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VR30DDTT Boost Control

VR30DDTT Boost Control

Dec 16, 2022

 

ProECU Nissan/Infiniti VR30DDTT

v1.4

 

 

ProECU Tuning Manual Supplement: VR30DDTT Boost Control

 

 

 

Introduction

 

Starting with RaceROM Version 3, the OEM boost control has been rewritten and replaced with our own simplified boost control strategy using its own set of dedicated RaceROM maps. Upon adding a version 3 or later RRFF, this option is enabled by default, and comes pre-populated with a sensible stage 1 boost control setup. 

As the VR30 utilises electronic wastegates it is possible to set WG position at any RPM, the principles (proportional, integral and derivative) are the same as a pneumatic wastegate, however the control is performed in position rather than duty.  There are also turbo speed sensors in the 400hp (high boost pressure) model which adds another dimension to the amount of control the ECU can exert.

 

 

 

There are no blow off valves (BOV) as standard equipment on the VR30DDTT motors and as a result they are susceptible to pre-throttle over-boost during gearshifts or when entering overrun.  We have added some functionality to the boost control system in order to reduce the over boost amount, fortunately the system additionally is able to control MAP is relatively well using the throttle, further reducing the risk to engine internals. 

Table of Contents

Map List

Live Data Parameters

  • Boost Bank1/Boost Bank2 – Absolute pressure in bar, measured by the two boost sensors

  • RBC Maximum Desired Boost – Relative boost max target, matches number format on gauge

  • Boost Target – Absolute pressure target in bar, measured by the intake manifold pressure sensor Boost Error – Difference between MAP and Boost Target, positive numbers are over boost

  • Boost Target – RBC Maximum – The current RR boost controller setpoint.

  • Boost Target Multiplier – The QH0 based multiplier used for boost target correction

  • Manifold Gauge Pressure – “Boost” pressure measured in bar above the current atmospheric pressure

  • Manifold Absolute Pressure – Absolute pressure in bar, measured by the intake manifold pressure sensor

  • Manifold Pressure Sensor – MAP sensor voltage value

  • Turbo Speed B1 & B2– Current turbo speed in rpm only available on the 400hp models

  • Wastegate Actuator Position B1 & B2 – The mm distance the wastegate has extended (related to WG angle)

  • WG Actuator Position Sensor B1 & B2 – the WG position sensors current voltage output

  • WG Corr Base – Output from Wastegate Posn. Corr. Calculation, not used in RR boost control strategy

  • WG Corr Integral – WG duty added by Integral correction of EcuTek boost control strategy

  • WG Corr Proportional – WG duty added by Proportional correction of EcuTek boost control strategy

  • WG Corr - Prop Int Sum – Correction resulting from proportional and integral added together

  • WG Corr – Transient – Derivative component of boost error calculation

  • WG Offset – During Gearshift – Offset applied in mm during upshift.

  • WG Target – Air Temp Comp – Air temp correction value from target map (in Bar)

  • WG Target – Atmospheric Pressure Correction amount applied from the Atmo Pressure Comp map

  • WG target – Basemap Lookup - the value referenced in the WG target map (in mm)

  • WG Target – Position – Final Position target after all corrections (in mm)

 

 

 

EcuTek Boost Control vs RaceROM Boost Controller

There may be some confusion between the features for boost control in recent RaceROM versions, despite the similar naming due to historic reasons the two RaceROM features have different functions.

EcuTek Boost Control

EcuTek Boost Control is the control strategy to set the boost target and control the wastegate solenoid such that the boost reaches and remains on target.

RaceROM Boost Controller

(abbreviated to RBC) is a feature used to limit the boost target using ECU Connect and cruise control switchgear (when made available). The maximum boost target is displayed only in ECU connect or a ProECU log file. As can be determined from the boost target flow diagram the boost target can be below the value set by the RBC but it can never exceed it.

The RRBC is a final limit to any boost target, any boost target higher than the RRBC limit will be capped to the RRBC limit.

Note: If you are tuning on the dyno and not using ECU Connect to raise and lower the boost target set the Default and Max values to the same as your desired boost to avoid capping the target unintentionally.

RaceROM Boost Controller Default

Default value for adjustment of the RR boost controller value, this is used after programming or after battery reset etc.

RaceROM Boost Controller Maximum

Maximum limit for adjustment of the RR boost controller value, this is shown in ECU connect as well.

RaceROM Boost Controller Minimum

Minimum limit for adjustment of the RR boost controller value, this is shown in ECU connect as well.

 

 

 

 

 

Absolute Boost

As per the latest updates to GTR the VR30DDTT follows the use of Manifold Absolute Pressure (MAP) for all aspects of tuning the boost control. All boost target, boost limit and boost threshold values are all absolute values in Bar. Tuners will now find that all boost related maps and live data will give consistent readings regardless of altitude, and calculations will hold true in all circumstances.

To make tuning as simple as possible we have added the Boost Target -  Atmospheric Pressure Compensation maps by default, this gives a consistent “boost” at all altitudes, but the result is that your MAP will drop as a result, and power will be reduced at altitude if using the default Boost Target Atmospheric Compensation map

 

 

 

 

 

 

Electronic Wastegate Control

The VR30DDTT uses the latest technology for controlling the opening angle of the wastegates, the wastegate actuator is now electronically driven as opposed to pneumatically. The electric wastegate control actuator operates based on a signal from ECM and adjusts the turbocharger boost control valve angle via link rod. The electronic control allows the turbocharger wastegate control valve to be opened even in non-supercharging regions. This reduces pumping losses and contributes to the fuel economy. When boost is requested the wastegate valve angles are controlled by the electronic control with a high degree of accuracy but are currently limited to OEM WG setups.

 

The Key Principle with Electronic wastegates is that they are controlled by a target position as opposed to a duty cycle.  This extension is

  • 8mm equals fully extended / fully open wastegate (no boost)

  • 0mm equals fully protracted / fully closed wastegate (full boost)

There is a further lower level control for the actuator but these are not required currently as aftermarket WG controllers are not widely available.