What difference will off throttle diffuser ban make?
Red Bull Racing
Posted By: James Allen  |  19 Jun 2011   |  9:19 am GMT  |  190 comments

The FIA Technical Working Group met at the end of the week to rubber stamp the FIA’s ban of off-throttle blown diffusers. They also discussed how the ban can be policed. They also accepted that from next season the whole concept of blown diffusers goes out of the window.

From Silverstone this year onwards engine makers will be limited to using just 10% of engine over-run when the driver is off the accelerator.

This will kill of the current practice of blowing high pressure exhaust gas through the diffuser when the driver lifts off the throttle – ie in corners – creating downforce but at the cost of 15% increased fuel consumption.

The key question is, will this change the order at the front in F1?

At a rather gloomy post-race press briefing in a rainy Montreal paddock we sat with Ferrari team principal Stefano Domenicali who posed this question himself,

“We need to see in Silverstone, what is the real effect of this change in the regulations with regard to the effect of the exhaust,” he said. “Then, we will see really where is the second championship in terms of the level of performance above all in higher downforce tracks.”

This is probably wishful thinking for Ferrari, whose lead driver Fernando Alonso, lies fifth in the championship almost 100 points behind Red Bull’s Sebastian Vettel.

Off throttle blowing is a technology that was pioneered and perfected by Renault for Red Bull Racing and from early last season was part of the reason why they step up in performance in the final part of qualifying and whenever they need the extra performance.

Of course most top teams have copied the technology. McLaren and Mercedes were active in this field at Singapore last year, as we discussed it there with McLaren’s Jonathan Neale. So all the teams will lose something.

But Red Bull have the best system and so will lose more of their performance advantage. But how much, is the key question?

Engineers I have spoken to suggest that the real differentiator for Red Bull in qualifying is its very powerful DRS rear wing, which can be used on qualifying laps in corners where other teams simply cannot use it, as the car would become unstable.

Of course, the superior blown diffuser created some of the downforce and stability which allowed them to use the DRS in this way, but to be clear, it’s not likely that with this cut to 10% of its current level they will suddenly lose their ability to exploit the DRS.

Red Bull has owned Silverstone in the last two seasons and is likely to still enjoy a performance advantage in qualifying thanks to the DRS, but we’ve seen them under pressure in race conditions in the last four races. not least with the dodgy KERS, compared to the strong units on the Mercedes and Ferrari powered cars.

It looks like the chasing pack of McLaren and Ferrari are closing on them and the race at Silverstone could well be very tight, maybe even tipping the balance away from Red Bull in races. But I still expect them to be quick in qualifying.

Featured News
MORE FROM Red Bull Racing
Share This:
Posted by:

Add comment

E-mail is already registered on the site. Please use the Login form or enter another.

You entered an incorrect username or password

Sorry that something went wrong, repeat again!

Thanks for the article. I have always observed that a lot of people are desirous to lose weight because they wish to look slim and attractive. Having said that, they do not always realize that there are more benefits so that you can losing weight also. Doctors assert that fat people experience a variety of diseases that can be directly attributed to their own excess weight. The good thing is that people that are overweight as well as suffering from diverse diseases are able to reduce the severity of their illnesses by means of losing weight. It is possible to see a constant but identifiable improvement in health as soon as even a small amount of fat reduction is realized.


If teams can’t change ECU settings between qualifying and the race, will drivers still be able to change engine settings via the steering wheel controls – for fuel saving etc?


ok Guys, The Redbull is faster than Mclaren in qualifying but not on race pace.

NOW! The creative engine map fiddling from quali to race sim will be illegal from Valencia onwards, in which case the Redbulls will pretty much use their race mapping for qulifying aswell

So, am I right in saying since the Mclarens have the faster car in race mode, they will also be faster in qualifying, since there will be an eradication of ‘creative’ qualifying only engine mapping?


…[mod] rbr will take the driver’s and constructor’s championship this year and that’s definite


Changing interpretation mid-season is soooo wrong when ….

1. Teams have spent (and were spending) millions to copy and catch-up

2. All the cars passed scrutineering multiple times

3. There is no safety issue

Surely any innovation or “exploitation” should be (firstly) applauded and then (secondly) assessed by FIA to see if it will be allowed to be used NEXT season. Such a decision should be made at, say, Race 4 (?) and then announced so that all teams can decide if they want to pursue (or continue to pursue) the same method/idea or disregard it totally and battle thru the season “as is”. Only exception should be when safety is compromised when something would be “bannable” immediately.

