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Navigation: Advanced > Boost control

Boost control: Closed loop (advanced)

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Requires an output to be activated as Boost solenoid (closed loop)

 

 

Boost control (closed loop)

 

Boost control mode

Open loop (base table tuning) - No closed loop is active, used to first tune the open loop duty tables.

closed loop - Closed loop control is active.

closed loop (wastegate back pressure control) - Closed loop control is active as wastegate back pressure control.

Note: Always start by using the mode "Open loop (base table tuning)", DO NOT ACTIVATE CLOSED LOOP right away!

 

target tables

Specifies target tables.

 

target boost reference

Target map (above absolute vacuum) - Target is a given value, ex 250 = 1.5bar overboost pressure.

Boost pressure (above air pressure, sea level) - The target pressure is the amount of pressure to add above sea level ambient pressure (roughly constant power at different elevations)

Boost pressure (above air pressure, current baro) - The target pressure is the amount of pressure above current BARO pressure (constant amount of relative boost pressure).

 

 

boost ramp

Can be used to "slow down" the boost control to prevent overshooting as an example.

 

boost ramping

Specifies how the boost ramping (limitation) should be made.

Disabled - No closed loop is active, used to first tune the open loop duty tables.

Fixed - Closed loop control is active.

Gear based - Closed loop control is active.

table - Closed loop control is active.

 

ramp direction

Specifies which direction the limitation (ramp) feature is active on.

ramp both up and down - Will ramp both up and down.

ramp only up, instant down - This will limit the positive ramp and "snap back" to the correct target while on deceleration or liftoff. It can be used to make large turbo setups more forgiving, but if you lose grip at full boost and pedal, the target boost will only decrease at the same rate as the boost ramp..

 

Target boost ramp rate

Specifies the rate of the target boost to be increased/decreased, specified in kPa per second. Set to 0 for instant = no limit/ramp.

 

 

Activation

 

 

Activate above MAP

Specifies the MAP value where the control will be active, default 120kPa.

Note: Before MTune 1.145, the MAP value had to exceed 120kPa to actually pulse the output.

 

active above MAP mode

Specifies if the closed loop boost will be activated using absolute MAP (default) or the BARO corrected MAP.

 

 

 

How to tune closed loop boost

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1. Select mode "Open loop base table tuning".

 

 

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2. Change target boost table to as low boost as possible, here we have 200kPa as boost target at 100% throttle position.

 

 

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3. Adjust solenoid duty (%) to achieve the boost target entered in the target boost table, in this case 200kPa.

This value is used for the system to come close to target in the fastest way.

 

 

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4. Increase target boost table with a small amount. Move over to Open loop duty table and adjust duty to get

expected boost target. Do this until you are satisfied with different boost levels and their targets.

 

 

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5. Change mode to Closed loop. A few new options will be available. Change parameters accordingly to maintain a good

and stable boost pressure.

 

Note: Open loop duty table has fixed source axis and can not be changed!

 

 

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6. When all adjustments are done, you can alter the target boost table as you want.

 

Note: Source axis can always be changed here, right click on axis!