Tuning FAQ

Note: This section has had very little in the way of contributions and is not, in its current form, anything close to a comprehensive tuning guide. The RomRaider forums contain the most up-to-date and useful tuning information.

QHow do I tune my car?

Tuning is an iterative process.

1. Read the current ROM image from your car. RomRaider cannot actually help with this - this step requires EcuFlash. Also note that most cars must be put into ‘test mode’ for reading or writing.
2. Learn about the car’s behavior with the current ROM image, using a logger or other data-collection tool to gather log information from your car as you drive.
   1. RomRaider’s logger will record arbitrary parameters in real time.
   2. RomRaider’s MAF scaling tab will plot your MAF sensor’s results and help you tune the scaling
   3. RomRaider’s injector scaling tab will plot your fuel injectors’ behavior and you adjust scaling at latency
   4. The “SawMill” utility (by natewaddoups) will display knock in different load/rpm cells
   5. The “Learning View” utility (by merchgod) shows fuel trims and fine learning knock correction (and actually works just as well with the parked).
3. Look for problems such as knock, boost oscillations, boost that is lower or higher than desired, etc.
4. Consider opportunities to improve, such as timing that can be advanced, boost that can be increased, etc. This depends not only on your recent logs but also on your experiences with past logs.
5. Use RomRaider to edit your ROM image, making changes to address problems or opportunities that you’ve found.
6. Write your modified ROM image to your car. (Again, this step requires EcuFlash and most cars must be put into test mode.)
7. Go back to the second step

QI know relatively little about tuning and logging. Where should I start?

If you are just starting out, you will want to:

• Read the RomRaider FAQ.
• Learn to use EcuFlash to read your ROM, so you can view it in RomRaider.
• Learn to use RomRaider to log data from your car.
• Learn everything you can about tuning and logging. RomRaider’s tuning discussion forum is an excellent place to start.
• Read the following posts about ECU logic:
  • Subaru’s knock control strategy explained
  • Closed Loop to Open Loop fueling transition explained
  • Turbo dynamics and boost control explained
• Learn to use RomRaider to edit your ROM
• Learn to use EcuFlash to write your modified ROM to your car’s ECU.