NISMO & Z1 Motorsports 370Z Time Attack #23 Project

The Z1 Motorsports time attack 370Z was purposefully built to meet “GTA Limited Class” regulations featuring the industries best offerings coupled with custom-built components & extensive system integrations.

The story for our Z build begins as a rise from the ashes of sorts from former Z racer & IMSA team owner: Tim Bell. Tim and his race team’s spare chassis started life as a new 2010 model purchased from a dealer’s lot. It was stripped, and acid dipped before being put onto a rotisserie for their build. When the racing support slowed, unfortunately, so did the need to build out the spare chassis. Neglected, it sat for years. Knowing this, Z1 opted to call on a friend when it came time to source a chassis dedicated to racing. Tim’s team, now at Old Spool Performance, installed a Z1 spec’d chromoly cage prior to Z1 taking delivery of the chassis.

Upon delivery, Z1’s team immediately went to work putting the already bare tub on a diet. Unnecessary parts of the chassis were removed to reduce weight. The engine bay was 3-D scanned for the build, and modifications for cooling, servicing, and aero were made ahead of the first round of paint (cage & interior). While the Z was away progress would continue...

A 3.5L HR engine from a Hybrid Q50 was sourced as the donor for the build. With a unique cylinder head & all hydraulic cam phase control the pistons and cams would need a custom touch. Z1 provided specs from the head & cam choice along with 3D scans & a combustion chamber mold to Diamond Pistons. A week later the pistons were paired with a 3.7L crank and BC connecting rods. Heads were heavily ported & relief cut for the Jim Wolf Technology C9 and custom indexed RZ1 cams. Final assembly was completed with matched JWT valve springs. Top and bottom end bound with ARP fasteners.

The drivetrain includes a sequential transmission paired with a racing clutch tough enough to hold the power, nothing off the shelf would do so collaborative work would be needed. Tilton engineering was chosen for the Clutch & Flywheel package; while HGT precision would help develop and supply the transmission on the short timeline. Luckily, the NISMO GT PRO differential was readily available and would be built into a heavy-duty housing. A NISMO Differential Cover and NISMO Differential Cooler were added to manage differential temps.

When the car returned from the first round of paint, it was removed from the rotisserie and outfitted with an aluminum rear subframe conversion - featuring NISMO bushings, Nismo camber, Nismo traction & Nismo toe arms. The front subframe was installed with the engine and custom Z1 motor mounts to move the engine slightly rearward. Front suspension was appointed with GTR knuckles & hubs. Front adjustments come thanks to Nismo Front Upper Control Arms & Nismo Outer Tie Rod Ends. Each corner was upgraded to M14 Nismo extended studs then outfitted with a GTR Brembo Brake kit. The car is suspended above a custom set of BC ZR 3-way coilovers on Swift Springs.

As the build progressed, it would have to do so on a temporary set of Mag Blue Volk TE-37’s & Yokohama AD08 tires, the desired Rays Volk ZE-40 wheels & Yokohama Advan A052 tires had not yet arrived from Japan. Titanium lug nuts keep the rolling stock secure.

The front frame structure ahead of the shock towers were clipped so a custom “V Mount” setup could be installed to manage needed cooling and aero requirements. Housed on the new structure would be a modified Nismo Radiator (to dual-pass) and a set of light weight tube & fin HKS GTR intercoolers & HKS Racing SQV blow off valves. Piping for charge air and intakes were fabricated along with a custom swirl pot to make bleeding the Z a breeze. The additional capacity and air separation are always welcomed when trying to cool a boosted VQ. At this point the powerplant was removed and the rolling chassis returned to paint for the exterior work.

When the car returned, the power plant and powertrain were married and installed into the chassis. The front support structure was reinstalled with all piping, coolers & ducting. The aluminum hood was modified to exhaust heat from the intercoolers.

The updated long block received Z1 Ported Upper & Lower plenums to feed the engine before exhaust gasses are expelled through CJ Motorsports turbo manifolds to a pair of GTX3076 turbos nestled in Tial GT30 turbine housings. Boost is managed by a set of Tial MV-S wastegates and HKS EVC VI IR 2.4 boost controller. Exhaust is sent downstream by a set of Z1 Race Down Pipes & a custom Z1 side exit race exhaust.

A CJ Motorsports pump assembly houses dual Aeromotive 340 LPH pumps supplying 1700cc Injector Dynamics fuel injectors in CJM rails. Fuel flows via custom Z1 fuel lines to an Aeromotive regulator before returning to the custom half tank.

A reworked EFI harness & custom-built body harness connect an ECU Master Power Management Unit (PMU) & ECU Master Advanced Display Unit (ADU) to network all control and logging of the vehicle. High & low speed CAN networks allow for complete data logging and harmonious operation between the engine, Bosh M5 ABS, cooling systems and display. Everything from engine sensors, tire temperature & pressure, GPS, numerous additional temperature and pressure sensors; even the current on many components is monitored by the PMU & ADU. The OEM TPMS & Steering Angle Sensors were retained and logged all in real time.

This electronics setup offers not only control, but a complete snapshot of how each system of the car is performing at any specific part of the track. The data can be pulled via a hot-swap of the USB drive during any pit stop from the dash-mounted quick data access panel. This custom location (under the passenger side of the dash) offers quick access to the factory Data Link Connector, with direct access to either CAN network should the need to troubleshoot arise.

Inside the cockpit it is all business, the driver is housed safely in an OMP HRC-R Carbon Air seat, safely restrained by a NISMO 6 pt harness. All controls are driver focused and purpose driven. A Tilton Engineering Pedal set handles all hydraulic and throttle duties, while a remote bias control allows for fine tuning of the binders. The ECU master display offers everything the driver needs from gear position and engine speed, to out of limit warnings for any system on the car. The Bosch M5 ABS selector dial and 12 position ECU Master keypad allow quick access to any control while at work behind the OMP Carbon S steering wheel.

In pursuit of faster corner speeds Z1 has begun development of a comprehensive aero package to compliment the 2020 NISMO body work. A 3-D scanned original front splitter with diffuser helps with up-front dividing of airflow, as well as speeding up airflow under the car. All the while a pair of APR carbon side splitters help to maintain division of undercar low pressure and outer car high pressure air. Just after the rear axle air enters the massive Z1 Diffuser, reduced drag and improved downforce are complimented by the massive APR GT1000 dual element wing.

Fun Facts

3D printed parts:
• Center console control panel & center vent panels
• Shaved Dash Inserts (gauge plugs)
• Shroud & Mount for the ADU
• Steering Angle sensor adapter
• Tire Infrared Camera Mounts
• Brake Ducts
• DRL Ducts
• Door Pull Mounts
• Com Port Mount
• Prototyped – Engine Mt Brackets, PS relocation, Trans Mount, Shifter mount, numerous metal bracket templates.

Stay tuned for further build details!