A Double Whammy: Combining a Supercharger and Turbocharger

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Gary Lieber

February 17, 2026

Gary Lieber

February 17, 2026

There’s a new emerging class of small but potent powertrains that deliver great performance and excellent efficiency. One strategy that makes this possible is twincharging: using both a supercharger for low-end performance and a turbocharger for high-RPM boost. A shining example of this two-prong approach can be found in the 2017 Volvo S90 sedan. The T6’s 2.0-liter 4-cylinder engine—which might otherwise be mild—produces an impressive 316 horses and 295 pound-feet of torque using supercharging and turbocharging.

The 2017 Volvo S90 uses twincharging. — 2017 Volvo S90 sedan

Volvo was not the first to introduce twincharging. The Lancia Delta S4, a Group B rally car, is a rare early example. Produced in 1985 and 1986, the Delta S4—commonly known as “Stradale”—uses supercharging at low RPMs. When the turbo spools up, a bypass valve disengages the supercharger, and the turbo then provides boost at higher RPMs. The four-cylinder car could produce about 480 horsepower.

The ultra-rare twincharged Lancia Delta S.

Only about 200 of these were built.

What does these cars reveal about the ability of those two forced-air methods about each one’s advantages and disadvantages? Should you consider combining the two?

Superchargers for Low RPMs

The Volvo S90's four-cylinder engine is boosted by both supercharging and turbocharging.

Superchargers are engine-driven blowers that boost power by improving air flow. There are several types of superchargers - opens in new window or tab., with the most popular being the screw-type.

Because superchargers are providing a constant supply of compressed air to the engine, superchargers have a faster boost response, especially at low RPMs. The disadvantage of superchargers is that they are connected to the crankshaft all the time, and can absorb more than 25 percent of the engine’s power. But what’s important is the net gain in power—and a supercharger’s ability to boost horsepower by as much as 200 percent yields an overall improvement by as much as 150 percent.

Superchargers can be directly connected to the engine, replacing the intake manifold with the fuel system on top of the supercharger, or can be externally mounted, supplying a compressed stream of air to the engine and fuel system. As compressing air also increases its temperature, which decreases its density, look for superchargers that include a radiator called an intercooler - opens in new window or tab. to reduce the air temperature. Most supercharger kits - opens in new window or tab. offered today integrate the compressor and the intercooler into one component that replaces an engine’s intake manifold.

supercharger-kit-800 — A Whipple supercharger kit for a Ford Mustang

Turbochargers for High RPMs

Turbochargers use an engine’s exhaust gasses to power a turbine that uses the energy of the still expanding exhaust gasses to power an air compressor—which in turn forces air into the combustion chamber. Turbos are more efficient than superchargers because they don’t put a direct load on the engine. Turbos also heat the compressed air charge, so they also need an intercooler.

A turbo’s disadvantage is that takes time to reach optimum performance or “spool up” to full capacity. In other words, it doesn’t provide immediate power. This lag time can be minimized by making the turbo lighter, smaller, by using low-friction bearings, or employing a twin-scroll (divided) design. Turbocharger kits - opens in new window or tab. offer a variety of configurations including second or compound turbochargers.

Put the Two Together

Volvo’s T6 motor uses a supercharger to provide low-end torque and responsiveness, and the turbocharger to add horsepower at the high end. “The biggest issue was to get the turbocharger and supercharger union to work together with refinement,” said Anders Robertson, head of Volvo’s S and XC 90 product development. “The units themselves are simple, but control, noise, vibration and harshness were the big challenges.”

“The T6’s engine management computer balances both systems with the supercharger’s boost set close to the engine’s intake system for low-end grunt and quick response below 3,500 RPM,” Robertson said. “The supercharger also spools up the turbocharger and then uses an electric clutch to disengage when the turbocharger takes over at higher RPMs. This clutch eliminates the superchargers load on the engine when it isn’t needed and a butterfly valve directs the optimum airflow between the supercharger and turbocharger.” With these technologies, Volvo has made combined the fuel economy advantages of a small displacement engine with a fat power band of a bigger engine.

While it’s tempting to try this double-whammy at home, it’s not recommended.

camaro-twincharge-800 — A home-brewed twincharged 1969 Camaro SS using twin turbos, a supercharger, and a 200-shot of nitrous. (Photo courtesy of ScottieDTV.com)

There aren’t very many off-the-shelf kits that combine both superchargers and turbochargers - opens in new window or tab.. That’s due to the complexity of directing the intake air between the supercharger and turbocharger, as well as being able to smoothly engage and disengage the supercharger based on the engine demands. This combined upgrade is usually reserved for drag-racers—a challenge beyond most daily drivers.

Nonetheless, we can respect the engineering accomplishments brought to the market by Volvo, and any gearhead willing to push performance to the limit with twincharging.

About the author

Gary Lieber

Gary Lieber is a regular contributor to the eBay Motors Blog, Clean Fleet Reports, and MyRideIsMe.com. His Porsche 911 is a multiple Concours winner including Top 911 at Porsche Parade in 2005 and 2015. His Volkswagen GTI has been tricked out with engine management upgrades and style enhancements not commonly available on this side of the pond.

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This article is meant to provide general guidance only. Automotive maintenance, repair, upgrade, and installation may depend on vehicle-specifics such as make and model. Always consult your owner's manual, repair guide for specific information for your particular vehicle and consider a licensed auto-care professional's help as well, particularly for advance repairs.