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J-Spec and Export-Spec 2JZ-GTE Differences

There are certain differences between the 2JZ-GTE engines destined for the Japanese Domestic Market and the North-American and European Market.

J-SpecExport-SpecImpact
Engine Peripherals
Controlless aggressive intake camshaftmore aggressive intake camshaftLess aggressive camshafts allow the engine to respond faster.
Duration224°233°
Valve Lift7.88mm8.25mm
InjectorsHigh Impedance and weaker fuel pumpLow Impedance with series resistorWhile increasing boost the smaller injectors cause the engine to run lean earlier. Many third-party ECUs won’t work with high-impedance injectors.
Flow Rate440cm³550cm³
Air-Flow SensorManifold Absolute PressureManifold Air Flow
Exhaust Gas RecirculationNonEGR availableAn EGR causes lower combustion temperatures and soot deposition in the intake manifold. Without an EGR problems at smog-testing may occur caused by too high NOx-Emissions.
Turbo System
TurbochargerCT12bCT12bThe ceramic turbine is more fragile. It can withstand boost up to 1.2 bar, while the steel turbine can stand up to 1.6 bar. On the other hand ceramic turbines are more responisve.
Turbine DiameterInlet/Outlet 60/48mmInlet/Outlet 52/44mm
Turbine MaterialCeramicSteel
Compressor DiameterInlet/Outlet 62/39mmInlet/Outlet 58/39mm
WastegateweakerRemoving the first catalyzer in the downpipe can cause boost spikes. The wastegate used in the J-Spec needs resistance in the downpipe, e.g. a sports catalyzer or a restrictor ring.
Electronics
Traction Control (TRC)mechanicalAdditional intervention in ABS-System via TRAC-PumpThe J-Spec Traction Control does only react on straight roads.
Speed LimiterFuel Cut at 180kph (112mph)Closing the TRAC-Butterfly Valve at 250kph (155mph)On export vehicles pulling the TRAC-Fuse is enough to delimit the vehicle (don’t do this on Automatic vehicles, it will cause gearbox failures). J-Spec vehicles need a Speed Limit Defender (e.g. HKS or Trust/Greddy).

Comparison of J-Spec and Export-Spec Performance Curves

The graphs above show the J-Spec’s and the Export-Spec’s official torque and power curves measured according to DIN-Standards.
The J-Spec’s torque-curve (red) is quicker rising then the Export-Spec’s curve (blue) as a result of the ceramic turbines’ better spooling characteristics.
The blue J-Spec curve peaks at 3600 rpm pushing 431Nm.
The red Export-Spec torque-curve peaks at 1200rpm later, but with a higher output of 441Nm. Those characteristics are caused by the Export-Spec’s inlet camshaft. Inlet Valves close at 50° ABDC, 9° later then in the J-Spec version.
The J-Spec’s torque-curve starts to artificially go down after the peak at 3600rpm. This is due to the Gentlemen Agreement not allowing a power output higher then 280hp. You can notice this by looking at the green J-Spec power curve.

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