Evo Exhaust Manifold: Upgrade Guide

Upgrading your Mitsubishi Evo's exhaust manifold is a popular modification that can significantly improve its performance. The exhaust manifold is a crucial component that collects exhaust gases from the engine's cylinders and directs them into the exhaust system. An upgraded manifold can enhance exhaust flow, reduce backpressure, and ultimately increase horsepower and torque. Guys, if you're looking to boost your Evo's performance, this is definitely an area to consider!

Why Upgrade Your Evo's Exhaust Manifold?

There are several compelling reasons to upgrade your Evo's exhaust manifold. Let's dive into the benefits:

Enhanced Exhaust Flow

The stock exhaust manifold in many vehicles, including the Evo, is often designed with cost and manufacturing efficiency in mind. This can result in a more restrictive design that limits exhaust flow. An aftermarket exhaust manifold is typically engineered with larger diameter runners and smoother bends to facilitate a more efficient flow of exhaust gases. This improved flow reduces backpressure, allowing the engine to breathe easier and perform more effectively. When exhaust gases can exit the engine more freely, it translates to improved combustion and increased power output.

Increased Horsepower and Torque

By reducing backpressure and improving exhaust flow, an upgraded exhaust manifold can lead to noticeable gains in horsepower and torque. The engine doesn't have to work as hard to expel exhaust gases, which frees up energy that can be used to generate more power. The extent of these gains can vary depending on the specific manifold design, engine modifications, and tuning. However, it's not uncommon to see increases of 10-30 horsepower with a quality aftermarket manifold, especially when paired with other performance upgrades.

Improved Turbo Response

For turbocharged vehicles like the Mitsubishi Evo, an upgraded exhaust manifold can also enhance turbo response. A more efficient exhaust flow to the turbocharger allows it to spool up faster, reducing turbo lag and improving throttle response. This means you'll experience quicker acceleration and a more responsive driving experience. The manifold's design can significantly impact how quickly and efficiently the turbocharger can do its job, making it a critical component for maximizing turbo performance.

Better Sound

While performance is the primary focus, many enthusiasts also appreciate the enhanced sound that comes with an aftermarket exhaust manifold. The change in exhaust flow can result in a deeper, more aggressive exhaust note. The specific sound will vary depending on the manifold design and the rest of the exhaust system, but it's generally a welcome change for those seeking a sportier sound.

Types of Evo Exhaust Manifolds

When shopping for an Evo exhaust manifold, you'll encounter different designs and materials. Here's a rundown of the most common types:

Tubular Manifolds

Tubular exhaust manifolds are constructed from individual tubes that are welded together. This design allows for more precise control over runner length and diameter, which can be optimized for specific engine characteristics. Tubular manifolds are often lighter than cast manifolds and can offer superior performance, especially at higher RPMs. They are generally more expensive to produce, which is reflected in their price.

Cast Manifolds

Cast exhaust manifolds are made by pouring molten metal into a mold. This manufacturing process is more cost-effective than fabricating tubular manifolds, making cast manifolds a more affordable option. Cast manifolds are typically heavier and may not offer the same level of performance as tubular manifolds. However, they can be very durable and are often a good choice for street-driven vehicles.

Short Runner vs. Long Runner Manifolds

The length of the runners in an exhaust manifold can also affect performance. Short runner manifolds are designed to maximize flow at high RPMs, while long runner manifolds are optimized for low-end torque. Short runner manifolds are often preferred for racing applications where high-end power is the primary concern, while long runner manifolds can be beneficial for street cars where low-end torque is more important for daily driving.

Choosing the Right Exhaust Manifold for Your Evo

Selecting the right exhaust manifold for your Mitsubishi Evo depends on your specific goals and budget. Here are some factors to consider:

Performance Goals

What are you hoping to achieve with your Evo? Are you looking for maximum horsepower for track days, or are you primarily interested in improving low-end torque for street driving? Your performance goals will help you determine the best type of manifold for your needs. If you're aiming for all-out power, a tubular manifold with short runners may be the way to go. If you want a more balanced performance for street use, a cast manifold or a tubular manifold with longer runners might be a better choice.

Budget

Exhaust manifolds can range in price from a few hundred dollars to over a thousand dollars. Your budget will play a significant role in your decision. Tubular manifolds are generally more expensive than cast manifolds, so if you're on a tight budget, a cast manifold may be the more practical option. However, if you're willing to invest more, a high-quality tubular manifold can offer significant performance gains.

Supporting Modifications

Keep in mind that an exhaust manifold is just one component of the exhaust system. To maximize the benefits of an upgraded manifold, it's often necessary to upgrade other parts of the exhaust system as well, such as the downpipe and cat-back exhaust. Additionally, you may need to tune the engine to take full advantage of the increased exhaust flow. Consider the other modifications you plan to make to your Evo when choosing an exhaust manifold.

Material

Exhaust manifolds are typically made from stainless steel or cast iron. Stainless steel manifolds are more resistant to corrosion and can handle higher temperatures, making them a good choice for high-performance applications. Cast iron manifolds are more durable and can withstand more abuse, making them a better option for off-road or rally racing. The material of your exhaust manifold influences its durability and ability to withstand extreme conditions.

Installation Tips

Installing an exhaust manifold can be a challenging task, especially for those who are not experienced mechanics. Here are some tips to help you through the process:

Gather Your Tools

Make sure you have all the necessary tools before you start the installation. This may include sockets, wrenches, extensions, a torque wrench, and penetrating oil. Having the right tools on hand will make the job much easier and prevent frustration. Also, consider investing in a good set of exhaust manifold studs and nuts, as the stock hardware can often be corroded or damaged.

Disconnect the Battery

Before working on any part of the exhaust system, disconnect the negative terminal of the battery. This will prevent any accidental electrical shorts or shocks.

Use Penetrating Oil

Spray penetrating oil on the exhaust manifold bolts or studs several hours before you plan to remove them. This will help to loosen any corrosion and make the removal process much easier. You may need to apply penetrating oil multiple times over several days for heavily corroded hardware.

Follow the Torque Specifications

When installing the new exhaust manifold, be sure to follow the manufacturer's torque specifications for the bolts or studs. Overtightening can damage the manifold or cylinder head, while undertightening can lead to leaks. A torque wrench is essential for ensuring proper installation.

Use New Gaskets

Always use new gaskets when installing an exhaust manifold. Old gaskets can be compressed or damaged, which can lead to exhaust leaks. New gaskets will ensure a proper seal and prevent leaks.

Seek Professional Help If Needed

If you're not comfortable installing the exhaust manifold yourself, don't hesitate to seek professional help. A qualified mechanic can ensure that the job is done correctly and safely. Sometimes, it's better to leave it to the pros to avoid potential problems.

Conclusion

Upgrading your Mitsubishi Evo's exhaust manifold can be a worthwhile investment for those looking to improve performance. By increasing exhaust flow, reducing backpressure, and enhancing turbo response, an aftermarket manifold can lead to noticeable gains in horsepower and torque. When choosing a manifold, consider your performance goals, budget, and supporting modifications. And remember, proper installation is crucial for ensuring optimal performance and preventing leaks. Guys, with the right manifold and a little bit of elbow grease, you can unleash the full potential of your Evo!