Here's a breakdown:
* A/R: This is a ratio between the area of the turbine housing's exhaust outlet and the area of the turbine wheel's inlet.
* Area: This refers to the cross-sectional area of the respective openings.
* Ratio: The ratio expresses how much larger the exhaust outlet is compared to the turbine wheel inlet.
What does the A/R ratio affect?
The A/R ratio plays a crucial role in turbocharger performance by influencing:
* Boost response: A smaller A/R ratio (smaller outlet area) provides quicker boost response but limits the potential for maximum boost pressure.
* Maximum boost: A larger A/R ratio (larger outlet area) allows for higher boost pressures but delays boost response.
* Exhaust flow efficiency: A smaller A/R ratio can restrict exhaust flow, while a larger A/R ratio can allow for more efficient exhaust flow.
Choosing the right A/R:
The ideal A/R ratio depends on the specific application and desired performance characteristics. For example:
* Street cars: Often prefer a smaller A/R for quick boost response and better drivability.
* Racing applications: Might choose a larger A/R for higher boost and maximum power.
Examples:
* AR .63: A smaller A/R ratio known for quick spool-up and good response for street driving.
* AR .82: A larger A/R ratio for higher boost potential, often used in racing or high-performance applications.
Remember, selecting the right A/R for your turbocharger is important for optimizing performance and ensuring efficient operation.
