit for 2009-2016 Nissan 370Z and 2008-2013 Infiniti G37 Coupe on a customer’s nearly new 2014 Nissan 370Z Convertible back in July of this year.
List of major upgrades and modifications in Part 1 of this 370Z Twin Turbo build:
- AAM 370Z Twin Turbo Kit
- Injector Dynamics 725cc ID Fuel Injectors
- Walbro 255lph Fuel Pump
- Osiris Uprev Tuning
- STILLEN Setrab Race Oil Cooler Kit
- ACT HDG6 Heavy Duty 6-Puck Sprung Hub Clutch Kit
- ACT StreetLite Lightweight SIngle Mass Flywheel
- Zspeed Metal Concentric Slave Cylinder/Release Bearing + S.S. Clutch Hose
- HKS HiPower S.S. Dual Catback Exhaust System
Stay tuned for Part 2 where Whitehead Performance makes some more modifications to improve reliability and add more control over all that power
The heart of the new AAM 370Z Twin Turbo Kit is the latest generation Borg Warner EFR twin-scroll ball-bearing turbos. These EFR turbos are amazing because they have quick spool like a small turbo and yet they flow large volumes of air like a large turbo for the big horsepower numbers.
In the 370Z, these turbos start making boost under 3000 RPM and make full boost at 3500 RPM while making power all the way to redline. Check out the torque plateau from full boost to 6500rpm on the dyno sheet. This car has instant power and response everywhere in the power band! Everyone was very pleased with the final numbers, the customer most of all! 578 whp and 500 wtq @ 10.5 psi are phenomenal numbers for a street 370Z on stock internals.
Installing the AAM 370Z Twin Turbo Kit is not for the average backyard wrench. The engine and transmission have to be dropped out of the car for installation. We found many hoses, pipes, connectors, wiring, a/c lines all had to be modified to make the kit function as intended but fortunately Whitehead Performance has the expertise to deal with these issues and foresee potential trouble and make the necessary corrections. We also heat wrapped many, many components including most fluid lines anticipating lots of heat and due to the tight space with the kit installed. Our suspicions were confirmed as underhood temps are so high that the factory wax undercoating started melting on the shock towers after initial shakedown testing!
Whitehead Performance opted for a AAM Twin Turbo Tuner Kit as we find that with our own fuel system choices and custom tuning, we get more power and better driveability than the off-the-shelf fuel and tuning that comes with the Complete kits. To that end we selected Injector Dynamics 725cc EV14 fuel injectors and a Walbro 255lph in-tank fuel pump which required some modifications to the factory fuel pump cage and worked perfectly afterwards. We then tuned the car with Uprev Osiris software on the dyno with the help of RS Tuning. The end result is excellent horsepower and torque and a car that is as driveable and reliable as a stock 370Z.
Whitehead Performance added a Stillen Setrab Race oil cooler kit to keep the oil temps in check. The VQ37VHR engine is notorious for running high oil temps stock and adding two turbos to the oiling and cooling needs requires a large oil cooler to keep the engine and turbos protected properly. The stock location for the Stillen Setrab oil cooler did not work with the AAM intercooler so we custom made new brackets to relocate the oil cooler in a better position. A specific oil filter was also required because of clearance issues around the oil lines.
Looking at the drivetrain it’s obvious the stock clutch and flywheel were never designed to handle double the stock horsepower. Whitehead Performance changed out the heavy dual-mass OEM flywheel for an ACT XACT Streetlite single mass flywheel that weighs a more moderate 17.4 lbs. Less weight = more transmission rattle at idle and in 1st gear so we prefer lightweight flywheels in the 16-20 lb range vs the 10-12 lb rangeA of the race lightweight flywheels. For clutch duties we installed an ACT HDG6 6-puck clutch kit. The clutch has the torque capacity to hold the turbo power while maintaining a moderate pedal effort and reasonable clutch engagement for street use. If the clutch ever needs a further upgrade, a NISMO Coppermix Twin Plate clutch would be the civilized solution.
Addressing a weakness inherent in the stock Nissan 370Z clutch system is upgrading the plastic concentric slave cylinder/release bearing inside the transmission. Whitehead Performance has had great success with the ZSpeed metal concentric slave cylinder/release bearing and s.s. clutch hose and we installed these parts while changing the clutch/flywheel. A new OEM master cylinder is usually required when changing the slave due to the poor design of this part. Replacing it ensures all the air can be bled from the system and results in a good consistent clutch pedal.
An HKS HiPower S.S. Dual Catback exhaust system was bolted to the AAM turbo downpipes. This high polished made-in-Japan stainless steel exhaust is one of the nicest systems on the market for Nissan 370Z and in this case provided a nice balance between a subtle low tone with no resonance or drone and the flow requirements of a twin turbo system. It makes beautiful music for the driver, especially with the top down!
The only giveaway that something is going on under the hood of this 370Z
A very tight squeeze around the steering knuckle. The starter solenoid had to be modified to make room for the turbo as well.
More modification work in this area in the next installment. Visible is the air filter, boost tube and factory MAF. This is a blow through system and the integrated BOV’s in the Borg Warner EFR twin scroll turbos are well upstream from the MAF’s so no stalling issues.
High quality cast stainless steel turbo manifold is one of the many features that set this AAM 370Z Twin Turbo Kit apart from the rest
Last but not least, we have two proud people: the happy owner in front and Marco leaning against a car – our employee who did all the fine work to make this project happen.
Video of the 370Z on some shakedown runs: