EFI Install

Just finished up a fully complete Motorsport ECU/Dash/Expansion install with @ratchethead racing for a flawlessly prepped E36 M3.  This car has a US spec BMW S52 engine and wiring harness.

This car has nearly all of the features enabled that the Emtron system can offer.  It uses all of the factory inputs and outputs flawlessly, as well as the following additional inputs :

Twin wideband lambda sensors

Manifold pressure sensor

Fuel pressure sensor

Oil pressure sensor

Oil temperature sensor

Calibration switch (steering wheel mounted)

Fuel used reset switch (steering wheel mounted)

Ground speed limit switch (steering wheel mounted)

Traction control (dash mounted multi-position)

The extra inputs are ran to the ECU (rather than display and/or loggers) so they can be used for true speed density VE fuel modeling, load calculation, and calibration compensations.  The high input/output count of the Emtron KV8 ECU allows this.  Proper engine trips (failsafes, sensor fault detection with substitute values, etc) can also be configured.  All these auxiliary components now go to one place as well, instead of being wired to various components for data collection.

All factory plugs and sensors are used (besides narrow band lambda sensors) including the factory engine harness (Plug and play – first of its kind).  Harness additions are documented and clearly labeled for ease of use using Deutsche expansion plugs.   This system can easily be configured to add on electric throttle capability as well.  

The setup of additional sensor inputs along with a properly characterized fuel system allow the Emtron efficiency strategy to thrive.  A separate post is needed to elaborate on this system’s performance, consistency, flawless drivability, efficiency, and overall control.  Since this vehicle will be used for endurance racing, the Emtron true fuel consumption calculation will be a value tool.  

For data acquisition and display (besides the included onboard ECU logging), we enabled an advanced logging set to be received by an @AIM MXL Pista dashboard.  AIM supports a specialized Pavlotech/Emtron configuration that can receive over 60 customized ECU parameters. These can all be recorded, configured for display, and/or alarms.  Almost every sensor input and calculation from the ECU is available over the network which is just two wires going to the dashboard!  This further allowed us to create new alarm functions for fuel consumption that trip when 90% of the fuel capacity is used up, instead of watching a gauge that is inaccurate.  

On top of all of this, this car is now capable of motorsport traction control that is incomparable to any other system in this market.  The strategy uses the ECU’s internal G sensors to develop slip thresholds based on longitudinal and lateral load.  The configuration is highly comprehensive with full closed loop control.  There is also a dash mounted multi-position switch to control the traction systems sensitivity!

If you are ready for real, serious, and professional solutions for your competition vehicle, please contact @pavlotech soon to discuss your options!  


Map Switching


A frequent (and sometimes controversial) question comes up a lot since vehicle electrical systems continue to evolve .  What is map switching?  The short answer is the ability to change the ECU look up table reference points.  While that sounds complicated, this can be a very simple concept.  

A good example would be a car with electronic throttle control that has a “sport” switch that changes the sensitivity.  The ECU would have multiple look up tables for throttle targets which is then dependent on a switch (or something else) to actively change it.  Attached are examples of two electronic throttle target tables.  The axis for the look up tables are configured to follow RPM and pedal position.  You can see the relationship between the pedal and target throttle position is not linear in either map.  This is normal contrary to popular belief (especially if the application uses a very large throttle body or individual throttles), but regardless of that, each map has a different pedal to throttle curve which is what changes the throttle sensitivity.


With modern electronics, map switching can be configured to much more than simply change the throttle sensitivity of the engine.  While the examples I am showing you are utilizing the @emtron #emtune calibration software, some (if not many) of these functions can be configured in a modern factory ECU as well.  

Attached is an example of the CAL (calibration) slot control page in Emtune.  You can see there are 4 CAL slots on the top which correspond to multiple tables for various functions of the ECU.  You can change every important look up table of the calibration based on the position of the CAL slots at the top.  To add flexibility, Emtune lets you define however you want to control the slot change as well.  You can have a multi position switch telling the ECU what slot you want to be in, change slots based on an analog voltage, change slots based on speed, or change slots based on temperature.  The configuration is totally open so you can do almost anything you want.  They even give you a 3D table to configure this based on multiple axis.  


Emtune also has some advanced features that allow you to “blend” tables automatically in addition to the above mentioned CAL slot control.  This is called their Z-Axis function.  In one of the attachments the configuration is shown where, based on vehicle speed, a boost target table (in KPA) is automatically switched (and blended automatically when in between).  Z-Axis is available for almost any important map within the Emtron ECU systems.  


In addition to some of the reasons why map switching can be useful above, here is a quick list of common examples:

Drive by wire target

Fuel mixture table

Octane switch

Boost target switch

Launch mode enable

Ground speed limit enable

Logging enable

Valet mode

Torque limit switch

Map switching can be very useful in race series that base car classification on power to weight.  The car can be set up to run in a number of classes by changing parts, installing a restrictor plate (to limit engine power), or switching the calibration.  

Hopefully after reading all of this you can see how being able to switch calibrations could be useful in this instance.  Especially if the car has electronic throttle!  

While this subject can be highly controversial (due to making it easy to cheat), if used LEGITIMATELY it can yield impressive results further justifying investing in the proper electronics solutions.  

Attached is a dyno plot using running two different calibrations so the same car can be used in two separate racing classes that are based on power to weight.  The max power and detuned run were NOT back to back here (you can see the detune was several runs after the max run), so there was some heat soak.  Even still, the detuned plot shows essentially maximum torque available until the peak HP is “clamped” at roughly 6000rpm.  


This was done properly with a number of calibration changes that included throttle target tables, proper fueling changes, ignition correction, cam position, Emtune torque limiting tables, and more. Rather than simply installing a restrictor plate which usually relies on an automatic function to compensate for reduced airflow, each calibration slot is customized, consistent, and therefore reliable.  

Interested in learning more?  Feel free to contact @pavlotech to discuss the options!