AEM’s Plug and Play ECU for the Chevy LS1, a Swappers Delight!

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The AEM LS1 plug and play EMS comes with the circuit board that replaces the stock part, a special ECU case lid, a serial port tuning dongle and the tuning software.

Since the LS1 has so many tuning options, being able to have full control of engine management is a huge advantage when putting together one of the new generation hybrids.  We found a great remarkably simple solution for tuning with AEM’s plug and play EMS for the LS1.  Our test subject is a 1993 FD RX-7 with a bone stock 2001 LS1 swapped into it.  To install the AEM EMS, we simply unplugged the stock ECU, swapped the top of the factory ECU onto the AEM board and plugged it back into the stock harness.  This is an exceedingly nice and clean installation—no cutting or hacking of wire harnesses.  This also means that if the car needs to be repaired later, you can simply get inexpensive and easy to find stock sensors!  The factory ECU can also easily be returned to stock in a matter of minutes if so desired.

In order to use the AEM EMS datalogging function to speed tuning, we used AEM’s remarkably easy to use in line UEGO controller to log the air fuel ratio.  AEM’s in line UEGO controller can be used with any datalogger or ECU with a data logging function.

To aid in our tuning of the AEM EMS we used its internal data logging function which was made easy by the AEM Inline Wideband UEGO controller.  We replaced the standard GM O2 sensor with the supplied Bosch LMU-4 wide band UEGO O2 sensor then wired the sensor to AEM’s inline UEGO controller to the O2 sensor #1 input on the EMS.  The inline UEGO controller makes datalogging of the air fuel ratio through the EMS very easy.  The controller is compact and easy to install providing heater control and signal conditioning in one easy to use package.  We will be writing more about this innovative product in a future article.

We used the AEM supplied Bosh LMU-4 wide band O2 sensor to measure our air fuel ratios.

The AEM plug and play EMS easily starts the car without having to tune it first.  It comes calibrated for use with the stock sensors with the exception of the LS1’s mass air flow or MAF sensor.  Instead, the AEM EMS uses the stock manifold absolute pressure or MAP sensor to help determine load.  This is cool because it enables us to remove the potentially restrictive MAF from the intake.  We didn’t physically remove the MAF for this test but will do it at a later date.

The AEM EMS fits inside the stock GM ECU housing so the stock circuit board must be replaced with the AEM part.

These small brackets are installed on the factory case-heat sink.  The AEM circuit board attaches to these.

The AEM suppled lid and circuit board then attach to the case bottom and heat sink.

After installing the hard parts we powered our RX-7 up and reloaded the supplied V1 2.1 firmware and the 1220 startup calibration.  We then calibrated our throttle position sensor with the TPS set up wizard in the firmware and selected the correct MAP sensor using the MAP set up wizard.  We then selected the option of TPS based fuel map and put a 1:1 MAP sensor fuel correction in.  We are going to run the car in Alpha N mode with a MAP correction.  Alpha N in English is calculating the fuel to be injected based on throttle position and RPM.  The MAP correction means that this calculation is modified by using MAP input to estimate load better.  This typically gives good driveabilty and throttle response. Next we had to manually set the O2 sensor calibration curve since there is not a set up wizard for the AEM inline UEGO controller.  However this is very easy and the values are supplied with the instructions for the controller.  Although this might sound complicated, AEM’s software makes the initial set up very simple.

The final product buttoned up and ready to drop in our RX-7