Turbo Comparison Specs

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Turbo Comparison Specs

Post by west_minist »

Turbo Trim.gif
Turbo Trim.gif (27.85 KiB) Viewed 8656 times

Trim is a common term used when talking about or describing turbochargers. For example, you may hear someone say "I have a GT2871R 56 Trim turbocharger".
What is 'Trim?' Trim is a term to express the relationship between the inducer* and exducer* of both turbine and compressor wheels. More accurately, it is an area ratio.

* The inducer diameter is defined as the diameter where the air enters the wheel, whereas the exducer diameter is defined as the diameter where the air exits the wheel.

Based on aerodynamics and air entry paths, the inducer for a compressor wheel is the smaller diameter. For turbine wheels, the inducer it is the larger diameter (see picture)

The trim of a wheel, whether compressor or turbine, affects performance by shifting the airflow capacity. All other factors held constant, a higher trim wheel will flow more than a smaller trim wheel. However, it is important to note that very often all other factors are not held constant. So just because a wheel is a larger trim does not necessarily mean that it will flow more.
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