A TWOFOLD COOLING SYSTEM
Like the Maranello works outfit and US newcomers Haas, Sauber uses the Ferrari 059/5 power unit (Toro Rosso runs the late-2015 engine specification). The Ferrari intercooler used to sit within the ‘Vee’ of the engine; it has been replaced with two smaller elements: one air-to-air intercooler that basically sits on top of the gearbox, and one air-to-water device lodged within the chassis, at the back of the monocoque and behind the driver. This means the cooling process on the Ferrari power unit involves two steps. The airflow first goes through the air-to-air intercooler (see #1 on the drawing above); it is then channelled through a big tube before it reaches the air-to-water intercooler (see #2).
One might wonder why Maranello’s engine engineers have decided to come up with such a complicated design. While having the intercooler in between the two cylinder banks was ideal to obtain a tight package, this setup did not allow for the variable inlet trumpets seen on all other V6 turbos last year. In the end, the intercooler had to be moved somewhere else. Ferrari could have placed it in the sidepods, either as a single element like McLaren or by using a split-intercooler design in a manner similar to Red Bull. Instead, the Italian engineers have gone for a double installation in order to clear the sidepods as much as possible and curb airflow resistance, which in turn limits drag.
Instead of placing the intercooler in the sidepods, the Ferrari engineers have opted for a double installation in order to free up as much space as possible in the sidepods
On the Sauber C35, the air-to-air intercooler has a trapezoidal form and is placed horizontally. It is interesting to note that the same device is positioned higher on the Haas VF-16, while also having more of a ‘V’ shape and sitting almost vertically since it connects very early with the internal duct.
On the Haas and Ferrari, it is the main airbox inlet that feeds air to the air-to-air intercooler, while on the Sauber this airflow comes from the two ear inlets located on each side of the main duct.
With the MGU-K now placed on the left hand side of the engine instead of at the back, the Sauber gearbox (also of Ferrari origin) has been slimmed down, which in turn has allowed for a tighter rear end on the C35.
