Haas F1's troubled build up to its Formula 1 debut has hit another hurdle as Romain Grosjean suffered two offs and another stoppage on the penultimate day of testing around the Circuit de Catalunya.

Following a positive first week with the new VF-16 last week, Haas has endured a series of technical issues in the second test, with a turbo issue all but eliminating it from track action on Tuesday and Wednesday.

With Grosjean returning to the car for the final two days, he enjoyed a more productive day than his team-mate Esteban Gutierrez by completing 77 laps. However, it was interspersed with an off at turn four before lunch and then again at turn one after lunch. A final stop with minutes of the session remaining brought out a third red flag.

Related Articles

Issues traced to a brake-by-wire problem that is leaving Grosjean lacking some confidence, he admits his optimism has been harmed by his tough day.

"I wasn't 100 percent confident when I got back on track and had to brake for Turn 1. I probably braked 20 metres earlier than I should, but it's part of the life. We knew we would have problems. I did not expect to spin at 300 but it happens sometimes.

"I think it will be solved for Melbourne. Hopefully overnight we can do a big update. We have really seen today what's the problem and for the first time we know where it comes from, so hopefully for tomorrow we have some fix. That will help us a lot."

Despite the set-backs, team principal says the problems simply allow Haas to learn and develop this way.

"We try to get better tomorrow, we will keep on developing for sure. I wouldn't say there are concerns, this is what happens when you develop what you. I you don't push the car you won't know how it goes and we need to find this stuff out as much as possible before we go to Australia."