PARIS, France - Lotus Formula 1 driver Romain Grosjean wasn't always his smiling self during pre-season testing in Bahrain at the end of February 2014.Video has emerged of the Frenchman angrily thumping the tool benches in the Lotus garage as he apparently discussed the new Renault-powered E22's obvious problems with an engineer.LOSING HIS COOLThe team sat out the first test days at Jerez, Spain, because of financial problems so the extent of Lotus' situation with its troubled 2014 car became clear only in Bahrain."Of course," Grosjean was quoted as saying by Speed Week, "we are still far away from a good performance. We need to understand the brake-by-wire system, the new power unit and charging the batteries."In these areas it doesn't look so good but together with Renault, we will work in the next two weeks until Melbourne to improve."Asked how he would keep his ever-present smile, Grosjean answered: "Think of my son."Watch the temper tantrum:Stay with Wheels24 for the 2014 F1 season – fresh reports every day.