There comes a point in every build where naturally aspirated horsepower just isn’t enough. You want the tires to break loose at 60 mph. You want that sound. You need boost.
Forced induction is a simple concept: an engine is just an air pump. The more air and fuel you can cram into the cylinders, the bigger the explosion, and the more horsepower you make. But how you choose to force that air into the intake—either with a turbocharger or a supercharger—completely changes how your car drives, sounds, and launches.
Here is the no-nonsense breakdown of the two heavyweights of horsepower.
The Supercharger: Instant Gratification
A supercharger is essentially an air compressor bolted directly to the top or front of your engine. It is driven by a belt connected right to the engine’s crankshaft. As soon as the engine spins, the supercharger spins.
The Pros:
• Zero Lag: Because it’s driven by the engine belt, the power is instantaneous. The second you smash the gas pedal, you have full boost. It makes a car feel like it has a massive big block under the hood.
• The Sound: Nothing on earth sounds like the screaming whine of a Roots or Twin-Screw supercharger at wide-open throttle.
• Easier Plumbing: You don’t have to fabricate a maze of custom exhaust pipes. You bolt it to the intake manifold, put a belt on it, and tune it.
The Cons:
• Parasitic Loss: It takes horsepower to make horsepower. Because it runs off a belt, the engine actually has to work hard just to spin the supercharger. You might lose 50 to 100 horsepower just turning the blower before you see any gains at the wheels.
• Hood Clearance: Say you’re staring down the engine bay of an ’86 Grand Prix and decide to drop a blower on top of your V8. Unless you want to cut a massive hole in your hood, fitting a top-mount supercharger under classic sheet metal can be a nightmare.
The Turbocharger: Free Energy
A turbocharger doesn’t use a belt. Instead, it uses the hot exhaust gases blowing out of your engine to spin a turbine wheel. That turbine is connected to a compressor wheel on the other side, which sucks in fresh air, compresses it, and shoves it into the engine.
The Pros:
• Massive Power Potential: Turbos are wildly efficient because they run on exhaust gas that was just going to exit the tailpipe anyway. They don’t rob power from the crankshaft. Pound for pound, a turbo will almost always make more peak horsepower than a supercharger.
• Adjustable on the Fly: With a turbo, you can use an electronic boost controller. You can drive to the grocery store on 5 pounds of boost, then push a button at the drag strip and run 15 pounds.
• The Sleeper Look: Turbos can be tucked down low and hidden. You can pop the hood and look completely stock to an untrained eye.
The Cons:
• Turbo Lag: Because a turbo relies on exhaust gas to spin up, it takes a second. You hit the gas, the engine revs, the exhaust builds pressure, the turbo starts spinning… and then the power hits like a freight train.
• The Fabrication Nightmare: A turbo setup requires a massive amount of custom plumbing. You need a “hot side” (custom exhaust headers routing to the turbo) and a “cold side” (piping running from the turbo, to a front-mounted intercooler, and finally to the engine). It gets crowded, hot, and expensive very fast.
The Verdict: Which one is right for your build?
It comes down to what you want the car to do.
If you want a street brawler that shreds tires from a stoplight the instant you hit the gas, and you want that classic muscle-car whine, get a Supercharger.
If you want to dominate on the highway, chase maximum horsepower numbers on the dyno, and love the sound of a blow-off valve between gears, grab the welder and build a Turbo kit.
Either way, you are going to need wider rear tires.