Let me try to understand this??
We take a static flowz measurement of the ex port at peak lift, with some sort of short pipe on it (or maybe no pipe) at a lift the engine will have at maybe 110* ECL or so, at one fixed depression of 28". We then divide that number by a static flowz test at a fixed depression of 28" of the intake, at a lift the engine will have at maybe 106* ICL with no manifold/carb etc. on (or maybe so), and the results of that math determine how much before BDC we will open the ex valve, and how long after TDC we will close it, and those ex open/close positions will be "as compared to in duration" or intake valve open/close that were based on what ? FlowZ????
Seems simple enough, just a couple questions??
How do you go about deciding the FIRST valve event??
Which one is first?
How do we decide the intake needs reduced, or ex needs more if ex/in flowz ratio is lower than "optimal" whatever optimal is ???
How do we decide the same thing if the ex/in flowZ ratio is higher than "optimal" whatever optimal is ??
How do we decide the intake is "good" and the ex is weak, or the other way around??
What's "optimal" flowZ ? I mean there's gotta be a standard to compare to for something to be weak or strong.
What do we do if bolting the intake on drops cfm by 25???
Does that count??
How about if a 1.8" primary tube flowZ more than a 1.75" tube on the flowZ bench, but the car is faster with the 1.75" header?
Do we add or reduce ex/in duration??