How to Tune an RX8

The Mazda RX-8 is a highly advanced vehicle that can cost a lot of money to maintain. Performing tune-ups and oil changes yourself can be very cost-effective and it will also teach you the ins and outs of the vehicle in case anything needs to be repaired. Tuning your engine takes time and patience, but the benefits far outweigh the negatives.

Things You'll Need

  • Worldwide diagnostic system device
  • Timing light
  • Exhaust gas analyzer

Engine TuneUp Preparation

  • Place your gear selector in the Park (P) or Neutral (N) position.

  • Turn off all electrical accessories, such as the air conditioner and radio.

  • Press the gas to increase speed to 2,500 to 3,500 rpm and wait until the cooling fans turn on. The vehicle will be in park or neutral, so it will not move during this step.

  • Release the accelerator when the cooling fans turn on. Wait until the cooling fans stop running before continuing work.

  • Connect a diagnostic device (WDS) to the DLC-2. The DLC-2 is located underneath the steering column and to the left of the steering wheel near the pedals. It will look like a rectangular bay that has nothing plugged into it.

  • Check that the idling speed of the vehicle is at 760 to 860 rpm for an automatic transmission or 750 to 850 rpm for a manual transmission. The code on the diagnostic device that designates rpm should read "RPM PID."

Inspect the Ignition Timing

  • Connect the timing light to the front rotor housing. The front rotor housing is on the front of the engine facing toward the front bumper.

  • Turn on the "test mode" on the timing light. In order to enter the timing light into test mode, you must use the "Test Simulation" function.

  • Confirm the positions of the "Eccentric Shaft Plates". On the front of the motor, you should see that the front cover of the rotor housing has a white mark on it. The engine itself also has a white mark. The white marks should be lined up correctly.

  • Confirm the ignition is -5 degrees. Using the diagnostic device, you should find this under the "SPARK-L" section.

  • Turn the test mode off.

Inspect the Idling Speed

  • Turn on the "test mode" on the timing light. In order to enter the timing light into test mode, you must use the "Test Simulation" function.

  • Verify engine speed, using the RPM DATA function on the diagnostic device. Because you should have all loads turned off --- headlights, air conditioner, heat, defrosters --- turned off, the idling speed should be 760 to 860 rpm for an automatic transmission or 750 to 850 for a manual transmission.

  • Turn the "Test Mode" off.

Check That the Idle Mixture Is Within Regulation

  • Complete steps 1, 2, and 3.

  • Place the exhaust gas analyzer stick into the tailpipe.

  • Verify that the emissions level is up to EPA standards. The NOx level should be 0.07. tTe NMOG level should be 0.055, the CO level should be 2.1. The PM level should be 0.01, and the HCHO level should be 0.011.