What’s next? Changing the interpretatiosn race by race ? Weight penalties perhaps ?


I believe the clarification in the rules is being brought about by the possibility of a challenge by the teams who are not using the Exhaust Blown Diffuser (EBD). HRT were threatening a challenge a couple of races ago, but promptly withdrew that threat. I can only imagine that HRT was somehow persuaded to table their challenge with a promise to address the EBD issue in short order.

The challenge would have been on the throttle body being used as a moveable aerodynamic device on overrun which would contravene the rules about moveable aerodynamic devices.

If I am not mistaken, a successful challenge could have ended up with a loss of constructor’s points for all teams found to be running the EBD, and the powerhouse teams in F1 certainly wouldn’t want to see that since points = money in F1.


Thanks for the info, wasn’t aware of that side of the story/issue. One wonders if it was HRT acting alone in rogue attempt to steal the titles (!)or if they were being “actively encouraged” by other interested parties. Methinks the latter !


A recent autosport article suggested that (very ) high noses could be banned because they make ‘take-offs’ (such as Webber at Valencia last year) more probably in rear-end accidents.

With Heidfelds crash last weekend, and also Kobayashi at Melbourne last year, it seems there is an additional danger from front wings jamming underneath the front wheels and leaving the drivers without braking or steering.

I wonder if it’s time to ban the high nose?


I think it will make a massive difference as Red Bull won’t be able to use the DRS in the corners due to the loss in downforce. They may still have an advantage in qualifying on most circuits, but this advantage will almost certainly be cut by at least half a second. In the races, I think McLaren are going to have the advantage and I expect Lewis to be winning the majority of races from Britain onwards. I think he will win in Valencia.

Off the topic, there has been talk about Hamilton’s aggressive driving style. Can you do a segment on driving styles, comparing Hamilton to Alonso to Button to Schumacher to Vettel, as well as comparing other drivers, both past, present and possibly the future, including Senna and Prost, please?


As soon as brake is applied, the DRS sytem is switched off. So the off-throttle blown exhaust does not work in combination with DRS.

After this ban, everyone will be less grip going into the corner or wherever brakes are applied but it applies for everyone.

Since RedBull is the most experienced in this tech. They are likely to loose the most. I guess how fast each team adapt to this is the key to wining.


Rules will always be broken when there’s innovation. Just don’t get caught. FIA will shoot themselves everytime they change the rules which seems like a yearly affair currently.

All you need is a Newey to throw things out of the box and the head scratching begins and last quite awhile.

Silverstone should be interesting and will we see a change in pace from Red Bull? I hope so. Will RB be slower and the others even slower.


Two things:

On the BBC possibly getting rid of F1, it seems daft considering they only got it in 2009. Doing it from a studio like ITV used would surely save a bit of money as that’s the big issue. As long as folk like Martin and Ted are there though then channel-hopping could be worse.

With Button to Ferrari, would he himself consider it? At either team, he is/would be considered the number two, and even more so at Ferrari with Alonso. Being able to say you drove for McLaren and Ferrari is a big honour, but if I were Jenson, I’d stay at McLaren where I have a betetr chance of competing with my team-mate.


I’d stay at McLaren too, but you can understand the lure of Ferrari if given the chance.

I think he’s better at McLaren, and he’s done really well.


I may have misunderstood the technical explanation – the probability is that I did – but does this mean that the cars will not now have to carry so much fuel? If so, what are the implications?


Yes, those cars that had the off-throttle EBD will now be able to carry less fuel. It will be a marginal gain that will partially offset the loss of downforce on corner entry.


James said:

Engineers I have spoken to suggest that the real differentiator for Red Bull in qualifying is its very powerful DRS rear wing, which can be used on qualifying laps in corners where other teams simply cannot use it, as the car would become unstable.

James – Red Bull can only exploit DRS this way because the off throttle gives them extra downforce and stability through corners.

I bet they will really lost some performance advantage because their system is very interactive with DRS.

What makes me wonder is how Newey discover that. The man is really a genius.

