http://www.hobracing.com/tech/tpi_flow.asp

Re: bases/runners

Personally dont buy it. Anyone else yay or nay?

When flowing at 28 in you get a more accurate #.
If say someone flows (which is common) at 10 in and uses a correction factor for 28 the # will appear sometimes much higher than the piece can actually flow.
Next time you pay to have something done, ask how they do it.

All Im sayin is if you see a part thats +-xx amount take it with a grain of salt. Method and machines can really vary.