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Silverstone tech- The story behind Red Bull wing and McLaren diffuser
Silverstone tech- The story behind Red Bull wing and McLaren diffuser
Posted By: James Allen  |  12 Jul 2010   |  7:47 am GMT  |  81 comments

This weekend we have been at Silverstone, a classic track but one that has undergone a facelift for this season with new sections on the second half of the lap.

As usual there were plenty of interesting technical updates on the cars, with teams catching up on the trends of the season and adding either exhaust blown diffusers or drag reducing F Duct rear wings, or in the case of Williams, both.

Following on from the rush of exhaust blown diffusers we saw coming onto the cars in Valencia, McLaren had been working towards Germany but fast tracked the update and brought theirs to Silverstone for testing in Friday practice. It was the main feature of a major upgrade package, along with a new front wing.

The system means that the exhaust outlets need to be placed lower near the floor of the car and this causes some problems with overheating the rear suspension, if you are not careful.

Red Bull pioneered the technology and has really maximised it. They blow the exhaust gas through a slot which energises the airflow through the diffuser. It is this slot which the Red Bull mechanics are so keen for people not to see when the car is on the grid. But this is a bit of a pointless exercise, as teams have photographers taking digital images of the cars as they drive down the pit lane!

One of Red Bull’s secrets is a setting on the Renault engine for use on the final crucial lap in qualifying, whereby the ignition is retarded on the over-run, which maintains exhaust gas pressure even when the driver lifts off the throttle. This maintains the performance of the blown diffuser and keeps the downforce up when it’s most needed. It thus avoids the main problem of an exhaust blown diffuser whereby when a driver lifts off the throttle for a corner, the downforce goes missing when you most need it and the rear stability changes.

It’s not something you can do for more than a lap or two as the temperatures go sky high, which damages the engine, but it gives that vital fraction of a second which keeps Red Bull ahead of the rest in qualifying.

But one of the problems with running the exhausts low is that the components at the back of the car get very hot. McLaren’s lower wishbone featured a wide insulating cover to prevent overheating. The side sections of the diffuser featured an upper insulating plate, and underneath and they were painted with an insulating coating. But these precautions didn’t prevent the diffuser slightly changing shape due to the high temperatures, and this caused some rear end instability. So the diffuser was dropped for this weekend and McLaren had a rush on to balance the car with the new front wing but without the rear end package.

Their performance in the race on Sunday was quite remarkable given how much work there was to do after Friday’s problems.

Red Bull Front wing

The standard wing Webber qualified and raced with

The most talked about technical story of the weekend was the decision by the Red Bull team to use its new front wing on one car only, that of Sebastian Vettel. The team brought two of the new units to Silverstone, but the one on Vettel’s car broke a mounting during Saturday morning practice. So the team decided to take the wing off Webber’s car and put it on Vettel’s car for qualifying and the race, which angered Webber.

Vettel's wing on the Silverstone grid

The pair had been doing comparison tests during practice and the team says that Webber and his engineer were not sold on the new wing by the time the decision was taken. The new wing has two main visible differences; it has a double slot on the side of the end plate and the horizontal plate at the outer edge of the wing is also double.

Ferrari updates

Ferrari brought an update to its rear suspension at Silverstone, to cope better with the overheating issue caused by the blown diffuser.

Increasingly the teams use Friday as a test session for new components and if they perform well they may continue on the car for the rest of the weekend, otherwise they may be taken off and used again at a subsequent event once some refinement has taken place.

On Friday, for example, Ferrari did a comparison run of the two cars with Massa using the drag reducing rear wing in the morning and Alonso using it in the afternoon. It was decided from that test to use the F Duct wing for the remainder of the weekend and Alonso managed to qualify third on the grid with it.

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About the best blog ive ever read, fascinating discussion mid way thru about exhaust gases and LJK’s logical conclusion.


Great article James. Thoroughly enjoyed it. Informative comments as well.


I noticed that the engine sound of the Red-Bull was somewhat different to all the other cars at Silverstone. In particular, when on the “overrun” when the thottle is off, the Red-Bull unit was coughing and spluttering noticeably more. I’m wondering if there is some use of different engine mapping in the race or if something different is happening with the (pressure or route of the)exhaust gasses.


It is interesting about the ignition retardation. Would Red Bull they use this during the race also? The reason I ask is just before the collision in Turkey Vettel was told to ‘push button to pass’. Like many, I thought that this was a team order for him to pass Webber. Perhaps it was an instruction to use the ignition retardation to give him the extra grip and speed that he needed. If they can only use it for a lap or two, and with the team radio being broadcast a lap or so behind would this be a good fit? Just a thought.