Anyway, theres a great article in Auto Motor und Sport suggesting that Red Bull can’t use the off throttle system in the entire races because they would have to add more 15 kg of fuel in their tanks to feed the system.

According to AMuS, FIA is trying to ban those agressive engine maps already in Valencia.


Sorry, but you are wrong.

They can exploit their DRS wing because of how they have designed it. The main-element is still very effective when the flap is raised, whereas on some of the other competitors, their wings cease to function effectively when DRS is open. Their advantage there is wing design.

Their system does not interact with DRS. While the EBD does give a more rearward downforce bias, potentially offsetting the loss of downforce of the DRS, the EBD affects much more than merely the back end of the car. The EBD helps the entire floor generate more downforce, so I doubt you will see much of a difference when they are not able to use the EBD off-throttle.

The big difference is wing design. Red Bull have managed to drop the drag while retaining significant downforce when DRS is open, and that is their main advantage in qualifying.


Thanks for your explanation, Malcolm!


I doubt it’s that simple. The rear wing is one of the most visible components of the car. Even here on this forum there’s a lot of people who have a faily good idea of the design of the Red Bull DRS rear wing. So how come no other team has copied it? There must be something else stoping them from using that design / set-up. Time will tell if that is indeed the EBD aided by the special engine maps that have now been banned!


RBR was running away with championship so FIA manipulated the regulations to give other teams a chance, to boost ratings.

Pathetic, 2011 season is a joke, together with DRS and quality lowered tyres for entertainment purposes…now this. How about demand RBR drive around with 3 wheels?

If another team wins thos season it will be a joke because FIA helped them manipulate the regulations while they had no RIGHT. What RBR is doing is not illegal, but clever.


With the “hot-blown” exhaust banned the only real change to the competative order I see coming will be that Mercedes and Renault might fall back into the clutches of Sauber, Toro Rosso and Williams, all of whom dont use the system (not sure whether Force India have it or not), but its worth mentioning that its only really effective in slow corners and there arent too many of them at Silverstone.

As for Red Bull’s DRS wing use in qualy, they really have the advantage there in fast corners, somewhere the hot-blown exhaust system doesnt get much use and so doesnt effect the car much.


Going off topic James, what do you make of the story in todays News of the World by Ian Gordon that Ferrari are intrested in signing Jenson Button for next season?

Andrew Benson is on his BBC blog is also reporting the same story and reporting Jensons 3 year deal with McLaren has a opt out clause for 2012.


I bet Ferrari would love to get Button, but it looks like Hamilton might leave at the end of the season, which would enable Button to ask for more money in order to stay and establish himself as the No1 driver in the team.

He went to McLaren to prove he can compete with Hamilton, which he has done, so I think now he is eyeing another championship and a good start would be to become No1 at McLaren.


If you look back at my reporting from my trip to Maranello three weeks ago, you’ll see that I suggested that if I were Stefano Domenicali, I would sign Button alongside Alonso. He’d get along fine, would score lots of points, is very strong technically, doesn’t mind being beaten by a team mate on pace and generally gets the job done. It doesn’t surprise me at all that Stefano is looking at him.


Button does seem to be keeping his options open at the moment in regards to a new contract, but I think he’s actually got his eye on Webbers seat at RB. The only question would be would Vettel be happy to have such a quick driver alongside him.

Edward Valentine

I’s a good shout and an interesting thought and a Brit as good as JB would do nicely in terms of RedBull PR. Of the three options which would you say is the best? For the passion and history I’d say Ferrari but for a best chance at the title it must be RedBull.

It would also leave an open seat for Di Resta at McLaren.


It was said some years ago that Jenson is a perfect ferrari driver (i.e exactly the type of driver to go there and do well).

I am a McLaren fan through and through, particularly since Jenson arrived. But I’d love to see him win races at Ferrari.

I dont think Jenson will move. He’s got the team right behind him at McLaren. He is very very popular there by all accounts, and if anything why would he go from McLaren where he appears to get absolutely equal treatment, to Ferrari where you can guarantee he wouldnt.


Would be good to see Button in red, however one thing is (let me know if you dont agree) would he be able to adapt to the Ferrari culture. Button has been with British teams all his career(same I think applies to the Webber rumours). Being towards the end of his F1 driver career would the lifestyle suit him? Or is Ferrari now very different?


