Upgrading to 70mm Individual Throttle Bodies on a Subaru Wrx: Power Gains and Costs

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The Subaru WRX is a beloved vehicle among car enthusiasts, known for its performance and handling capabilities. One popular modification among WRX owners is upgrading to 70mm individual throttle bodies (ITBs). This article explores the power gains and costs associated with this upgrade.

Understanding Individual Throttle Bodies

Individual throttle bodies allow each cylinder to have its own throttle mechanism. This design can improve airflow and responsiveness, leading to increased power output. The Subaru WRX, especially in its turbocharged variants, can significantly benefit from this upgrade.

Power Gains from 70mm ITBs

Upgrading to 70mm ITBs can provide substantial power gains for the Subaru WRX. Here are some key points to consider:

  • Increased Airflow: The larger diameter of the throttle bodies allows for more air to enter the engine, which can lead to better combustion and more power.
  • Improved Throttle Response: ITBs provide a more direct connection between the driver’s input and the engine’s response, resulting in quicker acceleration.
  • Enhanced Tuning Potential: With individual throttle bodies, tuning options expand, allowing for a more customized engine performance.

Cost Considerations

While the performance benefits of upgrading to 70mm ITBs are appealing, it’s essential to consider the costs involved. Here’s a breakdown of potential expenses:

  • Throttle Body Kit: The cost of a 70mm ITB kit can range from $1,000 to $3,000 depending on the brand and included components.
  • Tuning: Proper tuning is crucial after installation, which can add another $500 to $1,500 to the overall cost.
  • Installation: Professional installation may be required, costing between $300 and $800, depending on labor rates.

Installation Process

Installing 70mm ITBs on a Subaru WRX is a complex process that requires mechanical knowledge. Here’s an overview of the steps involved:

  • Preparation: Gather all necessary tools and components before starting the installation.
  • Remove Existing Throttle Bodies: Disconnect the intake and remove the factory throttle bodies from the manifold.
  • Install ITBs: Carefully install the new 70mm throttle bodies, ensuring proper alignment and sealing.
  • Reconnect Intake: Reattach the intake system, ensuring all connections are secure.
  • Tuning: After installation, the vehicle must be tuned to optimize performance with the new throttle bodies.

Potential Challenges

While the upgrade can yield impressive results, there are potential challenges to consider:

  • Engine Management: The factory engine management system may not support the new ITBs, necessitating an aftermarket ECU.
  • Intake Design: The design of the intake manifold may need modification to fit the new throttle bodies properly.
  • Driveability: Some drivers may experience changes in driveability, especially at low RPMs.

Conclusion

Upgrading to 70mm individual throttle bodies on a Subaru WRX can provide significant power gains and improve throttle response. However, it is essential to consider the associated costs and potential challenges of this modification. For those willing to invest in their vehicle, the rewards can be well worth it.