What is Stage 2 Tuning?

Stage 2 tuning advances vehicle performance beyond the basic software adjustments of Stage 1 (Tuning). While Stage 1 focuses on optimising the engine’s existing software to enhance power and efficiency using the original hardware, Stage 2 involves upgrading that hardware itself.

This advanced stage is suited for those looking to significantly improve their vehicle’s capabilities through comprehensive modifications. It includes substantial changes to the air intake and exhaust systems, upgrades to the fuel system, and more. These modifications increase power, enhance efficiency, and improve the overall responsiveness of your vehicle, making the upgrades noticeable not just on a dyno but also during every day driving.

Potential Power Gains

Stage 2 tuning can offer significant power increases, typically ranging anywhere from 20-40% depending on your vehicle and the specific upgrades installed.

For instance, upgrading to a high-flow exhaust system can enhance horsepower and torque by improving exhaust flow. Installing a larger turbocharger boosts engine performance, while a performance air intake ensures an optimal air-fuel mixture. Advanced ECU remapping fine-tunes these enhancements to maximise power output. Combined, these modifications can transform your car significantly.

Popular Stage 2 Upgrades

Stage 2 tuning is where you really begin to see major performance gains, significantly changing how the car feels and responds. In this section, we introduce the more advanced modifications that build on the groundwork laid out in stage one.

Catback Exhaust System Diagram

Catback Exhaust System from APR

Exhaust System Enhancements

Having started with cat-back exhaust upgrades in Stage 1 to enhance the vehicle’s sound and efficiency, Stage 2 progresses to more intensive changes. This stage introduces turbo-back for turbocharged engines or header-back exhaust systems for naturally aspirated engines.

By replacing the entire exhaust system from the turbo or headers to the back, including the downpipe, midpipe, and sometimes the catalytic converter, these modifications greatly reduce exhaust backpressure. This allows the engine to breathe more freely, leading to higher power gains from other Stage 2 upgrades.

If the catalytic converter wasn’t upgraded in Stage 1, introducing a high-flow catalytic converter during Stage 2 can further enhance exhaust flow. This supports the increased air and fuel from more advanced tuning stages, boosting power and ensuring the engine runs more efficiently, even at higher outputs.

Advanced Air Intake System Enhancements

Building on the initial air intake upgrades from Stage 1, Stage 2 takes the air induction system even further. Often, the entire intake assembly is upgraded to a full-performance intake kit. These kits are designed to significantly increase the volume and flow rate of air entering the engine. They feature larger, smoother tubes and less restrictive bends, which help optimise the delivery of airflow to the engine.

If Stage 1 included a basic cold air intake system, Stage 2 upgrades might further optimise it to draw the coolest air possible. This could involve rerouting the intake duct to a location with better access to cooler, ambient air, like a lower front grille position, or adding extra shielding to protect the intake air from the heat of the engine bay.

Want to learn more about air intakes? Check out this guide.

Enhanced Fuel System Modifications

The more aggressive air intake upgrades in Stage 2 bring in a lot more air, both in terms of volume and density. To match this, the fuel system also needs to be stepped up. Larger capacity injectors are essential to provide enough fuel to keep up with the increased airflow. This is vital for keeping the engine running smoothly and efficiently.

Additionally, to make sure these high-capacity injectors work as intended, it’s often necessary to upgrade the fuel pump as well. A higher flow rate fuel pump ensures that the fuel pressure and volume stay consistent, even under high-performance demands. This helps avoid any delay in fuel delivery, which is crucial for maintaining engine performance and safety.

Turbocharger & Intercooler Upgrades

Replacing the stock turbocharger with a larger or more efficient model can significantly increase the amount of air being forced into the engine.
This increase is crucial for achieving the desired increase in power and torque when combined with the upgraded fuel and air intake systems.

For vehicles that can accommodate it, adding a second turbo (twin-turbo) or transitioning to a bi-turbo setup can dramatically improve performance, offering quicker turbo spool-up and reduced turbo lag, thereby providing a more consistent power delivery across a broader RPM range.

With the increase in turbocharger efficiency, upgrading the intercooler becomes even more important to handle the higher volumes of heated air. A larger or additional intercooler can provide much-needed cooling capacity to reduce the temperature of the air being forced into the engine by the upgraded turbocharger. This cooling is vital to maintain the air density required for optimal combustion.

Advanced ECU Remapping

After investing in some serious upgrades, a more intensive ECU remap is required to fully optimise the engine’s performance. This remap involves recalibrating the engine control settings to account for significant changes such as the increased airflow from a more efficient intake system, the reduced backpressure from an improved exhaust system, and the higher fuel delivery demands from upgraded fuel injectors and pumps.

The remapping process adjusts critical parameters like fuel injection timing, ignition timing, and air/fuel ratios. It also refines the boost control for turbocharged engines, ensuring that the turbocharger’s increased capacity is effectively utilised without harming the engine. This careful calibration helps manage the enhanced outputs to prevent engine knock and ensure smooth power delivery across different driving conditions.

Suspension and Brakes

With increased power comes the need for enhanced handling and braking. That’s why upgrading both your brakes and suspension is crucial for a Stage 2 tune. In terms of suspension, numerous options are available. Installing coilovers can be a smart choice, as they allow you to customise the ride height and stiffness to your driving needs. This adjustability improves handling, reduces body roll during cornering, and gives you the opportunity to lower your car.

With more power under the hood, many drivers upgrade to a big brake kit. This usually includes larger rotors, high-performance brake pads, and multi-piston callipers. These upgrades give you the necessary stopping power to handle the increased performance, ensuring safer and more reliable braking, especially under intense driving conditions.

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