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Intake manifold choice is usually based on the application it’s being bolted to and there are a lot of options out there you can choose from — everything from off-the-shelf stock intakes to exotic fabricated units are available, but what do you really need? Every intake is a bit different and how your engine will react to the air it brings in will dictate what you need. CFE Racing Products [2] shares some of their knowledge with us about when you need to look at a cast intake versus a fabricated intake.
There’s no reason to make the process of sourcing an intake too complex; for many racers, the simplicity of using a cast intake is all they need to get the job done. The level of engine performance plays into what intake you’ll need and should help in the decision process. Engines that are making under 1,000 horsepower naturally aspirated will do just fine using a cast intake.
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According to Scott Kieffer from CFE, the space required to package everything needed can impact the intake choice you make, and why some simply have to go with a fabricated intake. “You have to look at what needs to go into the package, especially with boosted applications. It’s all about fitting things under the hood and accessorizing the manifold with EFI or bosses for added injectors. The same goes for nitrous. Speaking generally, the larger the manifold is, the more room you have to package more nozzle bosses.”
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Where cast intakes work so well when you need something simple, a fabricated intake should be used when there’s specific and custom needs in mind. “If we’re building something as opposed to working within the boundaries created with an existing cast piece, we can tailor the runner lengths around the combination based on our experience. We have the ability to alter throttle body or carburetor mounting position for either packaging reasons or improved performance. The plenum size and runner positions can be manipulated on a fabricated intake for better distribution. We can also build something that suits the deck height without the need for flange spacers that create additional sealing surfaces,” Kieffer says.
Intake choice comes down to your application and performance goals. There’s no need to over think things if you are trying to only make a certain level of power, so the cast style intake might be the best choice for you. For those that are trying to rotate the earth with power, it’s time to step up to a trick fabricated unit like the ones CFE Racing Products offers.