Replacing a Turbocharger with a Supercharger: Power Increase and Considerations

Introduction

Have you ever considered whether a supercharger can replace a turbocharger in a car? While it is possible, it comes with a series of challenges and benefits that make it a significant undertaking. This article will explore the steps involved, the power increase, and the trade-offs between the two types of supercharging.

Installation and Adjustments

Replacing a turbocharger with a supercharger is not as straightforward as it might seem. The process involves changing several parts to accommodate the supercharger, including a different exhaust manifold, exhaust, intake manifold, and even the intake air filter. Additionally, the Electronic Control Unit (ECU) may need to be re-tuned and injectors possibly replaced. All of these modifications are necessary to ensure proper performance and efficiency.

Can You Replace a Turbocharger with a Supercharger?

Technically, you can replace a turbocharger with a supercharger, but it is not a simple DIY project. The modifications required make it more practical for professional automotive modification shops with experience in such builds. Here are some critical steps:

Install a different exhaust manifold and exhaust Replace the intake manifold and intake air filter Retune the ECU for optimal performance Consider upgrading fuel injectors if needed

The Power Increase

While you can replace a turbocharger with a supercharger, the power increase is not always significant. The amount of power gained depends on several factors, including the engine's condition, the turbocharger's efficiency, the supercharger's type, and the desired boost levels.

Generally, a supercharger can provide more linear power delivery across the RPM range compared to a turbocharger. However, achieving a substantial power increase requires a large supercharger and typically results in more power than the original turbo setup. For most street cars, you might find that the power increase is similar or slightly less, but the torque curve shifts toward a broader range.

Turbochargers vs. Superchargers

Turbochargers and superchargers both force more air into the engine, increasing its power output. The main differences lie in how they generate pressure. Turbochargers use exhaust gases to spin an impeller, while superchargers are driven by a belt from the engine's crankshaft.

Turbochargers are known for their efficiency, as the energy in the exhaust is harnessed. However, they can suffer from turbo lag, which is the delay in reaching peak turbine speed and providing boost. Superchargers, on the other hand, have a quicker response time but consume more power from the engine, which can reduce overall efficiency and fuel economy.

Power Gains

Power gains from either a turbocharger or a supercharger can be significant, especially if the engine is well-built and the modifications are done correctly. However, the gains are not always linear, and the trade-offs between the two types of supercharging can vary.

In some cases, you can gain 50 or more horsepower reliably with either system. For street use, a turbocharger is often preferred due to its more acceptable boost delivery and higher reliability. Professional race cars use both turbo and superchargers, but these setups often include extensive tuning and modifications.

Real-World Example

Consider an engine similar to a 572 CID Chevrolet. Without a supercharger, it produced about 700 horsepower. With a supercharger, it can reliably produce 1850 horsepower and run up to 15 seconds at full throttle between rebuilds, totaling over 300 seconds. This level of performance is unmatched by many conventional engines, even those with much larger displacement.

For comparison, Top Fuel and Funny Car engines achieve around 8000 to 10000 horsepower but only last for a few seconds before needing rebuilding. These engines are pushed to their limits, showcasing the extreme power that can be achieved through supercharging.

Conclusion

Replacing a turbocharger with a supercharger is possible, but it requires significant modifications and can be challenging for the average mechanic. The power increase depends on the specific setup and desired outcome. While the supercharger can provide a broader torque curve, the gain is not always substantial and comes with additional costs and work.

Regardless of whether you choose a turbocharger or a supercharger, the important thing is to understand the benefits and limitations of each. Professional consultation and proper engineering are crucial to achieve the best results.