Wow, I’d missed reading about this. I’m a McLaren fan and would hate to lose Button, but I can see why he’d be attractive to Ferrari.


Yeah but Button doesnt share the same philosophy with Ferrari when it comes to second driver. “Jenson, Alonso is faster than you” So dont worry, it aint gonna happen.


Might be a smart move for Ferrari it would be suicidal for Button unless he wants to become the new Rubens.


And if you were Jenson?

Already at ease and respected in a team with an improving car and a team mate who seems rattled and erratic?

More importantly, he himself said that he threw that car around last weekend like he doesn’t usually – and it paid dividends. If he learns from that and finds the line Lewis finds so hard to tread surely next year is his best chance of a crack at a 2nd title – but only by staying at McLaren surely?


Button I don’t think can beat Hamilton or Alonso on pace.

Button is consistant and so when it rains and everyone going mad and makes mistake MR consistant comes through, but when its pace vs pace Button gets owned.

Only Hamiltons mistakes at the end of last year kept the two so close. Given that Hamilton has a tendency to muck up (see 07, 08, 09 and 2010, in particular when he had a WDC capable car) and Alonso doesn’t (see the later half of last year) then Button doesn’t stand so much of a chance.

Added to that Button is very British and fits in with McLaren in its mentality. Ferrari is emotional and works very well with the hot spaniard. Alonso didn’t work well with McLaren. Massa who cries and dances and has good days and bad works well with Ferrari. They love him despite his recent results. Kimi never fitted in with Ferrari and lost interest after 1 and a half years.

Button and McLaren go together like some Forrest Gump analogy

Edward Valentine

When Kimi went from McLaren to Ferrari it was reported in the media as early as August 2006 which was well before the season end, so we may indded hear something soon. I’d love to see JB drive for Ferrari. Sarebbe molto bello per tutti di noi tifosi!


What would you say the chances of it happening are James? I’d say he’s looking increasingly settled at McLaren, but then Ferrari is Ferrari.

Given that he hasn’t been massively behind Hamilton I’d actually rate his chances against Alonso, certainly on a one lap basis.


The best team mate ever…and damn fast he is…JB to Ferrari…is my love for red showing through …not sorry at all 🙂


I will look at the article and thanks for the reply James.


It’s my guess that the FIA will police the ban by having a template engine map on a plug in analysing computer which would make it very easy to check what the engines ignition system would be doing off throttle. The ignition system has to be sufficiently retarded so torque is negated currently otherwise the cars would be off the track.


I’d argue that Red Bull’s DRS advantage in qualifying is a symptom of its superior downforce and not an advantage all by itself. Redd Bull has more downforce from the rest of its components which is what gives them the ability to remove rear wing at more places on the track than anybody else. The big question is how much of this ‘DRS on’ downforce is due to the blown diffuser they run? This is why I’d say its all still very much up in the air.


The rule change will be exploited by somehow having the driver Stay on the throttle while cornering but at cornering revs.

The blown gases get limited 10% ONLY WHILE OFF THROTTLE. So anyone who can somehow get the driver to saty on the throttle while cornering and still blowing the gases will not be doing anything illegal. Stay on Throttle while cornering but at cornering Revs.


To produce the gasses on the overrun the ignition has to be retarded — by 30 degrees or more. It’s not that difficult to police a ban on retarded ignition off throttle (ie on the overrun). If the ignition is not retarded and the driver has the throttle open he’s producing power at the wheels causing a spin in the corner.


It is surely common practice in rallying and some other formulae to keep one’s foot hard on the gas whilst braking into a corner


james, with regards to the banning of the blown diffuser mid season, the fia have said they feel this to be illegal and stated their reasons of “movable parts being used to influence aerodynamics/downforce”. Now surely a team such has sauber who don’t run the system and were DQ’d at start of the season (losing several valuable championship points) for a rear wing infringment would have a case for it being overturned? How can they allow the richer teams to take more of the points with use of an illegal system with no punishment yet punish a smaller team for a simple wing measurment error?


James, is it true that Pirelli have said that Red Bull’s exhaust is too close to the rear tyres for safety reasons? If so, is there any benefit for Red Bull from this (either in qualifying, at race start / restart or in the race)and could this be the next thing to go if it is indeed true and indeed dangerous?