Hi James – a bit off topic but you are probably the best person to ask – what is going on with FIA Post Event Technical Reports? The last few races it is there, or not, or incorrectly linked.

I enjoy reading this report as it gives an insight into F1 not really reported elsewhere – could you please shed some light?


Don’t know. I’ll ask the FIA


Thanks James!


Hi James,

Quick question how did the rest of the paddock find out about the engine retardation?

Was this leaked by engineers from RB or from Renault?? Or is there a delicate engine note difference from the Renault engine during qualifying??


I am sure some of the engineers can hear the difference. Plus, since it is a system used on other race cars past and present, it wasn’t far off to make an educated guess.


I do wonder how it got out about the redbull engine mapping.

Was it engineers looking at the car in corners and listening, or renault who knows about it?

It’s just an interssting route and always fun to see how these things evolve.


I think they were probably listening, or maybe noticing flames or blackish smoke on a hard qualifying lap, signifying fuel burning in the exhaust pipes… although I haven’t seen photos of exhaust over-run, so it’s hard to say.


i think James mentioned cameras in the pitlane. But for this kind of detail, there was probably some human factor involved in letting the cat out of the bag – F1 looks like the last few places where old style industrial espionage is still useful; i just wonder to what extend.



any insight into how close Mike is to getting a Renault engine for next year?

What an absolutely massive boost that would be for Lotus push up the grid.

I very nearly bought an Elise recently (unbelievable handling), but after about 30 miles I was ready to take it back to the showroom 😉

My ears were bleeding…


I think they are talking seriously to them, but also talking to Williams abourt buying the back end/hydraulics/gearbox etc with the Cosworth, a bit like Force India do with the McLaren-Merc back end.


Hi James,

Do you have any info on other teams copying this engine switch that Red Bull are using in Q3?

Any news on which other team might get it first? Indeed, were McLaren going to be using it if they got their blown diffuser fitted?

I’d really appreciate knowing.



Can’t shed any more light, I’m afraid, at this stage


Very off topic but I was just wondering if anyone else facies being Martin Brundle on twitter?


That’s about as off topic as it’s possible to get!


I know and I’m sorry but I was just following it on twitter, why are people pretending to be him?

Back on topic, I’m absolutely fascinated by the technical stuff, love to hear about the innovation in the sport. There are a couple of other places I used to go for my fix but they tended to get a bit too technical (I’m not an engineer after all) but this use pitched just right for me.

The comments also tend to explain things through the lively. discussion from people who do understand


Another gem of an article James …. thanks and well done. I could never understand why there was such a proformance drop in the RB6 between Saturday and Sunday.

Chris Partridge

Fascinating — another superb piece of technical journalism. Is this over-run of the engine one reason then why Red Bull have been blowing their engines (no pun intended)?


probably the reason for the first blow up when Alonso inherited the lead from Sebastian.


Hi James,

I forgot to add 1 more question.

Roughly how much time do the drivers gain from the advantage of this setting on the Renault engine?


Hi James,

A very interesting post which leads to a couple of questions in my head.

Your post seems to suggest that the Renault engine is the only one that has this special engine map that allows retarded ignition over-run. If so, how do Ferrari and the other teams with the newly introduced exhaust blown diffuser cope with the rear end instability when the throttle is lifted?

This brings to my next question and pardon me if it is a stupid question. If the Mercedes engine does not have this setting, can it be easily incorporated?

If it is not easily incorporated, how is Mclaren going to solve the problem of rear end instability during braking and make this update work in 2 weeks in Hockenheim when this is exacerbated by the warping of the floor due to the high temperatures of the exhaust?


All the teams are working to stabilise the systems, that’s where some of the performance differential is at the moment. Red Bull have a head start. Two rival engineers told me that they are working on emulating the ignition trick.

zidane the great

But the trick is for one lap only? But how do they keep car stable during the race? Is it only overheating and deformation of diffuser that cause instability?


I think it’s just something that gives maximum downforce for that one lap, the rest of the time the thing is pretty stable anyway, as you can see from the TV pictures. Red Bull were flat through Copse and Abbey this weekend, no one else was


Up until the last two races the stewards were doing a fantastic job. Letting the races be decided on the track without interference. What changed? Last race we see the passing of a safety car was handled with an insignificant drive through penalty 20 minutes after the episode occured giving the offending car had enough time to build up a time that negated the penalty and then we get the same penalty for an illegal pass? A car that passes on off the track is supposed to give the place back. If the other car fails why is it a drive through? Makes no sense. A drive through costs you 25seconds or more… letting a car repass you is less than 5 seconds at most. Why did penalty take over 20 minutes to be handed out and the other penalty in less than 3 minutes? I know there are people that say the FIA used to favour Ferrari and others that will say the ex-racing stewards that are British are favouring the British drivers and this maybe true or not. But if somehow the FIA with all their infinite technology and 50million camera angles can make an immediate decision and have a consistent penalty for each infraction there would be no need for stewards and their bias. The camera and telemetry doesn’t lie.


