Reply to "Looking for tall velocity stacks"

Answers to your qustions as I understand:
The Ferrari Boxer suffered from a loss of power (and valves) at very high speeds due to their Pantera-style decklid creating a swirl over the back end of the car. In the Ferrari, the carb air intakes were at the back edges of the decklid. At speeds above about 160 mph, the aero-swirl moved past the end of the decklid, leaving the air intakes running in a partial vacuum. The mixture went lean and much damage followed. The 'Boxer slat' modified the swirl such that the intakes continued to get air up to some much higher speed. Ferrari also later went to EFI, which may have been less speed-sensitive; dunno.

Mounted on a Pantera, the slat works nicely as a sunshade. Speculation is that in combination with a wing or ducktail spoiler, the Boxer-slat MAY make them more efficient, but to my knowledge, no one has ever actually tested this theory. Few consistently run their Panteras above 170 for more than seconds- if that.

This is the story of the blue car of Dennis Antennucci, as I remember him telling it. It ran stock cast-magnesium Campagnolo wheels, and due to a maintenance error by his mechanic, a bolt holding a stock rear caliper came loose. This allowed the iron caliper to move & drag on the inside of the magnesium rim. Enough friction heat was generated during a 92-mile Open Road event at speeds up to 170mph, that the right wheel ignited. A cover photo in Autoweek magazine showed the car crossing the finish line at a clocked 170+ while trailing a sheet of flame. The firemen at the event were untrained in dealing with burning mag, so when they sprayed the fire with water, the burning mag reacted to form hydrogen and oxygen, became far worse and the car subsequently burned to the ground with everyone watching from a safe distance. A year or so later, the entire car was completely restored and ran Open Road events again for at least a dozen more years with only small problems. Dennis still has his ol' blue car which looks pretty good for the life its led.