Lotus go Coanda

In Korea, Lotus became the latest team to migrate to a Coanda-type exhaust system.

In Friday’s practice sessions, Lotus ran the system, generally assumed to be advantageous for gaining downforce. Later, speaking in the FIA Friday press conference, technical director James Allison stated the likelihood was that his team would retain the system and run it during the rest of the weekend. “We’re reasonably happy with the way they’re working,” he said. “I think we’re at the beginning of a relatively long road with them – they’re not straightforward to make work perfectly first go out but the numbers we’re getting from them are good.”

Lotus have ran with a more straightforward system for much of the season but Allison revealed work on the Coanda has been continuing in parallel at Enstone. “We kept working on the [coanda] because it was fairly clear that was where the centre of gravity of opinion in the pit lane was and also because it was a reasonably productive avenue back in the wind tunnel. It got to a point where the gain of the coanda system was sufficiently far ahead of our previous race system that it was quite clearly something that we ought to look at both for this year and also to make sure we’re doing the right thing for next year. That’s pretty much the history of it; probably could have committed a bit earlier but then things were going quite well for us on the track as well.”

The decision to go with a conventional system from the start of season was characterised by Allison as being based upon the trade-offs between potential gain and risk. “At the point when we were committing to what we were going to start the season with, we had two paths: a coanda path and what we chose which was a very simple exhaust which was there to optimise power. At the time, the coanda solution was worth a little bit more theoretically than the power maximising solution but you had to be confident that it was going to deliver all the downforce that it promised, because you could be fairly certain that it was going to deliver all the horsepower loss that the more convoluted exhaust pipe requires. So if the downforce didn’t materialise, you knew you were down on the deal. Where we were when we launched our car, that was a relatively finely balanced decision. We launched with the simple thing.”