2011 vs 2012 Exhaust Systems
In 2011, Red Bull Racing pioneered the off throttle blown diffuser concept. This innovative system helped the RB7 generate a lot of downforce which made it the fastest in the hairpin sections of all tracks throughout the year. Although the RB7 was down on power (it had the Renault engine) compared to the Mercedes and the Ferrari engine powered cars, it made up for that loss by being very quick and having much more traction through corners compared to its rivals. The team relied so much on the RB8’s superior performance through corners that it even set shorter gear ratios for Sebastian Vettel car setup in Monza (which is mostly comprised of long straights) last year. Shorter gear ratios would provide much more traction as compared to the longer ones but it could have made Sebastian vulnerable on the straights (specially against the DRS) – so it was very important for him to maintain the lead and build distance so that cars behind him would have no chance to apply their DRS. This was one of the main reasons why Sebastian tried the brave move around the outside of Fernando Alonso’s Ferrari to regain the lead. The Ferrari would not have been able to run away from Vettel’s Red Bull so Vettel would be vulnerable to the DRS of Webber and the two McLarens behind him.
So, first let us understand what was the 2011 exhaust system on the Red Bull. When the driver presses the throttle, the hot exhaust gases are channelled towards the car’s rear diffuser, and that increases the airflow through the diffuser. This very fast-flowing air blocks any other air from coming into the diffuser from the sides, thus increasing the downforce. This is what is called the “blown diffuser” concept. Red Bull found out a way to blow the exhaust gases through the diffuser when the driver is ‘off-throttle’ too. To do this, they developed their engine mapping so that the diffuser can be blown even when the ignition and the fuel supply are cut off. Mercedes went even further in this direction. They found out a way, with their engine mapping, to blow the diffuser during off-throttle but with fuel still being supplied although there was no ignition. This phenomenon is “hot blowing” (hot airflow) while Red Bull’s was “cold blowing” (cold airflow).
The FIA has banned exotic engine maps and the off throttle blown diffuser concept for the 2012 season. They made a similar ban on these concepts during the British Grand Prix last year which saw Red Bull and McLaren suffer the most among the frontrunners and Ferrari took advantage of the situation as their car was having problems in generating enough downforce because they couldn’t get the off-throttle blown diffuser to work properly.
Formula 1 history tells us that whenever the FIA have banned innovative ideas, the engineers have found out new ones to try and extract similar performance which they were able to achieve with those banned ideas. The 2012 season is no different to that. Adrian Newey has tried out four different solutions of exhausts since the first preseason test in Jerez on the RB8 and Ferrari are also said to be trying to make their innovative solution work, but till now both teams have not been successful to extract full performance from their cars, so it is no surprise that neither of them has the fastest car out on the track.
One of the main themes of this years’ exhaust solutions has been exploiting the Coanda Effect. The Coanda effect states that when air flows past a surface, sometimes it develops the tendency to get attracted towards the surface. This year’s regulations state that the exhaust outlets have to be much further forward on the car and they have to point atleast 10 degrees upwards rather than towards the diffuser. The bodywork around the exhaust outlets has been designed in such a way that the gases follow the bodywork and bend downwards towards the diffuser. The diffuser is around 20 degrees pointing downwards, so the teams are being able to bend the airflow by around 30 degrees!! We can say that this has been an awesome innovation and more work is to be carried out in this direction so that by the end of the year, the teams can recover most of the downforce lost by the banning of the off-throttle exhaust blown diffusers.