NO MONKEY BUSINESS IN 2018

Force India mounted a new monkey seat on the rear crash structure of its VJM10, which lined up with the exhaust tailpipe. After Monaco, it is only the second time this year that the Y100 winglet has been added to the car. The Suzuka design looked different compared to the previous spec with the monkey seat framed by two winglets connecting to the rear crash structure. Force India must have found some substantial gains in running the element this year since the device will be banned from 2018 onwards.

At the back of a Formula 1 car, the rear wing and the diffuser are the two main components working with each other. Both guide the airflow upwards and in between sits the monkey seat, with current technical regulations allowing a piece of bodywork located at least 100mm either side of the car centreline. That’s why the monkey seat is also referred to as the ‘Y100 winglet’.

In order to understand the role of the monkey seat, one should understand what happens above the device, at the level of the rear wing. The latter has an optimum angle of incidence, beyond which the wing starts losing lift. If the wing is too tilted, a stall phenomenon can happen, i.e. the air flowing underneath cannot stay attached to the wing. The air then slows down and goes straight ahead, which means it no longer creates a low-pressure area.

Located above the exhaust, the monkey seat assists the rear wing in preventing the stall phenomenon. How so? In creating a depression zone above the exhaust, which sucks the gasses upwards and guides them under the rear wing. These gasses will then help the air flowing under the wing stay attached to it. That way, the rear wing can work in a stable manner while being at a high angle of incidence, which is necessary to generate aerodynamic load.

The FIA has been suspecting some teams to use engine mappings specifically designed to blow exhaust gasses towards the monkey seat, even when the throttle is not engaged. F1’s governing body is against the concept, which led engine manufacturers to develop bespoke engine mappings in the early 2010s when blown diffusers and Coanda exhausts were all the rage. Hence the 2018 technical regulations mandating the exclusion of any aero element in the area where the monkey seat is currently placed.