Forced induction. You hear about it. Superchargers, Turbos, Ram Air… these are all forms of FI or Forced Induction. I’m not going to get into SUPER details here, just the basics.
I WILL NOT be discussing Nitrous Oxide in this post, as there is a complete topic about it in The Domestics Lounge
The Basics: What is forced induscion?
Well, it is any manner of forcing air into your engine, rather than letting it come in on its own. Hence, the name, forced induction. It is important to realize that ANY car can be converted to forced induction… this isn’t reserved for strictly cars that were FI from the start. N/A or Natural Aspiration is what most cars are from the factory. The engine just kind of sucks in the air it needs, which will keep your Volumetric Effiency or VE below 100%. However, with FI, VE’s of over 100% are possible.
How it effects your engine: It is kind of like adding compression, except more efficient. You may need to retard your timing, and will need to run a higher octane gas to prevent detonation. It is also just as important to make sure you get cams to suit your needs. You will need extra fuel to compensate for all the extra air coming in, which may require more than just standard injectors. In other words, FI is not an easy conversion. But here’s the basics.
Superchargers: Superchargers are one of the most commonly used forms of FI. Superchargers use a belt-driven impeller (or screw-type impellers for roots type) to push air into the engine based on engine speed. You can increase the amount of pressure by using a smaller pulley on the supercharger, or a larger pulley on the crank. Superchargers are best used for low- to mid-range power boosts, as they lose efficiency quickly in high RPM use. Also, since they are crank driven, they use power to make power, so they are not 100% efficient. But since they are crank driven, they are always making boost, and always making power.