Custom Map Notes

Notes relating to each custom map can be added here. There is a 100 character limit. The “delete” key cannot be used as it’s still a hot-key for triggering live data, and the “Ctrl-S” hotkey combination doesn’t work for the moment so quit and click Yes on the Save Changes To Custom Map X dialog box to save your changes.

Deactivation Delay

Activation and deactivation now how independent delay times. This means you can trigger a custom map to be active immediately and it will remain on for a time even if the activation conditions are no longer met, for example a 10 second boost target increase.

Integral Min/Initial/Max

On our previous Custom Maps implementation the integral function would always start and default back to zero making multiplication via an integral impossible. An initial value of 1 will fix the issue.

How to set up Custom Maps Boost Control

By using custom maps it possible to rewrite the factory boost control system, this can be useful when tuning for larger turbo’s, stronger actuators and external wastegates.

You can set the wastegate duty as a fixed WG duty % for a target boost pressure, this is a very crude and basic open loop boost control system but it can be useful when setting up a heavily modified vehicle where there are a lot of variables at the start of the tuning.

Once the Ignition and Fuel calibration is dialled in then you can enable the proportional and integral compensations for the current ‘boost error’. This will create a fully closed loop boost control system.

If you wish to use the boost control in open loop then simply do not enable the proportional or integral maps or simply enable them in other modes (like Mode3 or Mode4) so you can see the affect they have on the WG duty.

The example below shows 3 custom maps configured for a custom boost control setup.

Map A is WG Duty for a Target Boost pressure

Map E is WG Duty Proportional addition for boost error

Map F is WG Duty Integral addition for boost error

The current Target Boost pressure is output of the 3d ‘Target Boost’ map, the RaceROM Boost Controller (RRBC) is then considered.

The current target boost is always the lowest boost target value, so if the output of the 3d ‘Target Boost’ map is 1.2bar but the RRBC setting is 0.9bar then the Target Boost Pressure is 0.9bar and this will be the X axis input value for Map A.

But if the current RRBC setting is 1.4bar then the Target Boost Pressure would be 1.2bar.

You can see and log the current Target Boost value shown under Live Data.

. Custom Map A – Wastegate Duty for a Target Boost Pressure

• X axis is Target Boost Pressure (bar)
• Y axis is Engine Speed (rpm)
• Map values are Wastegate Duty (%)

The map output will be the Wastegate Duty% for the current Target Boost pressure.

This will overwrite the factory WG duty control.

In this example below at 3400rpm and 1.2bar Boost Target the WG Duty will be 65%. 

Calibrating the base Wastegate Duty using Custom Map A

Using RRBC its very easy to calibrate and create a base WG Duty Map A profile using the following tequnique but ensure no proportional or Integral maps are enabled. 

Fill Map A columns with 0 to 100% values like shown to the left then make a few power runs starting at 0.7bar and increse the RRBC in 0.1bar incremements and log the results. You can now see what boost pressure is created for a given WG Duty. 

So if 20% WG Duty makes 0.9bar then enter 0.9 in the X axis column above the 20% column. If 40% produces 1.1bar and 60% produces 1.3bar then simply enter the boost value in the X axis above the corresponding WG Duty column.  

Custom Map E - Wastegate Duty Proportional Control

• X axis is the current boost error (Bar)
• Y axis is Engine Speed (RPM)
• Map values are Wastegate Duty proportional compensation factor.

Custom Map E will add the map output value to the current WG Duty (output of Map A) for a given RPM and Boost Error.

In the example shown below the X axis is boost error (the difference between the Target Boost and Manifold Relative Pressure MRP). The Y axis is Engine Speed.

In this example above at 3200rpm and -0.375bar boost error (so under the boost target) Map E will ADD a value of 26 to the current WG Duty therefore increasing the WG Duty. 

Assuming the current value for Map A to be 65 then the WG duty will increase to 91 (65 + 26) to give a final WG Duty of 91%. 

As the boost (MRP) increases and nears the boost target then the size of proportional value added will decrease accordingly and as the Boost Target is achieved the proportional amount added will be zero. 

If the boost overshoots the target boost value then Map E will REMOVE WG Duty as well.

NOTE: The Proportional value (output of map A) is a one time only added addition and it does not accumulate like an Integral value will do.

Calibrating the Proportional Custom Map

We suggest that the proportional and integral maps are not enabled until Map A for base WG Duty  has been profiled and is fairly close for good tight boost control.

We then suggest you create an overboost condition and then enable the proportional and integral maps in other modes to see the individual results.

