As explained in my post on ‘EBD’s’ – Exhaust blown diffusers (https://scarbsf1.wordpress.com/2010/06/25/exhaust-driven-diffusers/), teams blowing their diffusers rely on the throttle being open to keep airflow passing to the diffuser. Without this airflow, the diffuser loses downforce and the driver suffers a loss of grip or balance just as he enters the corner.
While careful design and how the exhaust is placed in relation to the diffuser, can alleviate some of the problems, any benefit from blowing the aerodynamics will be reduced when the throttle’s closed and no exhaust gasses are flowing.
It’s been reported that Red Bull are following a practice that was used on turbo cars (i.e. the old F1 turbos and WRC cars) to keep the turbo spooled up. By means of retarding the ignition when the driver is on the overrun as he slows for a corner. If Red Bull can keep the flow out of the exhaust pipe relatively constant, even when the throttle is closed going into a turn, then the diffuser will see a more consistent air flow and maintain downforce. Relieving it of the on\off throttle sensitivity so often a criticism of EBD systems. In effect an antilag system is trying to do the same as the Red Bull EBD mapping, maintaining a constant exhaust gas pressure, on or off the throttle.
When an engine is running normally, accelerating with the throttle open, the ignition of the fuel and air takes place inside the cylinder above the piston. The expansion of the gasses drives the piston and turns the engine.
During this process the gasses then escape into the exhaust pipe as the exhaust valves opens. As the burning has already occurred the gasses are some what cooler, the then temperature of the actual ignition. This means the exhaust gasses flow down the exhaust pipe with some speed and energy.
When a driver lifts off the throttle, the engine does induct much air, nor burn much fuel, as a result the engine slows and the exhaust flow also slows down. It is this problem that affects the diffuser, as it sees less exhaust flowing through it.
What Red Bull do is retard the ignition and maintain some throttle and fuel to allow combustion to continue to take place. However the ignition of the air and fuel mixture now takes place later in the engines revolution, when the exhaust valve has already opened. Rather than driving the piston down, the explosion of the mixture goes into the exhaust, still expanding as it does so. This creates a rush of gas through the exhaust mimicking the effect of running with the throttle open. Thus the diffuser still sees a flow of gas and maintains downforce despite the engine slowing down.
Of course this gain doesn’t come for free, the heat of combustion now takes place in the exhaust port, so that the exhaust valve, cylinder head and exhaust pipe all suffer excessive heat. This will affect them, as they cannot withstand this sort of thermal load for long periods. Equally the process burns additional fuel, in the race this is a negative thing as fuel is limited and no refuelling is allowed.
This ignition retard mapping would be controlled via the SECU via the driver selecting a steering wheel control, using quite normal tuning parameters and not some clever workaround. Of course this is all quite legal.
If the overheating issues can be contained, this would be a relatively simple mapping to introduce for another EBD team. As mentioned Renault Sport, Red Bulls engine supplier would have to know about this. Copying the concept, but not the actual SECU code would be quite easy.
i have a question though, would they be able to switch to this setting in the race for a couple of laps?
say just after a pit stop, or towards the end of the race to make a move?
n how soon before the others have such a mapping as well?
They coudl use it in the race, may be as apush to pass, not as a setting for a few laps. Its seems simple enough to develop, as long as the overheating isnt an issue
Why would this ever be a push to pass? It’s only gain is when you are taking the foot off the throttle, giving a more consistent and reliable output.
Re: Why would this ever be a push to pass?
– if it maintains a higher level of downforce when you’re off the throttle, then presumably it would allow you to brake later.
And you could use it to get more speed out of the corner before you intend to pass.
Do you have any reliable sources confirming it?
James Allen has mentioned it on his blog a couple of times, and he’s an F1 journalist of considerable repute so you could consider that a reliable source. It’s short of being first-hand information or something officially announced though.
I did not see anything about it on James Allen blog.
It’s mentioned here:
Unfortunately James’s site is playing up at the moment so I can’t get to the first time he mentioned it.
JA’s site is playing ball again now so I found the first time I saw it mentioned, which was after Valencia:
Sam Micheal confirmed it. And that they were talking to Cosworth about it.
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Shouldn’t we be seeing a side effect of excessive flames from the short exhaust system when this is in use?
The combustion phase in an engine is done quite fast. For a F1 engine I would suspect around 60 crankshaftdegrees or so from ignition to the flames reaching the outer walls and the main combustion phase being done.
