There’s certainly been a lot of talk about the final races and the upgrades that teams are bringing for the last push to season’s end. Amongst those upgrades, the exhaust systems are starting to take the spotlight. Exhaust systems have been adjusted, improved and upgraded all season long but an interesting story this week from AUTOSPORT has Lotus F1 bringing an all-new exhaust to take advantage of the Coanda Effect. Ferrari, McLaren and Sauber have been using the system this year and lotus F1, while delayed in deploying their dual DRS (DDRS)  system, have pinned a lot of wind tunnel time and hope on the new exhaust coming in Korea.

The Coanda Effect is an aerodynamic term that is achieved when the exhaust is down-flowing and provides the desired downforce efeect teh chassis needs to stay planted on the track for better performance. For you veterans out there, you’ll be very familiar with the term but for new fans of Formula One and its distinct aerodynamic war, I found a very humble video that does a great job of explaining how the Coanda Effect happens in a very simplistic way. Instead of me just blathering on about it, I thought I would help you find a video and show you what it is. Check it out:

When the publisher of the video using the straw to create a stream of air, you can really start to understand how this effect will help glue the chassis to the tarmac using the exhaust. Last year, Red Bull enjoyed a competitive advantage from the blown diffuser exhaust system and the technical genius, Adrian Newey, has admitted that this year’s ban on the blow diffuser has really stymied their ability to be as competitive as they would like. The Coanda Effect is something Lotus F1 is hoping will bring the types of performance gains they need to finally win a race in 2012. Will they forget their efforts on the DDRS system in favor of Coanda?  Some suggest they will but if their DDRS system is completely passive, then it may comply with the 2013 regulations and thus be worth continued development.

Lotus technical director James Allison said:

“We’ve been ploughing something of a lonely furrow on the circuit with our relatively straightforward, power-maximizing exhaust,” he said.

“However, since well before the launch of the E20 and to the present day we’ve been carrying out parallel developments in our wind tunnel programme based around a Coanda effect exhaust.

“Once we saw the potential gain of the Coanda system surpasses that of our current design it was clear that we needed to implement it, both for the benefit we could get in the last quarter of this season and also for learning experience it presents us for next year.

“We will run our first version of this style of exhaust in Korea.”

We’ll see if it makes a bog gain in performance and I will be intrigued to see how many teams adopt this exhaust should Lotus F1 prove to be substantially quicker this weekend.

An F1 fan since 1972, NC has spent over 25 years in the technology industry focusing on technology integration, AV systems integration, digital media strategies, technology planning, consulting, speaking, presenting, sales, content strategy, marketing and brand building.
  • Rapierman

    I’d also be interested in finding out how fast the FIA bans it.

    • mini696

      …and ho they manage to ord the ban.

      • mini696

        Damn old keyboard.


  • What’s shown on the video is rather dominated by surface tension as opposed to Coanda effect.
    I have a blog article explaining what it is –

    Lotus went specifically for aero-neutral exhaust, which is good for the tires, but not good for the cornering downforce on aero tracks, like Silverstone for example. So, it’s a logical move to recover the lost rear downforce due to diffuser regulation changes.

    • Dan

      He also shows it using air from the straw which is the most pertinent bit and the same effect is shown, the effect is more dramatic when shown with water due to surface tension but for demonstrative purposes the water method is very useful.

      • Schmorbraten

        No, the part with the air from the straw is just the Bernoulli effect – if a gas moves quicker, the pressure drops, which pulls the spoon towards the air flow. The water stream attaches tightly to the spoon because of surface adhesion. At the point where the water leaves the spoon it spills off to the left, still mainly because of surface adhesion. But the coanda effect describes a similar phenomenon with gas flows, that they tend to follow a curved surface – a bit like the water which leaves the spoon to the left.

  • NeilM

    Nicely done video. However it is not “simplistic,” a word which does not mean what this article’s author thinks.

    • Sorry if I missed the appropriate word. I was thinking this video shows an element in a way that may be easier to understand. Perhaps I should have use the word “simply” instead of simplistic. Hopefully you’ll forgive my being a simpleton on this. :)

  • JasonI

    Can you take this down now before my competitors see it?

  • It could get banned for the throttle but it sure does not affect performance. Just hope the riders do not overuse the noise especially on the streets.