Struggling McLaren-Honda expect a significant step forward in performance at the next grand prix.
The team, who have yet to score a point this season, are introducing developments to both car and engine in time for the Spanish Grand Prix on 10 May.
Racing director Eric Boullier said: "Most of the back end of the car will be new.
"Every race we bring new chassis parts to increase performance."
He added: "Hopefully we will have some new engine technology which will allow us to unlock some performance."
Sunday's Bahrain Grand Prix was McLaren's most competitive of the season so far, with Spaniard Fernando Alonso just missing out on a point in 11th place.
Although the team had a terrible weekend with reliability on team-mate Jenson Button's car, which ended with the 2009 world champion failing to start the race, Alonso's performance confirmed an upward trend since the start of the season.
However, the Honda engine, which is new to Formula 1 this year, is still significantly down on power compared to all its rivals.
Alonso said before the race in Bahrain that he expected it to be the last grand prix at which McLaren were not able to fight for points, but he cautioned against setting hopes too high for McLaren's performance at the first European race of the season.
"We cannot put all the expectations in Barcelona. People will think we will win the race and this is not true," the two-time champion said.
"We can talk about Barcelona, but with feet on the ground.
"In Barcelona we should see a good step and from that moment we can start enjoying races and doing a normal development phase. This year we started very low but we hope to finish very high.
"Hopefully in Barcelona we can enjoy the race a bit more, but when we will fight with the top guys is more long term."
Boullier added: "Any step would be satisfying. We cannot expect to have a huge step. These days are past. It is very incremental and this is modern F1.
"In terms of chassis, over the next four races there will be some massive upgrades coming, much bigger than what we have brought to the last two races. But I will be more satisfied when we are fighting for pole."
Both Alonso and Button are also optimistic that McLaren can put in a stronger performance again at the following race in Monaco, where engine power is a less significant part of the car's overall performance because of the twisty nature of the street track.
Alonso said: "We are all committed to this comeback. It is easy to panic in these tough moments but the reality is the opposite - we have huge motivation in everybody and hopefully we can use [that] in a good manner.
"In Barcelona we will see the first step and at Monaco the power effect is low so we could have a good race there. So the next two or three races are going to be interesting for us."