So much of making power is about airflow.
Every internal combustion engine has an optimum combination of intake and exhaust length for torque and for horsepower. They’re infinitely variable – to make horsepower, as you come up the the rev range, you want to shorten the intake, and lengthen the exhaust.
For decades, engineers settled for the perfect compromise between peaky horsepower, and low-end drivability. But in the 1990s, interesting things started to happen: engineers were figuring out how to allow sports car buyers to have their cake and eat it too.
Take this Ferrari 360. A lot of the wizardry that allows this 3.6 liter flat-plane crank V8 to make 400 horsepower happens in this intake manifold.
You’ll notice that the runners go straight up and down: Air and fuel goes straight down into the cylinder, providing the best flow. Inside, there are effectively eight openings for each bank of cylinders — 16 in all. Which opening is feeding the cylinder is based on the needs in that moment.
To make horsepower, it’s a shorter path — the plenum opens. For torque, it blocks off opening, forcing a longer path in the runner.
In addition to variable exhaust exhaust cam timing, Ferrari optimized the way the intake works.
Porsche used a similar technology, called VarioRam, which debuted on the 993 in 1996.
The late 1990s early 2000s were a special time for naturally-aspirated engines. These intake techniques were essential for achieving the high specific output of horsepower to displacement.
At Modern Aircooled, we’re geeks for this stuff, and we love celebrating and marveling at the ingenuity that went into these special cars and technologies every time they come into the shop.