abv

Ok smart people....

flow bench testing....is this like dyno testing in the sense taht different people can get different results by:

1. using different equipment to test flow
2. different operators of the equipment

and are there different settings (pressure etc...) that cn manipulate the results?

thanks

snakeeater

The flow bench has a fan that blows air through the port in your head. There is an instrument measuring air flow that is recorded to document gains from porting. But for any flow reading (cfm) to mean anything, you must know the test conditions. The flow bench has a regulator valve to limit the incoming pressure of the air that is being forced into the port. The differential pressure needs to be stated (in inches of water usually) in order to qualify the flow number. Most tuners use a fairly standardized value that accurately represents the manifold pressure at WOT.

But not everyone will use the exact same diff pressure. That is why it is important to check. As an extreme example, someone could be turning the pressure regulator on the flow bench up to 10 psi of boost pressure and reporting huge flow numbers. Well they are huge, but only because you have so much boost pressure pushing the air flow. If boosting didn't increase flow noone would buy a turbo or supercharger. If you are assuming N/A, or you're comparing their flowbench numbers to another tuner who used a lower pressure, you will be misled into believing that the first tuners porting is superior.