Originally posted by rac74:
Originally posted by DemonSVT:
392cfm draw at 7500rpm??? Not on any NA engine that fits in our car.



I just used the formula from from your site(CIDxRPM/3456), guess it's not to great for real world purposes.


That formula does not factor in volumetric efficiency. Well more accurately it states the VE as equal to 100% for ease of calculation. (it's part of the air filter sizing section)

The VE of a DOHC engine is normally in the 85-95% range. Countless things effect the engine's VE hence why I gave a basic range of cfm flows for engines of the same displacement. For instance the stock cams vs the SVT cams. The SVT cams have a significant VE advantage in the higher rpm range so holding a higher percentage will make a larger difference in the natural cfm pull since rpm is a factor. A VE increase equals a torque increase and HP is just a function of torque and rpm.

2000 SVT #674 13.47 @ 102 - All Motor! It was not broke; Yet I fixed it anyway.