To be fair, in Valencia it was more important for RC to tend to Mark Webber than chase down marginal misdemeanors – so that was always going to be a delayed decision. About the overtake, you may recall that at Spa 2008, Lewis lost his lead post race even after giving Kimi the place back – so in a way you could argue the stewards were quite lenient at Silverstone.


That was only because he didn’t really give the place back properly – he wouldn’t have been able to overtake there unless he cut the chicane.


Fascinating to hear about the RB blown diffuser. A simple yet ingenious solution.

To think there was all that guff at the beginning of the season about magic suspension for qualifying.


Great info on the Renault engine and the Maclaren blown diffuser, why oh why cant the Beeb tell us things like this instead of pathetic films of the presenters doing barbecues and pub quizzes.

Well Done James for giving the fans what they want.


Those mappings are designed by the users of the ECU, not the supplier of the ECU. Each team can design their own mappings which will vary depending on how they set up the car.

Every car is a different combination of components, and the ECU controls all sorts of things about the engine, not just the fuel, but valves, gearbox, clutch differential and all sorts so it would be impossible for the teams to work with a truly fixed ECU.


The race to develop the car is getting hotter.

Ferrari seems to have a good rear package when they introduced the blwn diffuser, while McLaren has struggled a bit.

The interesting thing is that the modifications to the rear need to be adjusted in the front as well, making the car change the way behaves and reacts.

I think the biggets winner of the upgrading are Mercedes and Williams, seems that the have increased their performance more than everybody else percentage wise.

Ferrari has still issues with the general handsling while following another car, Alonso have caught a number of cars but unable to overtake them despite the clear overall speed advantage.

Ferrari looks like Red Bull last year, unable to be fast unless in clear air.

As I mentioned before I think McLaren could be faster than Red Bull for the end of the season, if they can adjust the blown diffuser they look in very good shape.

But I am looking forward to see Force India in Monza and Spa as well

zidane the great

James, do you know why only Mclaren had such big problems with instability when throttle was lifted. Other teams seem to know how to fix this. Maybe complexity of MP4-25 rear end, wrong calculations or they are just clueless like they were first half of last season? I guess we’ll find out soon


It wasn’t just off-throttle. If you watched Button and Hamilton’s on-board views, the rear end was twitchy all over the circuit. It was just bad balance, and they couldn’t fix it during the weekend. They planned to have the blown-diffuser, and adjusted the aero balance to suit… but when they took it off, the car was far too loose.


probably they didnt have enough time to set the car up after removing the new package. My guess is they would have had a better car on the old package if they had not tested the blown diffuser. However it was important for them to run the new package and test it so it was a give and take.


Exactly. My post wasn’t too clear, but that’s the point I was trying to make. I think I got distracted mid-post… 😉

It was set up to take advantage of the additional downforce on the rear from the blown diffuser. When they removed it, they lost rear grip but still had all the front grip, making the car a wicked oversteering beast.


james hamilton sayed that redbull were 4 or 5 tenths faster than his mclaren in the race. with ferrari looking alot better than mclaren this weekend up to the race point and nico rosberg saying alonso was more worrying behind him than button how close do u think ferrari would have been in the race. for a track that should be one of the best for redbulls car if ferrari were alot closer maybe we still cant rule out alonso this year either


Button wasn’t attacking as hard as he would other wise have done because he had to conserve fuel. He opted for a safe 4th rather than a risky 3rd which was reasonable given the circumstances. What lacked from the Ferraris was a Vettel-like blitz through the slower cars. Alonso is a much better over taker than Vettel so its confusing we did not see him emulating Vettel and may be collecting a point. I expected some really dramatic driving after he told his engineer to shut up.


I think the force India in the hardest car out there to overtake. It has great initial burst out of the corner and is very fast in straight line. I think if alonso had of got passed the force India he would have got as far as sutil. You seen how much bother vettel had in passing sutil in the force India aswell


How does the Renault engine have this special engine map that allows retarded ignition over-run when they use the standard ECU?

I think this is disinformation. Any blown diffuser system that needs exhaust gas flow to maintain DF seems like an invitation for handling instability. The driver must be free to correct with the throttle at all times. Methinks the main gain is by purifying the flow going under the rear wing whereas it was previously disturbed by the exhaust gases exiting high enough to change the low-pressure zone under the rear wing elements a bit. Lowering the exhausts (which McLaren used to do in the 1998/99 title winning cars) places the gas flow into the already turbulent area besides the rear wheels and may even help fill the low-pressure void of the rear tire’s wake increasing slipperyness.