The following sequence is great for producing an accurate proportional or integral map.

Ensure Map A is accurately calibrated so it delivers the correct boost pressure for a given target boost pressure then simply ADD minus -0.20bar to the X axis as shown below.

So now the column for 1.2bar becomes 1.0bar and WG Duty increases from 52% to 64%. When you select 1.0bar with RRBC you will get 1.2bar and you can see how the Proportional control deals with the overshoot, log the INTERIM and RESULT of Custom Map E to see the proportional component working.

If the boost reduces from 1.2bar to 1.1bar then you have to increase the proportional values for a 0.1bar boost error so the boost can be reduced further.

If the boost reduces from 1.2bar down to 0.9bar then you have to reduce the proportional values in Map E for a 0.1bar boost error.

We suggest you double or halve the values in Map E to increase or reduce the boost accordingly. The proportional addition should correct the boost instantly and there should be no over or undershoot if the proportional values are correct. 

In fact the output of Map E (Map A WG duty plus Map E Proportional WG Duty component) should be the actual the WG duty value shown in Map A before you rescaled the X axis.

Further on from this if you have not rescaled Map A X axis then the output of Map E shows the values you should enter into Map A at a given RPM if the boost error is zero(as Map E has corrected the WG Duty to produce the Target Boost pressure you have demanded).

This method can soon populate an accurate proportional map suitable for the size of your turbocharger.

Once your proportional map is calibrated then turn off Map E and enable Map F to calibrate Integral map in the same way.

Custom Map F - Wastegate Duty Integral Control

• X axis is the current Boost Error (Bar)
• Y axis is Engine Speed (RPM)
• Map values are Wastegate Duty Integral compensation factor.

In the example shown below the X axis is boost error (the difference between the Target Boost and Manifold Relative Pressure MRP). The Y axis is Engine Speed.

Custom Map F output value will be added the current WG Duty but as an integral, so the value will keep increasing over a period of time (several times a second).

The proportional value (output of Map E) will also be added if the proportional map has been enabled.

In this example at 3600rpm and -0.3bar boost error (so under the boost target) Map F will ADD a value of 0.06 to the current WG Duty (Map A plus Map E) therefore increasing the WG Duty. Assuming the current value for Map A to be 65 and Map E to be 26 then the WG duty will increase from 91% to 91.06% (65 + 26 + 0.06). 

But as the Output Definition is ‘Add map output to Integral, Add Integral to Channel’ then this 0.06 value will quickly increment on each calculation therefore causing the WG Duty to rise quickly over a time period for a continuous boost error.

If the boost pressure overshoots the Target Boost value then Map F Integral component will also REMOVE WG Duty.

If the rate of change (Increment or decrement) is too fast then halve the values and retest.  If the rate of change is too slow then double the values and retest. 

The Integral Min/Max has been set so it can only add or subtract a maximum value of 20, this prevents the Integral from drastically changing the WG duty over a time period like during spool and part throttle conditions.

To further improve the boost control logic the Integral control (Map F) has been configured with an Activation Definition.

As shown below the Integral control (Map F) is only allowed to work when the MRP is over 0.9bar and it will stop working below

0.88bar. So the Integral control can only adjust the WG Duty on full load. This will prevent the Integral from ramping up (or down) the WG Duty at part throttle conditions.

Calibrating the Integral Custom Map

The Integral will not correct the boost instantly like the proportional map does, the Integral takes times and you will see the boost reduce (or increase) over a time period (0.1 to 2 seconds). If the Integral takes too long to correct the boost pressure then double the values in Map F so the WG Duty reduces more quickly.

If the WG Duty redcues too quickly and the boost begins to oscillate then halve the values until the boost is more stable and then fine tune.

We cannot adjust the frequency of the integral addition but doubling or halving the values will have the same affect.

Below you can see an integral addition in action past 3500rpm when the activation pressure of 0.9bar was exceeded.

You can see the purple integral value (Map F Interim) constantly adjusting the WG Duty to maintain a zero Boost Error.

Our example screen shots and example ROM files have the proportional and integral values calibrated for stock turbo’s, larger turbo’s and stronger actuators will need smaller values in the maps (in theory).

Additional Boost Control calibration 

Other compensation factors can also be created, some examples below.

