Why is the CFM+ the ultimate intake manifold?
Regardless of which tuner, air filter, exhaust system or aftermarket intake you may already have, you need to dramatically increase your airflow. No other aftermarket intake comes close. Even without a computer its easy to see why CFM+ flows so much better than the angular stock aluminum manifold with its nearly 40% flow restriction of the front mounting bolts.
Why does the CFM+ flow so much more air?
So why does CFM+ flow so much more air than any other oversized cast aluminum manifolds in the market and maintain lower air temps?
1. The very large center section of the competitors cast aluminum manifold may look impressive, but it is very bad for flow. The inlet to the manifold from the intercooler and the outlet of the intake manifold into the engine are very similar in cross sectional areas. When the center section is over three times larger than the inlet and outlet the air flow slows dramatically through this center section. The air flow then is forced to speed up to exit. This causes turbulence in the flow, leading to pressure drop or pumping losses.
2. The competitor’s manifold is so oversized in the center section that 2 of the mounting fasteners which hold the intake to the engine had to be changed to long bolts or studs that must pass directly through the air flow. (Figure 2) This causes tremendous turbulence in the flow leading to additional pressure drop or pumping losses.
3. You can also see in the picture of the cross section of the competitor’s aluminum manifold there are 2 surfaces (figure 2) protruding down into the flow path that creates recesses into the outside surface of the manifold. These pockets allow the mounting nuts to look good recessed on the outside but can cause a big problem on the inside where it matters (Figure 3).
These two surfaces protruding into the air flow act to trip up or tumble the airflow. Again this causes additional turbulence in the flow leading to pressure drop or pumping losses.
4. Cast Aluminum has a much rougher surface than the advanced technology composite CFM+ manifold. The rough interior surface of the competitors cast aluminum manifold causes additional turbulence.
CFM+ 44% increase air flow over Stock
CFM+ 20% increase air flow over completion
5. The volume of air that can get stuffed in to the engine is also greatly affected by the density of the airflow. This is why the material the manifold is made of is so important. If the manifolds material acts to insulate the hot under-the hood air from reheating the air flow that has just come out of the intercooler that is a very good thing for maintaining air density but if the material readily conducts heat such as aluminum that would be bad since the hot under-the-hood temps would raise the air entering the engine. Since under-the-hood temps are by definition higher than ambient or outside air temps and heat flow is always from high to low temps, a materials ability to allow heat to pass through it is called the Thermal Conductivity represented by “k” in engineering equations. Aluminum has a Thermal Conductivity rate or “k” of 236 W/M-?k. The CFM+ composite materials Thermal Conductivity rate is 0.25 W/M-?k which is 944 times lower.
Also the oversized cast aluminum intakes present more aluminum surface area that absorbs more under-the-hood heat and transfers it into the air flow.
Finally, CFM+’s advanced engineering composite material is high strength, high temp, & durable. Bottom line, we don’t do tuners, air filters, or exhaust systems. But what we do is engineer, design and manufacture the ultimate intake for the Cummins Diesel and Ford PowerStroke.