The RB25 intake manifold is designed to optimize airflow for efficient combustion, featuring a long-runner design that enhances low-to-mid-range torque. Some models include Nissan’s Variable Intake System (NVCS), which improves throttle response and power delivery. Upgrading to an aftermarket forward-facing plenum, such as those from Greddy, Plazmaman, or Hypertune, offers better airflow, reduced restrictions, and improved high-RPM performance. However, modifications may be required, including rerouting vacuum hoses, adjusting throttle body compatibility, and upgrading the fuel rail and injectors. While a shorter runner design enhances top-end power, it can slightly reduce low-end torque, making manifold selection crucial for specific performance goals.

Features

Long-runner design enhances low-to-mid-range torque.

Variable Intake System (NVCS) on some models improves throttle response.

Aftermarket options (Greddy, Plazmaman, Hypertune) provide better airflow and high-RPM performance.

Forward-facing plenums reduce restrictions and improve throttle response.

Requires modifications such as rerouting vacuum hoses and adjusting throttle body compatibility.

Fuel rail and injector upgrades may be needed for certain setups.

Shorter runner designs boost top-end power but may slightly reduce low-end torque.

Manifold selection should align with specific performance goals and engine setup.