The ECU is standard, the programming of it is not.


Yes the programming is std. They have a selection of around 11 different maps that are pre-programmed. Beyond that they may not tinker.


Yes, the maps are pre-programmed, but not by McLaren, by the teams. That means that they could have one of the maps programmed to do what is described here.


I have checked it with engineers from three other teams and I can assure you that it is true


I think there must be more to it than this.
In order for the engine to pump out gas through the exhaust, it must draw gas (air) into the engine. Normally, on a trailing throttle the throttles (be they slides, flaps or whatever) are closed, so no air can be drawn into the engine and no gas will be pumped out of it!
I surmise that they are also doing something with the throttle to allow air to be drawn in (and therefore pumped out). The retarding of the ignition is to ensure that the power generated is minimal (not sure why they don’t just shut off the fuel on overrun, but it may be something to do with cooling and/or lubrication).



I think the pneumatics only close the valves, I think a camshaft still opens them.


Good explanation.

Retarding the ignition and basically getting some mixture ignition very late, probably even resulting in combustion in the exhaust itself (as suggested elsewhere in this post), will destroy exhaust valves pretty quickly. I think they are doing this, but can do it for only very limited time before they have to let the valves cool down


By ‘throttle’ I mean the pedal the driver operates and whatever action that has. Obviously it’s all fly-by-wire these days so there is no mechanical connection to the throttle butterflies/slides. The whole point of “getting out of the throttle” (as Mr Brundle likes to say) is to modulate or reduce power. When braking for a corner you don’t want the engine pushing you on. So if the airflow isn’t being reduced (throttle butterflies/slides not being closed) then the only way to cut engine power is to make the mixture hopelessly wrong (cut/reduce the fuel) and/or make the ignition timing hopelessly wrong. On a road car you run a lot of ignition advance on the overrun as you get poor cylinder filling leading to a slow burn (so you need to start the burn earlier) – failure to do this results in popping & banging, which obviously isn’t a concern on a race engine.

So I guess what they are doing is some combination of keeping air flowing into the engine by not closing the butterflies/slides and reducing power by running extremely suboptimal fuelling and ignition timing.



It’s pretty much how a ‘Bang-Bang’ works on WRC cars.

So there must be some kind of throttle bypass to keep air flowing and retardation on ignition to keep the pressure on the exhaust gases up.

It’s not really all that new an idea, it’s just ‘new’ again for F1. And using that to keep the flow going on a diffuser, I think that may be totally new.


The ‘throttle’ may be nothing of the sort, however, with pneumatic valve operation, surely? There is no need for a physical throttle and, hence, no need for a reduction in gas throughput.

As regards a simple fuel cut-off, that will only result in the same volume of air being moved, not in the same consistency of air – temperature, exit speed from exhaust, and so on.


The throttle controls the amount of air going into the engine (along with the amount of fuel & ignition timing). As the throttle is closed the amount of air reduces, hence the amount of exhaust gas reduces. When the throttle is completely closed there will be little or no airflow and little or no exhaust gases irrespective of the ignition timing. There must be something else going in if this is a genuine tweak – is there any more techie info available?


Lot of punctures this race.

Vettel’s puncture might have been due to the ever more complicated wing end fences that the teams are using. When the rounded end fence rule was envisaged to avoid punctures it was imagined that there was a simple structure. Now although there are limits on the “sharpness” of the wings, the flips and slots, (all the stuff that was banned on the bodywork and has now migrated to the front wing), are relatively delicate and easy to shred – leaving sharp carbon shards to return the favour in spades.

With Renault producing a gazillion wings a month to be competitive, perhaps these highly complex end fences should be outlawed for cost saving and to reduce the likelihood of punctures.


Mclaren are feeling the problems with the introduction of the blown diffuser that the others were feeling with the F-duct, not the same thing but not easy to make solution right away without testing.

James how good a F-duct system work on a car like the Red Bull at a place like Silverstone?

They looked very fast on the straights specially compared to other places.

About the wings of Red Bull i was expecting that the new wing would get broken again on the race.


“The pair had been doing comparison tests during practice and the team says that Webber and his engineer were not sold on the new wing by the time the decision was taken.”

Is this actually true? If so, Webber has absolutely nothing to complain about.


But he did complain – so who is lying? Interesting also that Ferrari claim Race Control did not get back to them while Charlie insists he told Ferrari about three times to hand the position back to Kubica. Once again, who is lying? Ferrari are starting to operate like a panicking team. Let’s see how it goes in Germany.

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