How it's built · 1 min

What a turbocharger actually does

A turbocharger is one shaft. Exhaust spins a turbine. The compressor on the other end packs intake air. The wastegate is a bypass around the turbine, not the turbo.

People treat this like a bolt-on blower. Or like the wastegate is the turbo. It is neither. A turbocharger is one shaft. Exhaust spins a turbine. The other end packs intake air.

Sectioned Garrett turbocharger, yellow turbine and compressor wheels on one shaft, red-painted cut housings
Photo: Tommi Nummelin.

The hot wheel lives in the exhaust. Gas hits those blades. The shaft turns. The cold wheel in the intake stuffs more air into the manifold. More air, more fuel the box can burn. That is the job: leftover exhaust energy packing the intake. The cartridge in the middle is the CHRA — shaft, bearings, both wheels. The snails are housings.

Garrett GT30 on a bench, aluminum compressor housing over a dark turbine housing, oil line on the center
Photo: Freonr2.

The wastegate is a door around the turbine. When it opens, some exhaust skips the hot wheel and dumps into the downpipe. That is a bypass, not the turbo. Do not start at the little can on the compressor housing because someone said turbo. Start at the shaft that has a wheel at each end.