• Target boost pressure compensation for Coolant and Air temperature
• Per Gear Target Boost and WG Duty compensation
• Air Temp and Atmospheric pressure compensation

Note these compensations should be applied before any Proportional and Integral maps are implemented (so created as Map B, Map C or Map D)

Custom Maps Boost Limit

In addition a custom map can be used as a boost limit, this is useful if the boost is over 1.7bar and only 1 x 4bar map sensor is fitted in the plenum (Inlet Manifold) or a Speed Density kit is used where the charge air sensor is built into the MAP sensor but a 4bar sensor is not available.  If the pre throttle map sensor sensors are NOT changed then they cannot read over 1.73bar and therefore cannot be used for an overboost fuel cut protection. 

In this case set the Boost Limit (RaceROM) map to 1.9bar or greater so this limiter can never be reached (as standard MAP sensors can only read to 1.73bar) then we can configure a Custom Map as a boost Limit like shown below.

The X axis is MRP from the Plenum MAP sensor, the Y axis is RPM the output will multiply the Injector Size by 1 or 0. Note the X axis at 1.8bar will multiply the Injector size by 1 so will NOT change the Injector open time but at 1.81 will multiply the Injector size by zero which will cut the Injectors.

The activation for Custom Map G is set at 1.75 bar so the fuel cut cannot happen below this pressure but the resume is set to 1.1bar before the Injectors will restore, the timer activation is set at 1 second so quick spikes will not result in a fuel cut. 

How to set up Custom Maps Boost Control over 1.73bar

The Boost Error calculation is made using the pre throttle MAP sensors. If the pre throttle map sensors are still stock then they cannot calculate the boost error correctly over 1.73 bar (as 1.73 bar is the maximum they can read). 

This becomes a problem when the Plug and Play Speed Density MAP sensor containing a charge air temperature sensor is used and a 4bar MAP sensor cannot be fitted.

The answer is to use a custom map to calculate the boost error by comparing the RaceROM

Boost Controller (RRBC) Target Boost and Manifold Relative Pressure (MRP) like shown below.

9.5.1. Custom Map B - Calculating Boost Error

The difference between the Target RRBC value and the current Boost MRP is the boost error and this is stored as the Custom Map B Output. In the example screen shots shown below the RRBC target is 0.8bar but the MRP is actually 1.2bar so an overboost of 0.4bar (Custom Map B output)

• X axis is the RaceROM Boost Controller input (Bar)
• Y axis is Manifold Relative Pressure (Bar)
• Map values are Boost Error amount (Bar)

You can now use this Custom Map B boost error value as an input to the proportional or integral Wastegate duty maps like Map E or F on the previous Custom Maps Boost Control examples.

In this example we have set Custom Map C as a proportional map and in this situation Custom Map B Result of 0.4bar overboost would ADD -25% to the Wastegate Duty (so reduce the WG Duty by 25%).

You can see from the example log file screen shot that follows the RRBC target is 0.83bar (CYAN Line) but the current MRP is 1.13bar (GREEN Line) and the Custom Map B result shows the current boost error (YELLOW line).

If you want to keep the same Custom Maps Boost Control example as shown previously (How to set up Custom Maps Boost Control) then make the following changes to the maps A, E and F.

• Map A: change Desired Boost to RaceROM Boost Control as the X axis Input
• Map E: change the X axis Boost Error input to the Output of Custom Map B
• Map F: change the Y axis Boost Error input to the Output of Custom Map B

In addition add Custom Map B as a new map so it can calculate Boost Error using the plenum based 4bar map sensor.

Note the pre throttle map sensors cannot and should not be removed as a DTC will occur and the ECU will enter SAFE Mode , in addition the WG Duty will drop to 0%. If the Boost Sensor DTCs are disabled then the ECU will still be in safe mode so we advise that you leave them connected at all time.

Custom Map MFD Custom Data display

You can set up a custom maps to output certain values on the MFD digital coolant temp gauge. These logging parameters can be displayed during the map switching mode or can be configured to display a value permanently.

This feature has to be used with caution and understanding and should be used occasionally and not continuously as other modules on the vehicle will receive an incorrect coolant temp.

The example below shows how to set up for AFR Display in Map Switch Mode 4

The X and Y axis are the AFR Bank 1 logging parameter input.

The Output of Map O is a calculation only and changes nothing.

The output value is multiplied by 10 so 12.5 (AFR) would be 125.

The Coolant Temp Display setting for Mode 4 is configured to show the result of Map O ALWAYS. So when mode 4 is selected then the Digital Coolant Gauge will show AFR

You can also show Ethanol Fuel Content, Fuel Trim, Knock Correction, Ignition Timing but you need to consider the units that can be shown by the Coolant Gauge (no decimal points and Centigrade)