Supercharger vs Turbo. The ultimate question in forced induction. People are often confused it’s better to go supercharged or better to go with a custom turbo kit or an off the shelf turbo kit. Both are different in terms of how they work, performance and cost.
Essentially, a turbo sits off of your exhaust manifold, and the exhaust gasses spin one end of the turbo (the exhaust side), which makes your compressor side spin also and force air into the intake system, therefore creating air pressure. A supercharger doesn’t work off the exhaust gas, it is attached to your engine and spins with the crankshaft. When the crankshaft spins the supercharger, it forces air into the motor. The turbo is more efficient as it doesn’t require engine power to spin it, so it makes more power per boost. A supercharger also does not create full boost until red line, which is when the engine is spinning the supercharger as fast as possible.
What is forced induction?
Both a turbo kit and supercharger are forced induction systems. They are designed to literally force air into your engine. The more air you can get into your engine, the more power your car will make.
What is a supercharger?
A supercharger is a unit that bolts to your engine and connects with a belt between your crankshaft and the supercharger unit. As the engine spins, it spins the supercharger and makes the supercharger force air into the engine. The size of the pulley that spins the supercharger determines how much boost you will make. A smaller pulley means the supercharger will spin faster so it will make more boost. The supercharger is limited by its efficiency, so if you over boost the supercharger, it will blow hot air into your engine and you will not make as much power (amongst a myriad of other problems). Since the engine needs to literally spin the supercharger, it is not as efficient as you need to use horsepower to make horsepower.
What is a turbo?
A turbo is similar to a supercharger, except it has an exhaust housing instead of a pulley and runs off of your exhaust gasses. As your car produces exhaust, the exhaust gas spins the turbine which causes the compressor to force air into the engine. A turbo is more efficient than a supercharger since your engine does not need to work harder to power the turbo. Because a turbo is not connected directly to the engine, it can spin much faster than a supercharger.
Is a turbo or supercharger smog legal?
There are far more smog legal supercharger kits than there are smog legal turbo kits. The reason is that the supercharger doesn’t have as much smog altering or modifying equipment such as a turbo usually. While a supercharger can have an inter cooler and blow off valve, it does not have a waste gate. These items can make your car or truck not pass smog and would need to be expensive to be done in an emissions friendly way, which makes them out of the budget for most people.