Our recommendation for the higher performance 640bhp Stage 4+ power levels is to switch to our new Version 8 Speed Density (SD) tuning. In standard form the ECU is only able to see the temperature from the MAF sensor at the intake filter which doesn’t reflect how the engine and the cooling systems are performing. Typically on tuned GT-Rs this temperature sensor has moved from the original thick plastic casing to a thinner aluminium intake which will see larger fluctuations in temperature that can affect the accuracy of the calibration.
Speed Density tuning moves the main ECU input from airflow at the MAF sensors and replaces it with pressure in the intake manifold. Not only does this give improved resolution but adds additional safety as we use the charge air temperature sensor to measure the heat that is actually entering the engine and correct it when it becomes too high. When populated correctly this detailed 3D map gives us additional control thanks to precise engine load calculations that help both power and drivability.
In addition to the main input to the ECU now using SD Density we can also use the charge air temperature to calculate/compensate for real time changes on actual air temp which results in a tighter boost control strategy, improved ignition timing and fuel corrections when under high or low temperature conditions.
Our SD kit includes a new genuine Nissan boost sensor with an in-built temperature sensor for OE reliability and uses a plug and play link lead to connect to the MAF sensor temperature input to the ECU. Both MAF sensors are retained and can still be used to log intake air flow for fault diagnostics and data acquisition. They are also available if the car needs to be reverted back to a standard in the future.