the carbon brake disc becomes smooth as glass, reducing friction between the pads and the disk, hence lessening braking power. To combat this, in 2006 Juan Pablo Montoya adopted discs with radial grooves that increased the bite rate between disk and pads, increasing the average temperature of the brakes. Conversely, cooling the cars' engines is a major concern. Formula One cars do not incorporate any form of forced cooling, relying solely on air moving over the car to remove heat from the radiator elements. In the past many teams used to adjust the radiator intakes to allow for extra airflow, creating the once-common "Monaco nose". Before 2014, teams also used closer ratio gears, as there are hardly any long straights in Monaco and acceleration is at a premium (starting from the 2014 season, the same gear ratios must be used throughout the season). A special steering rack with a larger pinion gear is also fitted to allow the cars to be driven around the tightest corners. In other motorsport FIA World Rally Championship The circuit has been used as a special stage during the WRC Monte Carlo Rally, for example in 2008. FIA Formula E Championship On 18 September 2014 it was announced the Formula E would be racing on a shorter version of the Monaco Grand Prix circuit, which was subsequently used for the 2014–15, 2016–17 and 2018–19 seasons. This layout omitted the regular section of the track between the climb up the hill at Beau Rivage and the Nouvelle Chicane at the exit of the tunnel, instead turning right immediately after Saint Devote to head downhill, before rejoining the regular layout by way of a 180 degree turn at the chicane. Monaco was not scheduled to be on the calendar for the second season of Formula E because it took the slot on the calendar filled by the Historic Grand Prix at Monaco every other year. The inaugural Paris ePrix took its spot on the calendar for season two, with the Monaco ePrix reinstated for season three. This biennial agreement will continue at least into Formula E's fifth season. A new track layout was used only for the 2021 Monaco ePrix: the layout is similar to the Formula One layout, with only slight differences at turns 1 (Sainte Devote) and 11 (Nouvelle Chicane). This new layout has a length of ; the distance of the track being increased