How do superchargers regulate boost

Turbo boost controllers can continuously control the actual boost pressure by varying how much exhaust pressure bypasses the turbine reducing boost pressure where supercharged engines are fixed based on rpm and engine design due to the relationship of engine speed vs supercharger speed. Last edited: Apr 8, Vehicle: Maverick 2 door. Original V-8 3 spd std shift. Also a 72 one owner Sprint sporting a Windsor.

Just look at a GM supercharged Pontiac grand prix or bonneville with the 3. Mavman72 , Apr 8, Joe Dirt , Apr 8, This makes sense when you consider that airplanes spend most of their time at high altitudes, where significantly less oxygen is available for combustion.

With the introduction of superchargers, airplanes were able to fly higher without losing engine performance. Superchargers used with aircraft engines work just like those found in cars. They draw their power directly from the engine and use a compressor to blow pressurized air into the combustion chamber.

The illustration above shows the basic setup for a supercharged airplane. The biggest disadvantage of superchargers is also their defining characteristic: Because the crankshaft drives them, they must steal some of the engine's horsepower. A supercharger can consume as much as 20 percent of an engine's total power output.

But because a supercharger can generate as much as 46 percent additional horsepower, most think the trade-off is worth it. Supercharging puts an added strain on the engine, which needs to be strong to handle the extra boost and bigger explosions.

Most manufacturers account for this by specifying heavy-duty components when they design an engine intended for supercharged use. This makes the vehicle more expensive. Superchargers also cost more to maintain, and most manufacturers suggest high-octane premium-grade gas. Despite their disadvantages, superchargers are still the most cost-effective way to increase horsepower.

Superchargers can result in power increases of 50 to percent, making them great for racing, towing heavy loads or just adding excitement to the typical driving experience.

Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Under the Hood. Engine Performance. How Superchargers Work. Troy Coughlin, Jr. Many race cars have supercharged engines. David J. Supercharger Basics " ". Photo courtesy Muscle Mustang. The piston moves down. This creates a vacuum inside the cylinder.

The vacuum causes air at atmospheric pressure to be sucked into the combustion chamber. Roots Superchargers " ". You sometimes see a roots supercharger sitting on top of the hood of a drag car. Twin-screw Superchargers " ". Centrifugal Superchargers " ". Supercharger Advantages " ". Supercharger Disadvantages The biggest disadvantage of superchargers is also their defining characteristic: Because the crankshaft drives them, they must steal some of the engine's horsepower.

Supercharger FAQ How does a supercharger work? A supercharger pressurizes the air intake to above atmospheric pressure. It's similar to a turbocharger, but a supercharger is powered mechanically by a belt- or chain-drive from the engine's crankshaft. What is the difference between supercharger and turbocharger?

The difference between a supercharger and a turbocharger is the devices' source of energy. Turbochargers are powered by the mass-flow of exhaust gases driving a turbine. Superchargers are powered mechanically by a belt- or chain-drive from the engine's crankshaft.

How much horsepower does a supercharger add? A supercharger can boost a vehicle's engine output between 30 and 50 percent, but it results in a 46 percent increase on average. So, you can expect to see your horsepower to increase accordingly. How much faster does a supercharger make your car? A supercharger won't necessarily make your car faster, but it can benefit acceleration. Are superchargers worth the money? Superchargers do have advantages. They can increase your engine's horsepower, and they can make your vehicle perform like it has a larger, more powerful engine under the hood.

But there are disadvantages too, like increased output consumption and added engine strain. Sources Autocar. April 27, Supercharger: What's the Difference? March 24, Because of this external compression nature, Roots-type superchargers produce more heat in the inlet air charge than either of the other styles of supercharger, and therefore the Roots-type design is considered to be the least efficient of the three main styles available. For example, 1psi boost from a Roots-type supercharger will be hotter, and therefore less dense, than 1psi of boost generated from a centrifugal or twin-screw supercharger, and will therefore make less power.

But of course, this can be negated by the use of a heat exchanger or intercooler setup. However, Roots-type superchargers do have their advantages. Reliability is probably the biggest of which, and is certainly one of the main reasons Roots-type superchargers are used in OE production cars.

Because it is a simple design, there are few moving parts, and those moving parts are moving relatively slowly remember a turbocharger spins at over ,rpm! Roots-type superchargers are incredibly durable and require very little maintenance. A Roots-type supercharger will also give you positive boost pressure from the moment you open the throttle the amount of which will depend on the size of the pulleys used to drive, and therefore the speed of, the rotors , and will give you everything it has to offer at full throttle, regardless of engine speed.

Therefore Roots-type units are really well suited to smaller capacity engines that generally struggle to make power in the lower rev range, but also to drag cars that require full power and torque at lower rpms to help get off the line as fast as possible.

A centrifugal supercharger is very similar to a turbocharger, but rather than having an exhaust housing with a turbine wheel being driven by exhaust gases, the supercharger has a pulley being driven by a belt from the crankshaft.

But the front end of a centrifugal supercharger is very similar to that of a turbo, from head-on they even look the same.

Both have a snail-like compressor housing often called a volute when referring to superchargers with an inducer wheel impeller that draws air in through the front of the unit, before throwing it outwards into the scroll of the compressor housing. The scroll acts as a chamber to collect the air and channel it towards the engine intake, and is designed so that the diameter increases as it moves further away from the centre of the housing.

In doing so the flow of air slows down as it exits the scroll, but at the same time its pressure is increased — this is how we end up with positive boost pressure exiting the unit.

However, in order to do this the inducer needs to spin incredibly fast, just as it does with a turbocharger. To allow this, the belt-driven pulley found at the back of the unit is attached to a large gear, which in turn is meshed with a much smaller gear attached to the inducer wheel.