"Hairdryer effect" and aftermarket FMIC
Feb 16, 2007, 09:08 AM
#16
Running the compressor outside its efficiency islands is just operating it in an area of diminishing returns. The further outside that area one ventures, the more sharply diminishing said returns. At some point to the right of the map, there is a limit whereby the velocity of air entering the turbo goes sonic, and the compressor cannot flow any additional air mass regardless.
One negative aspect of running outside of the map is the fact that it spins the turbo outside its designed rpm. As for how much of an impact it has on turbo life, one can only guess. Many people don't realize that turbos don't go on forever. They wear out like everything else.
In reality, a compressor map only tells one side of the story. The pressure on the exhaust side, if great, drives the PR right off the top of the map. This is as much a limiting factor as much as the physical limitation of the compressor itself.
One negative aspect of running outside of the map is the fact that it spins the turbo outside its designed rpm. As for how much of an impact it has on turbo life, one can only guess. Many people don't realize that turbos don't go on forever. They wear out like everything else.
In reality, a compressor map only tells one side of the story. The pressure on the exhaust side, if great, drives the PR right off the top of the map. This is as much a limiting factor as much as the physical limitation of the compressor itself.
