Thank you for purchasing one of the most powerful engine managements systems, the Element Hydra EMS.   Every effort is made to offer tuned maps for your specific set of modification but some minor adjustments may be necessary to perfect the mapping.  Every car is unique and most likely there are areas that can be fined tuned and improved specifically for your car. 

It’s better to be safe than sorry so if you do not understand what you’re changing or the effects your changes make, please contact Element Tuning for technical support.   

Closed Loop Fuel

The Element Hydra EMS uses a closed loop fuel control system to maintain consistent performance and excellent fuel economy over a wide range of conditions.  The closed loop fuel control system utilizes the factory rear 02 sensor to maintain a 14.7:1 air fuel ratio for a specified range of RPM and vacuum.  This system utilizes a short and long term fuel trim just like your OEM computer to add or subtract fuel as required to maintain a 14.7:1 AFR.  To enable this function, click on the menu bar “Select/Settings/Closed Loop” for the Closed Loop menu.  

To turn on the system select "Enable Closed Loop" and "Enable Long Term Learning" (Do not enable with WB 02 Sensor).  Next you must set your "Lower RPM Limit" and your "Upper RPM Limit" as this tells the system when to turn on and when to turn off.  The default ranges are 1500 and 4350 RPM and don't forget to select the "enter" button to make the changes permanent.  Why we choose this range will be highlighted later in this guide.

The next step is to select your Module Sensor Source.  If you are using the OEM rear 02 sensor then you will select "14.7 Left U/Hego" for both the left and right module sensor sources.  WARNING:  If you are using a CEL eliminator or other mechanical CEL fixes for the rear 02 sensor these must be removed so an accurate signal is sent to the computer.  If you are using the optional Element Hydra WB 02 sensor in place of the factory 02 sensor then you will select "14.7 Wide band Hego" for both the left and right module sensor sources.

Closed Loop Limit

The "Closed Loop Limit" specifies the maximum vacuum you would like the system to be active up to for the 14.7:1 AFR.  This can be specified over various RPM ranges.  For instance you may want to run a 14.7:1 AFR up to 4500 rpm but you would prefer to run open loop fuel control thereafter so you would set your maximum vacuum to 3 mmhg up to 4500 rpm and to 760 mmhg after 4500 rpm. 

You also have the choice of running a 14.7:1 AFR for the entire RPM range up to a specified vacuum limit.    For instance, set your maximum vacuum to 3 mmhg up to 4500 rpm and after 4500 rpm set your maximum vacuum to 385 mmhg.  This means as long as the vacuum is 385 mmhg or greater the car will run at 14.7:1 AFR for the entire RPM range but when the vacuum is less than 385 mmhg it will run in open loop fuel mode.  Don't forget that you must change your "Lower RPM Limit" and your "Upper RPM Limit" in the "Settings" menu under "Closed Loop."

AutoTune Fuel

You can enable the ecu to perform a closed-loop operation of the entire fuel map with the AutoTune feature.  In this mode the ecu will automatically adjust fueling to achieve the desired air fuel ratios set in each load site and permanently correct your fuel mapping.  For instance if your goal is to run 14.7:1 under vacuum, 11.3:1 up to 12 psi, and 10.9:1 at 18 psi, the ecu will automatically adjust the fueling to meet this criteria.  Since the AutoTune feature requires the optional Element Hydra specific wide band 02 sensor you must install this into your exhaust system post turbocharger.  To ease installation you can uninstall your factory rear 02 sensor and utilize that location for the WB.

To enable this function, click on the menu bar “Select/Settings/Closed Loop” for the Closed Loop menu.   To turn on the system select "Enable Closed Loop" and "Enable AutoTune (with DRQ)."  Next set your "Lower RPM Limit" and your "Upper RPM Limit" as this tells the system when to turn on and when to turn off.  I recommend starting at 2000 RPM and ending at your maximum RPM and don't forget to select the "enter" button to make the changes permanent.  I generally don't recommend using the AutoTune feature for idle control as it may cause the idle to hunt which is why we recommend setting the "Lower RPM Limit" to 2000 RPM. 

The next step is to select your Module Sensor Source.  Select "Wide Band Target Table" for both the left and right module sensor sources.  This tells the ecu to use the "AFR Target" table to determine what air fuel ratio to run.

Air Fuel Target

The "AFR Target" table defines the air fuel ratio while using the "Wide Band Target Table" feature.  Simply input the desired AFR in the 32x32 map of vacuum/pressure over RPM and the closed loop system will compare this target to the injector pulse width of the main fuel map and make changes as required.  To make adjustments, click on the menu bar “Select/AFR Target” for the AFR Target menu.

AutoTune Rate

The AutoTune rate determines how aggressively the AutoTune makes changes to the fuel map.  If the AutoTune rate is low then it will take longer to reach the target AFR but it will be very smooth.  If the rate is set high then changes will be made faster but the AFR may not be as smooth.  Obviously somewhere is the middle is ideal.  To make these adjustments, click on the menu bar “Select/Control 3/Autotune rate” for the AutoTune Rate menu.  

The AutoTune rate is adjustable over 16 rpm ranges.  The default is 16 which will results in very smooth changes but may take 3-4 pulls to correct the "Fuel" map to reach the values in the "Target AFR" map.  For coarse tuning or when the map is pretty far off target I like to use 25 as this only takes 2-3 pulls to reach your target AFR.  If you find you're on target within a certain RPM range then you should keep the AutoTune rate minimal but if there is an RPM area that is slow to change then increase the rate.  I don't recommend going higher than 30 for road tuning as it will result in some hesitation as corrects the fuel map.

Upload

Before you can see any changes to the AutoTune programming you must first select “Upload from ecu” so you can view the mapping in your unit.

Select “Upload” and once the upload process is complete the menu will disappear and you can select “Maps” to view the file.  Here is what you will see: 

It's really difficult to hit every point of the map with AutoTune so it's good tuning practice to go into your fuel map and smooth everything in.  This can be done visually while looking at the 3-D graph.  Once you smooth everything out you must save and download to make your changes permanent.

Save and Download 

To make your changes permanent you must save these changes to your laptop and download them to your Element Hydra.  Select “Maps” on the menu bar and then select “Save.”  Logically name the file and save it to your hard drive. 

Close the red tuning screen to view the “Download” screen.  Select “Download” and then “Download” again using the appropriate com port.  Once the download is complete you can select exit. 

The last and most critical step is that you reset your Element Hydra ECM by turning the ignition to the full off position to reset the ecu.  This usually takes 10-15 seconds.  Your changes are now permanent. 

Don't forget to double check your work to make sure you're AFRs match your target.  If they do not then repeat the process until everything is to your liking. 

Our next discuss will be more fuel tuning. Click to view Element Tuning Guide 3

Stay tuned!

Phil Grabow

www.elementtuning.com