Renault has found a way to blow the exhaust gases for aerodynamic gains after a 20 cm wide wing, a popularly-called monkey seat, which could partially use this effect, was banned this season.
The exhaust gases were directed to the diffuser area between 2010 and 2013 in order to increase its aerodynamic efficiency, and the trend started in 2010 with Red Bull with its RB6. Sebastian Vettel and Red Bull have won four doubles in that four years, two dominant, and two in the final race of the season.
Rules changed before new hybrid turbo era in 2014 as the two exhaust pipes on each side were replaced by one central (and later two smaller on its side) whose position was strictly controlled to prevent teams from blowing into the diffuser area.
Renault recreated that aerodynamic effect of hot and fast exhaust gases but in the rear wing area. For this, the exhaust pipe moved maximum upwards, 550 mm above the reference plane (floor), and tilted it upwards at a maximum permissible angle of 5 degrees.
To protect the lower rear wing from high temperatures, Renault’s carbon fiber was covered with thermal protection to prevent it from melting.
While the driver is on throttle, hot and fast exhaust gases lower the pressure on the lower side of the rear wing and increase the downforce. Though it is not a big improvement it will come useful when the car is accelerating.
Last season the teams used exhaust flow to blow them below or directly on a 20 cm wide wing on the rear security structure (monkey seat).
But this season this wing is forbidden even though the current 750 mm high T-wing at the lower position (ahead of the exhaust pipe end) is still allowed.
It will be interesting to see if other teams will copy Renault’s solution.