McLaren will introduce its version of Red Bull's blown rear end concept for the British Grand Prix at Silverstone.
The system channels air from a low exhaust via the diffuser to improve downforce, and as well as being part of Red Bull's design, it will also appear on the Ferraris from this weekend's European Grand Prix.
The team's engineering director, Paddy Lowe, said that the system was now nearly ready to fit to the McLaren, and would be evaluated at a straight-line test before being used at Silverstone.
"I think all the rest of the teams, it's pretty much common knowledge, are playing catch-up in that area," said Lowe. "It's quite a significant performance step. That's something we're aiming to bring to the British Grand Prix and to try and make it work from the outset.
"There are some technical challenges with it, especially blasting your bodywork directly with exhaust flow can generate some particularly high temperatures. It's not without challenges to hit the ground running with a system like that when we don't have any proper track testing. We'll be doing trials at an aerodynamic day before Silverstone to hopefully have it working in the practice sessions and race."
He admitted that it was frustrating that Ferrari had been able to get its system on track first, but said it was not guaranteed to vault the Italian squad to the front this weekend.
"I think we'll have to see how they get on with it," said Lowe. "It's a shame that some others have been slightly quicker than we were getting it, but we are where we are.
"It all depends at each circuit on how the different characteristics suit some cars and not others. For instance, Ferrari really struggled in Turkey. I can't predict where they'll end up any more really than I can predict where we'll end up."
Lowe added that the system had required substantial changes to McLaren's design, and that getting it to work without having an impact on reliability would be a challenge.
"It has been a pretty massive project, not least because you've got a new exhaust system and that has many challenges – especially when you try to do it quickly," he said. "In terms of how we see the risk profile going into its first race, we're reasonably confident that we will get the performance we predict. We've tested in the wind tunnel, we're able to evaluate in the simulator how these things work.
"So, I think we're very well prepared to exploit it. The concern will be more about making sure it's reliable and fit for racing."