Table of Contents
What is the advantage of a variable length intake manifold?
As the name implies, VLIM/VIM/VIS can vary the length of the intake tract – in order to optimise power and torque across the range of engine speed operation, as well as help provide better fuel efficiency.
What happens when you increase length of intake runner?
The length of the intake runners have certain affects on the engine operation. For example, longer intake runners are used to improve the bottom end torque (torque at low RPMs) while shorter intake runners will improve top end power (horsepower at high RPMs).
What is BMW DISA?
The BMW Differentiated Intake System, known as DISA (from the german “DIfferenzierte Sauganlage”, means differential air intake), optimizes the engine’s running under partial and full load as it adjusts the intake manifold runner length to improve engine performance.
Is longer intake manifold better?
Longer intake runners are usually associated with better top end performance at higher rpms. Those longer runners as shown may deliver benefits from being able to perhaps take in more and cooler air than if closer to the engine as opposed to better flow.
Does length of intake matter?
The results revealed that, for low engine speeds, the intake pipe with longer length and smaller diameter produced the best performance. On the other hand, the intake pipe with shorter length and larger diameter delivered the best engine performance at high speeds.
How much HP can a intake manifold add?
Depending on your make, model, engine size, and type of intake, truck owners can expect an increase of between 5 and 15hp.
What is variable intake manifold system?
The air required for combustion in the engine flows through the variable intake manifold to the intake valve. Nowadays, common fuel injection systems for petrol engines inject the fuel in the intake manifold immediately prior to the intake valve.
How long do DISA valves last?
The DISA valve will normally only last 70,000-100,000 miles. We highly recommend replacing it or rebuilding it at this mileage to prevent any catastrophic failures.
How much hp does a Skunk2 intake manifold add?
Skunk2’s Pro Series Intake Manifold = 17whp and 10 lb-ft torque peak gains when compared to Honda’s RBC manifold.
How does a variable length manifold work?
The variable length runner manifolds use a valve to switch back and forth between two runners depending on what the situation calls for. When the engine load is high (low RPM), the manifold will switch to use a longer, smaller runner to get the low end torque.
When was the first variable length intake manifold patented?
The first patent issued for a variable length intake manifold was published in 1958, US Patent US2835235 by Daimler Benz AG. There are two main effects of variable intake geometry:
What is the difference between intake manifolds and runners?
When the engine load is high (low RPM), the manifold will switch to use a longer, smaller runner to get the low end torque. When the engine load is low (high RPM), the manifold will switch to use a shorter, bigger runner to help with power on top. The best of both worlds. Disclaimer: This is a simplified explanation of intake manifolds and runners.
What does the length of an intake runner matter?
For example, longer intake runners are used to improve the bottom end torque (torque at low RPMs) while shorter intake runners will improve top end power (horsepower at high RPMs). The lengths will vary from engine to engine as well as what the goals of each vehicle the engine will be powering.