From Stock to Monster: Step-by-step Guide to Building a 400 Hp 4g63 with Garrett Gt35 Turbo

The 4G63 engine is a legendary power plant, known for its robust design and tuning potential. In this guide, we will walk you through the steps necessary to transform a stock 4G63 into a 400 horsepower monster using a Garrett GT35 turbocharger. This transformation involves careful planning, the right parts, and a commitment to quality work.

Understanding the 4G63 Engine

The 4G63 is a 2.0L inline-4 engine that has gained a reputation among car enthusiasts for its performance capabilities. Originally designed for the Mitsubishi Eclipse and other models, it features a DOHC configuration and is known for its durability. Before diving into modifications, it’s essential to understand its components.

  • Engine Block
  • Cylinder Head
  • Pistons and Rods
  • Crankshaft
  • Turbocharger System

Parts Needed for the Build

To achieve 400 horsepower, you will need several key components. Below is a list of essential parts for your build.

  • Garrett GT35 Turbocharger
  • Upgraded Fuel Injectors (1000cc recommended)
  • High-Performance Fuel Pump
  • Aftermarket Engine Management System
  • Upgraded Intercooler
  • 3-inch Turbo Back Exhaust System
  • High-Performance Camshafts
  • Upgraded Engine Internals (forged pistons and rods)
  • Adjustable Fuel Pressure Regulator

Step 1: Preparing the Engine

Before any modifications, ensure your engine is in good condition. A thorough inspection is necessary, and any worn components should be replaced. This will provide a solid foundation for your build.

Disassembly

Begin by disassembling the engine. Remove the intake manifold, exhaust manifold, and any ancillary components. Label all parts and take notes for reassembly.

Inspecting Components

Check the cylinder walls for scoring and the crankshaft for wear. Replace any damaged components to ensure reliability at higher power levels.

Step 2: Upgrading Internals

To handle the increased power, upgrading the engine internals is crucial. This includes installing forged pistons and rods, which can withstand higher pressures and temperatures.

Installing Forged Pistons and Rods

Carefully install the forged pistons and rods according to the manufacturer’s specifications. Ensure everything is properly torqued to avoid future failures.

Step 3: Turbocharger Installation

The Garrett GT35 turbocharger is a popular choice for achieving high horsepower. Proper installation is critical for performance and reliability.

Mounting the Turbocharger

Mount the turbocharger to the exhaust manifold, ensuring all gaskets are new and properly sealed. This prevents exhaust leaks that can hinder performance.

Connecting the Wastegate

Install an external wastegate if your setup requires it. This will help control boost levels and prevent overboosting, which can damage the engine.

Step 4: Fuel System Upgrades

With the increased air flow from the turbo, your fuel system must be upgraded to provide adequate fuel delivery.

Installing High-Performance Fuel Injectors

Replace the stock fuel injectors with high-performance ones rated at 1000cc or more. This ensures that the engine receives enough fuel at higher boost levels.

Upgrading the Fuel Pump

A high-performance fuel pump is essential to maintain fuel pressure. Install one that can handle the increased demand of your modified engine.

Step 5: Engine Management System

To properly tune your engine, an aftermarket engine management system is necessary. This allows for precise control over fuel delivery and ignition timing.

Choosing the Right EMS

Select an EMS that is compatible with the 4G63 engine and offers features for tuning and monitoring. Popular choices include AEM and Megasquirt.

Step 6: Final Assembly and Tuning

Once all modifications are complete, it’s time for reassembly. Carefully follow your notes and ensure everything is torqued to specifications.

Tuning the Engine

After reassembling, take the vehicle to a professional tuner. They will adjust the EMS settings for optimal performance and safety, ensuring your engine runs smoothly at 400 horsepower.

Conclusion

Transforming a stock 4G63 into a 400 horsepower powerhouse is an ambitious project that requires careful planning and execution. By following this step-by-step guide, you can achieve your performance goals while ensuring the reliability of your engine.