You might call it a plenum, or a collector. Since its pre throttle body, its not really an intake manifold.The Nismo plenum helps to balance airflow between the six cylinders in an RB 26. The first 5 cylinders have bellmouths, but #6 the highest flowing, and generally leanest hole, does not.
Collector volume: 4.1 liter (genuine = 3.4 liter)
Intake pipe length: 73.8mm (genuine = 48.5mm)
Intake pipe diameter: tapered from 43 to 45 (genuine = 45)
Material: cast aluminum
- Intake temperature difference at the entrance of turbo chargers is improved averaging 18% in 2, 400 to 7, 600 rpm range.
- At 4, 800 to 7, 600 rpm, power output is increased by an average of 1.8%, while fuel economy is improved averaging 0.4%.
- This product cannot be installed with the engine mounted.
- Installation of this product will change the characteristics of the engine, necessitating adjustment of the engine control unit. Failure to do so very likely will result in damage to the engine.
- The engine improvement figures shown above are based on internal company testing. The actual level of improvement will depend on the engine specifications, conditions of air-fuel mixture and ignition timing, weather and the precision of measurement.
- This product cannot be used with single, large-diameter throttle chambers.
To find the most suitable shape for tuning engines (400ps to 600ps), the diameter and the length of the intake pipe, and the cross section shape of the intake collector was redesigned. The distribution of air to each tube was improved to provide more equal airflow volume, improving torque in the mid-speed range. Improved air intake volume between the pipes of the front and rear sides reduces the difference in air intake temperature on both sides of the turbine, optimizing the air-fuel ratio and ignition timing and providing increased output and fuel consumption. Simple bolt-on installation means that no additional work is required (however, the throttle linkage and throttle sensor must be adjusted).