London, England - McLaren's technical experts are confident they can claw back much of the aerodynamic performance taken away by rule changes enforced by Formula 1's governing body in 2012.The 2012 regulations have forced teams to re-position exhaust systems so that they exit periscope-style rather than having the gases blown through the rear diffuser for aerodynamic gain.Sophisticated engine mapping systems that allow a constant flow of hot exhaust gases even when the driver is off the throttle have also been banned.Technical director Paddy Lowe said: "We now have new constraints in terms of the geometry, so that is where we can put the exhaust pipe and what angle it can be directed at, all of that intended to keep it high and away from the diffuser. "The fact of the matter, though, is that exhausts exist on a car, you have to have them, they blow gas. That will always generate some performance, a finite level of performance. Even just simply blowing exhaust out of the back of the car produces thrust that makes the car quicker," he added.Lowe said: "So there still is a very narrow extent to which you can use exhaust gas to generate performance aerodynamically. Much, much reduced from last year but inevitably we've been trying to look at the ways to make the most of that."The MP4-27 showed off in a functional launch with the minimum of fanfare drew attention for the tightly-packaged rear-end and smooth bulges on the bodywork where the exhausts exit.AMBITIOUS TARGETSEngineering director Tim Goss said the focus now was more on extracting gains from 'unblown' performance at the rear of the car rather than 'blown'.He was coy when asked to put a figure on the overall loss of downforce compared to 2011, when McLaren won six races and finished overall runners-up to Red Bull and Sebastian Vettel in both championships.Goss said: "We've set ourselves some ambitious targets and we'd expect to recover a lot of what we lost. You optimise around a certain package and we thought we were particularly good at achieving performance from the exhaust system and blowing the diffuser last year."You pay a price in terms of base performance of the car, we knew that, there were prices and trades that we were accepting, and ultimately last year it produced the quickest car," continued Goss."This year we've taken those gains back and worked harder on them and pushed that area harder. I don't want to quote numbers, but we've set very ambitious targets and we'd like to think that we go back with an equally competitive car," he said.