[snowman]

Maybe he didn't know about it or didn't want to tell. I got the tip from one of the preeminent cam grinders with a whole lot of Porsche experience. I also got over 145hp on the ground with my 912. The guy does tell others but only after they meet certain conditions of his so I will not repeat his name without his permission.

The info also makes a lot of sense. With proper tuning you should have at least 110 percent the cylinder charge waiting in the intake or it (ram charging) just can't happen. A 356 is very simple as each intake runner is independent and there is no plenum. The biggest problem is the intake size varies along the way and it contains fuel as well as air. Calculations that do not take these things into account do not work. The combustion chamber is also the bathtub type which has a dramatic effect on the parameters. So you go with what a million people have already done, and it works.

As to why it works, its simple to visualize in the frequency domain, (rpm). Each firing of a cylinder is an impulse. If you look at an impulse in the frequency domain you see a sin(x)/x presentation for each bang. Since there is a series of bangs you can line up the sin(x)/x waveforms next to each other. If everything is right the side lobes of the waveform can add or subtract from the adjacent ones. If they add you have what we want and ram tuning. Very easy to visualize in the frequency domain, very hard to visualize in the time domain. That’s the power of higher level math. This representation also shows why there are multiple solutions, and why they are not as good as the fundamental one.