Now, normally you want the combustion phase to be finished quite early so you can get peak cylinder pressure around 15-20 degrees after top dead center. That will normally provide maximum torque and efficiency.
If you instead retard the ignition to say 20 degrees after top dead center there will be a considerate loss of torque that have to be compensated by more throttle, but the combustion phase will still be done at around 80 degrees after TDC, which is before the exhaust valve opens. The temperature and pressure in the cylinder at the point when the exhaust valve opens will however be much higher than normal, and there is a higher massflow going through the engine.
Today, basically every production engine behave like this after a cold start, something used to fast heat up the catalysts to a working temperature; which can be done without noise or flames out of the exhaust.
The difficulty here though will be that the regulations state that the throttle must go between idle position and fully opened when the throttle pedal is fully released and fully depressed. So it is likely such a systems use will be limited to part throttle conditions.
But what goes against the use of such a system is that Renault would have to implement it, as it is an engine mapping job.
Wrong, Renault would not have to use it, they only provide the physical engine, not the tuning. Every team runs a standardized SECU made my Mclaren Electronic Systems and is responsible for their own engine mapping. The engine supplier can certainly help via consultation, but the teams set their own maps – not the engine supplier.
What kind of benefit is this system supposed to give?
Comparing Q2 and Q3 times I don’t see any jump in times for the Red Bull guys that’s different from any of the other drivers.
So I’d say, either they use this through the whole of qualifying or there isn’t much benefit at all.
Yep but you wood here it popping and banging a lot as the turbos did !!
The Mercedes of Schumacher in particular, was heard to have a rather raspy sound on corner entry when they started running the system in Valencia. It was even noticed by a fan in the stands, and texted to the practice commentators – they mentioned it on air. Obviously every team will have slightly different results, but this is indicative of the retarded ignition on over-run. He (Schumacher) was also warned during practice at Silverstone, that the SECU may pull the anti stall if you maintain too much throttle and brake at the same time (which is what would be required to keep the throttle plate open, and allow the airflow required for this system to work on corner entry.
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While it would certainly work the way you describe it, I doubt that this sort of system would be legal in F1. Both throttle valve adjustments performed by the ECU and continuous ignition timing adjustments could be used as at least a basic traction control system, and I can’t imagine that the FIA would want to open this can of worms.
The rules on throttles quite clearly outlaw it.
5.5 Engine throttles :
5.5.1 The only means by which the driver may control the engine throttle positions is via a single chassis
mounted foot pedal.
5.5.2 Designs which allow specific points along the pedal travel range to be identified by the driver or assist him to hold a position are not permitted.
5.5.3 The minimum and maximum throttle pedal travel positions must correspond to the engine throttle minimum (nominal idle) and maximum open positions.
They already use engine maps as a form of traction control. We saw Mclaren start to run an additional set of paddles beside their gearshifts the year before last – they are activated at the same time as shifts, and it pulls power out for lower gears to reduce or eliminate wheel spin.
If you drive a manual, then through the gears as quickly as possible without using the engine. Reduce your air conditioning use in the car, and low speed is a significant increase in the amount of fuel required for these systems macht. Stick to speed limits on the road you’re on. The faster you drive the more fuel you use. These steps, if followed correctly will lead to better fuel efficiency and reduce over all the bills.
it is sort of the equivalent of afterburner or rehaat thrust in a turbine engine. The more fuel they dump the cooler the parts will be until backfiring occurs? I wonder if any backfiring sounds have been heard on deceleration.
If the exhaust valve cannot stand much of this then the Red Bull advantage in qualifying my decrease in the race.
There was radio talk of Shumacher using throttle and brake at the same time which could be a way to maintine blown flow
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I guess if it weren’t for the engine freeze, the engine makers would be penning new designs with enhanced cooling to allow this to be used for longer periods.
In fact I wonder if they might be able to do that anyway, under the guise of reliability. Burn out a couple of exhaust valves, then you need to need to improve exhaust valve cooling to get your reliability back. It’s not going to be improving engine power after all.
How much it is worth?
Indeed. People can speculate all they want about “retarded timings”, but Red bull is consistently quicker with a low fuel car. Not just in Q3.
Sounds like you’re trying to seperate the technical developments from the pace? They are one in the same.