Looking and what is happening today…I simply can’t believe that a single man (A.Newey) is worth more that the army of highly rated engineers from other team. How is that possible that noone can get close and they all look at him with open mouths…not even believing that they can beat him.


Because he’s been in the sport so long. Not many ideas are actually brand new in F1. What Adrian is good at doing is having an encyclopedic knowledge of past technologies that have been tried and knowing when technical regulation changes will allow one of them to be used.

I think its great that theres a new team at the front of the pack upsetting the old order, although as a spectator I’d prefer the gap to be a bit smaller.


It isn’t just Newey, RBR hand picked a large number of top engineers from every other team when they were on the way up. (Don’t get me wrong Newey is a genius, no doubt, but one man does not make an entire team).

Hence when the latest RRA was discussed one team did not want any change to the repercussions for over spending. JA has there been any developments since the aforementioned rumour?


He is actually a space alien in disguise, with advanced knowledge we can only guess at.


Exactly when do you guys think that off throttle blowing is used?

Braking and a few seconds of coasting after braking in a few turns. This is no more than 20% of a lap on average.

Scarbs states that RB is does not have the most aggressive off throttle mapping. Do any of you have a better source?

Rb is going to be fine.



As qualifying is seen as an all out dash for position I expect the DRS was seen as yet another device that could improve pace over one lap for everybody. Of course those with the most aerodynamically efficient cars are likely to gain the most. – And let’s not forget F1 is also a development race rather than just a numbers of guys simply competing.


You’ve made the comment a few times that the power of the RBR DRS is a major part of their advantage.

I’m not entirely sure what you mean by this; is it that the DRS is more effective at reducing drag/ achieving higher speeds (which seems unlikely given the similar parameters within which all teams operate, though potentially differing upper flaps) or is it that their overall better downforce, partly through the EBD allows them to utilise this system earlier (we saw this in Spain mid-corner at the last).

If its the former, it is a fundamental difference as you suggest, if the latter, more a consequence of the overall difference in package and not really due to DRS.


I guarantee you that when all those engineers left the meeting, *each one was thinking “ok, here’s how we get around that!”


+1 from me to all those who have wondered why the DRS is allowed during qualifying. I have never understood why an aid to overtaking is either allowed or is appropriate to be used during qualifying. The more so in that it has limted defined uses during a race.

That said I am not a fan of qualifying anyway. The concept of a system designed to rank the cars in order of quickest to slowest so that the quick ones can clear off and reduce close racing has no merit for me.

I would prefer the start order to be based on the pre-race WDC order: maybe 5,4,3,2,1, then 10,9,8,7,6. The remaining cars to decide their stating grid positions by means of a race on Saturday in place of the present qualifying. This will allow the slower cars more development / testing time, and hopefully bring the performances closer together.

Now I would watch that instead of the individual cars setting a lap. I cannot get excited with the news that car “x” is faster than car “y” by 0.001 seconds. However a qualifying race for the back markers? Bring it on for me.

James. Who are “they” who thought that unfetterd use of DRS in during the qualy hour was a supposedly good idea? The names of a few of a “suspects” would be appreciated.


The FIA had to give free use of the DRS device in qualifying to avoid certain situations that could ruin the spectacle of the races. For example, there were concerns that if DRS was not in use in qualifying, some teams would opt not to use it at all, race included. Any team opting not to use the DRS device would be able to optimise gear ratios to achieve best top speed under normal conditions i.e. without the use of DRS. Any car that was optimised for top speed whilst using DRS could be significantly slower in accelerating whilst the wing is engaged thus making it harder to catch the non-DRS car and get within the necessary 1 second gap in which it can deploy the DRS. This would also raise eyebrows because cars could be running in different configurations giving some onlookers the impression of disparity which could call into question the equality of opportunity amongst drivers.

Also, the device was conceived to spice up the action. They wanted to make sure it would get used in the races so allowing the use of it in qualifying forced the teams to use it as not doing so would hurt your qualifying position.


The DRS qualy rule is already giving us a reverse grid of sorts, the fastest car in race trim is unlikely to get pole now, you can optimise your DRS for the race or qualy, not both.

Top Tags
SEARCH Red Bull Racing