Unleashing Potential: The Evo X Intake Manifold Explained
Owners of the Mitsubishi Lancer Evolution X never stop improving horsepower. While turbochargers and exhaust systems often steal the spotlight, one critical component hidden under the engine cover is a powerhouse in its own right: the Evo X intake manifold. Understanding its function, potential, and how to improve it is key to unlocking your vehicle’s true performance.
What is the Evo X Intake Manifold?
This part is an engine element mounted directly atop the cylinder head. Its primary job is to distribute the air-fuel mixture (or just air in direct injection engines like the Evo X’s 4B11T) as evenly as possible to each cylinder. The factory Evo X intake manifold is a precision-crafted part made from cast aluminum, designed to balance reliability, emissions, and performance straight from the factory. It features integrated channels and a plenum—a chamber where air can collect and stabilize before being sent to the runners that feed each cylinder.
What is it For? The Science of Air Delivery
Consider the intake manifold to be the motor’s breathing apparatus. Following the intercooler, air proceeds directly into the plenum chamber. This chamber is crucial for mitigating pulsations from the turbocharger, creating a reservoir of pressurized, cool air. When the intake valves open, the manifold’s runners guide this air into the combustion chambers. The design of this system—the plenum volume, runner length, and internal surface finish—directly impacts volumetric efficiency, which is the engine’s ability to fill its cylinders with air. Better volumetric efficiency means more oxygen is available to mix with fuel, resulting in a more powerful combustion event.
How to Improve the Evo X Intake Manifold
While the stock manifold is competent, it is built for a compromise of street manners and cost. For modified engines, especially those running higher boost levels, it becomes a bottleneck. Here are the primary ways to improve it:
- Porting and Polishing: This is the process of meticulously enlarging and smoothing the manifold’s internal passages, particularly where it mates with the cylinder head (the ports). Removing casting flaws and matching the ports to the head reduces turbulence and improves airflow. Gasket matching ensures a seamless transition for incoming air.
- Aftermarket Manifold Upgrade: For serious builds, a fully aftermarket intake manifold is the ultimate solution. These are often designed with a larger plenum volume and shorter, wider runners optimized for top-end horsepower. They are typically constructed from billet aluminum, which allows for sharper turns and smoother internal surfaces than casting. Some feature velocity stacks inside the plenum to further improve airflow.
- Plenum Spacers: A more budget-friendly modification is a plenum spacer. This is an aluminum plate installed between the manifold and the cylinder head. It effectively increases the plenum volume, which can help reduce air turbulence and improve throttle response, particularly in the mid-range RPM band.
The Performance Impact
So, what happens after an upgrade? The impact is significant and measurable on a tuned car.
· Increased Horsepower & Torque: The core benefit is increased airflow, which allows the engine to produce more power, especially in the higher RPM range where the stock manifold can become restrictive.
· Improved Throttle Response: Smoother, less turbulent airflow means the engine can breathe more effortlessly, translating to sharper and more immediate response when you hit the accelerator.
· Unlocking Tuning Potential: An upgraded manifold removes a critical airflow restriction, allowing your tuner to safely maximize boost and ignition timing for greater gains from other supporting modifications.
For the Evo X enthusiast, the intake manifold is far more than a simple aluminum casting. It is a gateway to superior airflow, sharper response, and serious horsepower gains. Whether you opt for precision porting or a full aftermarket replacement, enhancing this vital component is a proven step toward dominating both the street and the strip.
Top Brands for Evo X Intake Manifolds: Choosing the Right Upgrade
Once you’ve decided to upgrade your Mitsubishi Lancer Evolution X’s intake manifold, the next critical step is choosing the right brand. The market offers options ranging from budget-conscious porting services to elite, race-ready billet pieces. Here’s a breakdown of the most reputable brands and what they bring to the table.
- Magnus Motorsports
The Benchmark for High-Horsepower Builds If you’re pursuing serious power(500whp and far beyond), Magnus is often the first name that comes to mind. Their famous V3 Street unit is an engineering masterpiece. CNC-machined from billet aluminum, it features a massive plenum and optimized runner design to support immense airflow demands. The V3 is legendary for shifting the power band higher, unleashing staggering top-end horsepower that the stock manifold could never facilitate. It’s the go-to choice for built motors and large turbo setups.
- AMS Performance
Renowned for OEM+ Quality, AMS is an Evo industry leader, famous for its race-validated, high-quality products. This AMS upgrade is a modified, direct-fit, cast aluminum component. It undergoes extensive porting, polishing, and milling to significantly improve flow over the stock unit while maintaining excellent drivability. For owners who want a substantial power increase without the extreme price tag of a full billet manifold, the AMS offering is a perfect and very popular balanced choice.
- STM
The Value Leader with Proven Results STM(Simple Turbo Maintenance) offers an excellent ported and polished OEM intake manifold. This method ranks among the most economical paths to enhanced performance. STM takes your stock manifold, aggressively ports and polishes the runners, and performs a “plenum hog-out” to enlarge the chamber. The result is a significant improvement in airflow and power, especially when paired with other boltons, for a fraction of the cost of a new manifold. It’s ideal for the enthusiast on a budget who wants to eliminate a major restriction.
- DCI Motorsports