I’m saying that either the use of this engine mapping is not limited to Q3 and instead used at all times during qualifying.
Or alternatively if it can only be used in Q3 that there isn’t much gain. Seeing how there isn’t any extra gain for the Red bull cars going from Q1 and Q2 to Q3.
To be honest though, I haven’t a clue what you are trying to say. What does “seperate the technical developments from the pace” mean?
You are essentially saying that this technical development does not contribute to their pace. My question for you is then what precisely makes the car faster? It’s not just “faster” separate from the technical reasons for that speed – they are inextricably linked.
No that’s not what I’m saying at all.
If you check the times again, you will see that the red bull is the only car to consistently drop a half second between q2 and q3. Other cars have done it, but none as regularly as the red bull.
OK a list of average gains from Q2 to Q3 and Q1 to Q3 I’ve used the times from Barcelona till Silverstone (including)
Driver Q2-Q3 Q1-Q3
Mark Webber 0.4 1.1
Lewis Hamilton 0.4 0.9
Jenson Button 0.4 0.7
Sebastian Vettel 0.3 0.8
Robert Kubica 0.2 0.6
Fernando Alonso 0.2 0.6
Felipe Massa 0.1 0.6
Nico Rosberg 0.1 0.7
Michael Schumacher 0.1 0.9
So apart from the Merc drivers, Red Bull’s magic exhaust gains them on average 1 to 2 tenths at the max. Compared to the McLaren boys it’s an average of 0 tenths.
I performed a similar analysis, let me share my data:
I produced two averages of difference from Q2 to Q3.
The first average is uncontrolled, and includes all time differences where the driver logged both a Q2 and a Q3 time. Races in which the driver did not complete a lap in Q3 did not count towards the average. I included this set primarily to allow for verification of my data before i applied my “filter”.
The second average is controlled. I removed from analysis all lap time differences which were negative. That is – if the driver did not perform a faster lap in Q3 than in Q2, it was not included in the analysis.
I limited my analysis to three cars, for practicality:
Uncontrolled average: .132
Controlled average: .426
Uncontrolled average: .000
Controlled average: .477
Uncontrolled average: .220
Controlled average: .396
Uncontrolled average: .177
Controlled average: .294
Uncontrolled average: .180
Controlled average: .283
Uncontrolled average: .141
Controlled agerage: .216
I’m pleased with the results, because i think it shows a strong correlation between the improvements from Q2 to Q3 and the car.
Obviously many refinements could be made to the analysis, and i’m happy to hear criticisms.
Overall though, we can see that in some ways you are right, it only shows a gain of approximately 1 or 2 tenths – assuming all other Q2-Q3 changes are held constant.
However, this gain is produced consistently (atleast from the small pool of data we have) above and beyond the improvements shown by the other cars in the analysis.
I think we’ve misunderstood each other to some extent – I’m merely trying to say that obviously the Red Bull improves more in Q3 than other cars on the grid. (as is shown by both our analyses) This retarded timing system is part of the reason for that, i think. There is no magic bullet in F1, and i’m not asserting this is it, merely that the improvement is logically linked to a technical difference on the cars.
So you “correct” away the numbers that disagree wih your premise and then arrive at the conclusion you were looking to find 🙂
And still you are left with at best only one measly tenth advantage from a seriously small and unreliable datasource. Hardly something to go screaming about that this is the ultimate answer as to why Red Bull is so much faster in qualifying.
Especially when you note that on average they are 4 tenths faster than everybody else in qualifying.
If anything, I’d say the reason the Red Bulls score their gains from Q2 to Q3 more consistently is because their car is so much better and that it’s so much easier to drive.
You’d much sooner see Alonso, Hamilton or Button mess up their second Q3 run because their car is much more difficult to control. Let alone drivers like Massa, Rosber or Schumacher who struggle to get their tyres to work in qualifying.
Also, I think Webber and Vettel are better qualifiers than the other drivers are. They are much better at the “time trial” aspect of F1 than Alonso, Hamilton and Button are. The strengths of the world champions lies in their “race brains” which results in consistency and their overtaking skills.
So all in all I still maintain that it’s a marginal effect at best and with the lack of data it cannot even be attributed to that single car improvement.
“So you “correct” away the numbers that disagree wih your premise and then arrive at the conclusion you were looking to find”
Welcome to the basic premises of statistics. You want me to include in my analysis, runs in which Vettel’s suspension arms broke? You think this gives a more accurate measurement of his cars improvement?
