Introduction

The EcuTek boost control code is based on the proven strategy used starting with GT-R RaceROM Phase 6. We recommend tuners use RaceROM boost control as it now has its own full set of dedicated maps so you no longer have to create a large number of custom maps. Upon adding a RaceROM patch with this code in it, this option is enabled by a simple check box, and comes pre-populated with some sensible values that should allow reasonable levels of control after a little tuning.

This is a general overview of how the system works, there may be some differences (more or less tables, limitations etc.) for your exact vehicle.  These should be outlined in the RaceROM Supplement for your particular platform.

Absolute Boost 

Boost control uses Manifold Absolute Pressure throughout. Please ensure you are familiar with the concept of the absolute pressure before tuning the boost control. Remember that a target of 1.0 is close to sea-level atmospheric pressure and not positive boost.

• Boost Error – Difference between MAP and Boost Target, positive numbers are over boost

• Boost Target – Absolute pressure target in bar, measured by the intake manifold pressure sensor

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

• Wastegate Duty – The duty cycle applied to the wastegate solenoid (Same as Final Duty)

• WG Duty Base – Output from Wastegate Duty Base maps

• WG Duty Adder – Correction resulting from Gear/IAT multiplier step

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

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

Additional Guides

• RaceROM Custom Maps Tuning Guide

• RaceRom Map Switching

• RaceROM - Flex Fuel

RaceROM Boost Control

We now have boost control hardcoded into the RaceROM files so you won't need to make custom maps to control forced induction.  This is done entirely by the factory ecu utilising the CPC control valve. You can now set up and tune boost control with a large degree of freedom and control allowing you to safely achieve the power boost available from forced induction. 

Enabling RaceROM Boost Control

To enable RaceROM boost control it's just a simple toggle that (on most platforms) changes your CPC signal over from factory behaviour to the boost control maps.

CPC Output Hijack Frequency

When using Boost control (and custom maps CPC output) the OEM functionality is completely overwritten by this function and the valve is driven at this set frequency.  On some vehicles this frequency isn't capable of being adjusted due to limitations of the ecu.

Boost MAP Control Smoothing

The output of the MAP sensor can be smoothed for the purposes of boost control. 0 is maximum smoothing 1 is no smoothing.

Tuning RaceROM Boost Control

To properly tune the boost control system you'll want to start by setting sensible limits and targets first to ensure that the boost control maintains sensible and safe levels as you slowly ramp things up.  From there you'll start dialling in the wastegate closed loop behaviour as needed in order to hit your targets.

Basic Operation of Boost Control System

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Map List

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Live Data Parameters

• 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

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

• WG Final Duty – The duty cycle applied to the wastegate solenoid (Same as Final Duty)

• WG Duty Base – Output from Wastegate Duty Base maps

• WG Duty Adder – Correction resulting from Gear/IAT multiplier step

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

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

Boost Limits

The Boost Limit function is integrated with the flex fuel systems the system works as shown in the diagram below.  When a limit is exceeded a fuel cut will cut fuel to all cylinders.

Boost Limit - Gasoline

The manifold absolute pressure needs to exceed final blend between this limit and Boost Limit -Ethanol, measured in Bar by the manifold pressure sensor, for a time that exceeds Boost Limit Delay, to trigger an fuel Cut as an overboost safety measure

Boost Limit - Ethanol

When running maximum ethanol content scaled in the blend map the manifold absolute pressure needs to exceed this limit at Maximum ethanol blend, measured in Bar (relative) by the manifold pressure sensor, for a time that exceeds Boost Limit Delay, to trigger a Fuel Cut as an overboost safety measure.

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Boost Limit -Flex Fuel Blend

The manifold absolute pressure needs to exceed this limit, measured in Bar (relative) by the manifold pressure sensor, for a time that exceeds Boost Limit Delay, to trigger an Accel Cut as an overboost safety measure

Boost Limit Delay

Time period in milliseconds the ECU will wait before triggering the boost limit fuel cut when the manifold relative pressure exceeds the boost limit as set by the final boost limit value blended between Boost l Cut.

Boost Limit Hysteresis

With the default limit of 2Bar and hysteresis of 0.4Bar, the fuel will be cut when the MAP exceeds 2Bar for 0.3 seconds and resume when the MAP drops below 1.6Bar.