Engine Tuning for Autocross Racing: A Comprehensive Guide

Engine tuning for autocross racing is a complex and multifaceted process that involves the optimization of various engine parameters to improve the performance of the vehicle during these high-intensity events. This process typically involves the use of advanced data logging systems to measure and analyze a wide range of engine and vehicle parameters, including engine RPM, longitudinal and lateral acceleration, throttle position, brake position, and steering angle.

Sensor Setup and Data Acquisition

One of the critical aspects of engine tuning for autocross racing is the use of wideband O2 sensors, which are essential for EFI programming and can help deliver accurate horsepower calculations. These sensors provide real-time data on the air-fuel ratio, which is a crucial factor in engine performance and efficiency.

In addition to the wideband O2 sensors, a comprehensive data logging setup for autocross racing should also include the following sensors:

  1. Exhaust temperature sensors: These sensors provide valuable data on the engine’s thermal management, which can be used to optimize ignition timing, fuel delivery, and other engine parameters.
  2. Air inlet temperature sensors: These sensors measure the temperature of the air entering the engine, which can be used to adjust the fuel-air mixture and optimize engine performance.
  3. Voltage sensors: These sensors monitor the electrical system of the vehicle, ensuring that the engine is receiving the appropriate voltage for optimal performance.
  4. Oil pressure sensors: These sensors provide data on the engine’s lubrication system, which is essential for maintaining engine health and preventing damage.
  5. Water temperature sensors: These sensors monitor the engine’s coolant temperature, which can be used to optimize the engine’s thermal management and prevent overheating.

The minimum data logging setup for autocross racing should include the following parameters:

  • Vehicle speed
  • Throttle position
  • Brake position
  • Engine RPM
  • Longitudinal and lateral acceleration
  • Steering angle
  • Minimum sample rate of 100Hz

Additionally, useful math channels for analysis can include shock velocity, roll angle, gear/clutch slip, delivered horsepower, and suspension position sensors for suspension development.

Data Analysis and Optimization

engine tuning for autocross racing

When it comes to data analysis, it’s important to focus on the delta, or the difference in performance between runs, rather than just peak output numbers. This involves analyzing data such as differential throttle and steering angle to identify areas for improvement in driver inputs and car development.

By analyzing the data collected from the various sensors, drivers and tuners can make adjustments to the engine and vehicle parameters to improve performance. This may include adjustments to the following:

  1. Ignition timing: Adjusting the ignition timing can help optimize the engine’s power output and efficiency.
  2. Fuel delivery: Adjusting the fuel delivery system can help ensure the optimal air-fuel ratio for different driving conditions.
  3. Boost control: For turbocharged engines, adjusting the boost control can help optimize power output and prevent engine damage.
  4. Suspension tuning: Adjusting the suspension settings can help improve the vehicle’s handling and stability during autocross events.
  5. Aerodynamics: Adjustments to the vehicle’s aerodynamics, such as wing settings and splitter configurations, can help improve downforce and reduce drag.

By continuously analyzing the data and making adjustments to the engine and vehicle parameters, drivers and tuners can optimize the performance of the vehicle and gain a competitive edge in autocross racing.

Conclusion

Engine tuning for autocross racing is a complex and multifaceted process that requires a deep understanding of engine and vehicle dynamics, as well as the use of advanced data logging and analysis tools. By setting up a comprehensive data logging system, analyzing the data, and making targeted adjustments to the engine and vehicle parameters, drivers and tuners can improve the performance of their vehicles and achieve success in autocross racing.

References:

  1. Autocross to Win (DGs Autocross Secrets) – Data Logging
  2. it’s all about the delta – Obsidian Motorsport Group
  3. Lambda and engine tuning in data – Porsche Discussion Forums