I tried to be civil, and your numbers are *wrong* but i didn’t want to criticize you. Go take some statistical analysis classes and call me.
You’ve “corrected” your data aswell, both by limiting the scope of the races you’ve analyzed, and limiting your accuracy to one decimal place.
You’ve also failed to calculate correct averages for several drivers, not to mention the misrepresentation of the data by limiting accuracy.
Button’s average, using your Britain-Valencia limits is actually .319 – not .4.
Webber is actually .478 – not .4 – maybe you just haven’t learned the “rounding up at 5 or more” rule yet – s’allright, you don’t learn that till like grade 4!
So according to your criticisms, my data is wrong because i didn’t include sessions in which the car failed – wet qualifying sessions – and sessions in which the driver did not make it to Q3.
But your data is wrong because you can’t do math. So i guess we’re even?
Ok lets draw a close to this here and now, people. Lets agree to disagree with the figure work.
Pffft. He’s trying to be civil.
I can’t help it that you cannot read.
BTW how much is .477 – .396?
Besides, I calculated the qualifying difference over the whole season and that’s around 4 tenths for Red Bull.
Anyway, back to the actual discussion. You are not “correcting” the data. You are showing that the data is useless. You just don’t take it far enough.
For instance, In Monaco Hamilton was hindered in Q3. In Valencia he nearly spun off in Q3. So lets “correct” those times away. Amazingly now Hamilton is on average .538 faster from Q2 to Q3. McLaren must have something even better than Red Bull has for Q3 …
Besides, even if we would assume that this one tenth of Q2 to Q3 advantage for Red Bull is significant, you still haven’t shown that this gain is because of retarded timing.
It could also be because they don’t put much effort in Q2. Or use because they use old tyres in Q2. Or because the Red Bull car is so much easier to drive. Or because the Red Bull drivers are qualifying specialists.
So we are seeing a probably insignificant difference which cannot be directly related to retarded timing.
No matter how much math you do and however “polite” you are, there is no escaping that.
Oh sorry, I didn’t see your reply scarbs.
Still, did you figure about what the advantage of this retarded timing would be and/or if it’s really only used in Q3?
I’ve had it confirmed that its being used, but I have no direct info if its used in all Q sessions or indeed for the Q full lap…
In terms of advantage I guess its a tenth or two, I’m told by Jean Claude Migeot the benefit is mainly in slower corners, so its advatage is clearly circuit dependant.
Indeed the gain in Q3 seems to be quite similar between the two drivers for the Red Bull drivers. So that does indeed seem circuit related.
I have taken the “corrected” averages of “Q2 to Q3 gain” (of Red Bull drivers) and the gap in qualifying per track (best Red Bull to first non Red Bull). I’ve sorted the list by “Q2 to Q3 gain” to show correlation.
Race Q3-Q2 Qualy Gap
Australia 0,2 0,2
Canada 0,2 -0,3
Valencia 0,4 0,4
Monaco 0,5 0,3
China 0,5 0,4
Turkey 0,5 0,1
Silverstone 0,6 0,8
Spain 0,7 0,8
Bahrain – 0,1
Malaysia – 1,3
Apart from Canada (tyres) and Turkey it seems the Q2 to Q3 gain corresponds pretty well with the advantage they have in Q3 against the competition.
The odd thing is then though that it seems that it’s actually the high speed tracks where they are gaining most in Q3 and not on the slower “street” circuits.
Thanks for confirmation scarb
Yeah, good to know the teams don’t see this as a huge thing either. Or at least not the explanation for Red bull’s afvantage in qualifying.
Although for Renault a one tenth advantage could mean a couple of places on the grid.
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can we see it on other cars in Hockenheim?
I wonder if the Renualt engine updates pre-season helped accommodate this slightly.?
Anwyay, Sam Micheal has confirmed this theory btw.
Not my theory, just the engine mapping one. 😉
did Webber crash reveal red bull secret as Michael say?
Overheating of exhaust components would not be a huge problem, as the time in use ie braking into a corner, is
short. Exhaust flames would not be visible, as turbos
tend to smooth out pulses and prevent flames passing.
Uhhh… F1 cars don’t run turbos?
Password protected posts?
Yes, I had trouble with my laptop and had to use the blog to send some info rather than via email.
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