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Formula 1 engine mapping – Your questions answered
Posted By: James Allen  |  29 Jun 2011   |  10:03 am GMT  |  67 comments

There has been a lot of talk lately about engine mapping, what with the changes made for Valencia and for Silverstone.

In Valencia the FIA outlawed the changing of engine maps between qualifying and the race, while from Silverstone onwards teams will have to rework engine maps and throttles so that there is no more than 10% throttle opening blowing exhaust through the diffuser when the driver lifts of the throttle pedal.

We’ve all got very carried away with talk of engine maps, but one reader,
Gondokmg, from South Africa, pulled us up and asked us to explain. He posted these extremely good questions the other day. So I took them to our friends at Mercedes-Benz and they were happy enough to put forward an engineer to explain.

What is the difference between an engine map (like what the FIA have now prevented teams from changing between qualifying and the race) and an engine mode (like that Vettel had switched on just before he crashed into Webber in Turkey last year) ?

Mercedes: “There is no accepted universal definition of what constitutes a map or a mode, but we draw a general distinction between a ‘mode’ and ‘mix’ settings: what the question refers to as a ‘map’ we would refer to as a
‘mode’, and what the question calls a ‘mode’ we would call ‘mix settings’.
Generally we accept that by “mode” we mean a broad description of a regime under which we run the engine. This defines the philosophy of ignition mapping, fuelling and the distribution of fuel cut strategies used to
achieve the torque that the driver demands. This is what the teams were no
longer allowed to change between qualifying and the race in Valencia.

Engine “mix” settings are detail changes to fuelling that are routinely
used during the race to reposition ourselves on the curve between fuel
consumption and engine power.”

For a race like Valencia where the off-throttle EBD is still allowed,
what stops a team like Red Bull from replacing their extreme engine map
with an extreme engine mode (still part of the race engine map) for use in
qualifing and also in the race for brief periods (e.g. at the start to
create a gap, to overtake or to defend a position)?

Mercedes: “Crucially, because all teams now use a common engine management system, there are limitations as to what any team can change with the car on-track, and these are only the engine “mix” settings. Fundamental changes to engine “modes”, where teams may chose to put aggressive or fuel-inefficient strategies into their cars for qualifying, can no longer be made for the race with the car in the garage or by the driver on-track.”

Thanks very much to Mercedes for reaching out to help bring this fan a little closer to the sport. I hope many others among you benefitted from this insight too.

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Seems to me that F1 has severe problems with its terminology. What is used by the professionals in the sport and what is used by commentators/journalists seem to differ quite a lot in some cases (such as the mix/mode issue above). Take a look at tyres for a clear example; in the sport there's terms such as option, prime, wet and full wet but for the layperson it's much more common to use softer, harder, intermediate and wet.

I guess there's not much to be done about this but it's a shame nonetheless.


i guess the commentators/journalists use the terms softer/harder rather than option/prime keeping in mind that there is a first timer out there watching the race.

it makes sense...think of a kid who has started watching Formula 1 and he could easily distinguish that there are two tires....


The weird thing with regar to tyres is that one wold expect that the prime tyre is the optimum one to use. In reality, drivers and teams usually prefer the option tyre...


I just ignore the coments re tyres, it's too confusing! Why can't they just use the terms "soft, medium, hard, wet, intermediate, dry, slicks, treaded, etc. etc." as we've been used to for decades? What does "Prime" mean? Does it last the longest, or is it the fastest around a lap, or is the one the teams get the most of, or is it the cheapest or the cutest?

Too much for me, that's for sure.

It's a prime day here in Christchurch today with the sun shining, but I have the option of going to the west coast where I bet it's raining.



sounds like a nice job for a piggy back ECU lol.



How about a Power FC? And associated hand controller? Hey! There's an idea! Use it for the planned turbo engines! 😛

Karl Hurd, Campbeltown

Still none the wiser!


There are many tech savvy readers here with imaginations. We've seen the $30-50K dollar steering wheels with screens. I bet FIA has one heck of a time policing this.

I can see a nice "smart" steering wheel that is able to put the car into various extreme mapping settings for purpose of quali, or a map which has a time execution period - meaning run this map loop 30 times, then end loop, move back to regular map. I could even see a program map that makes the ECU delete itself after execution loop to prevent detection depending on hardware capabilities in this black box - which obviously has processing power, memory, etc.

Of course someone could even have a steering wheel with cheat mode - UP DOWN, UP DOWN, LEFT RIGHT, LEFT RIGHT, A B, A B, START - and you're in extreme mapping mode for a lap. 🙂

I don't see how this can be stopped until the ECU is a ROM only device, coded by the supplier, with code being reviewed by FIA prior to upload to ROM approval. This should be sealed, not upgradable, and fixed for the season - that's the only way I can see control of this issue.


This type of situation is well documented - "secret menus etc". Ferrari were caught out over ten years ago with a launch control "mode" activated by a secret sequence of steering wheel buttons. It was discovered by routine data/software analysis by Liverpool Data Research of ecu logging data sent by the FIA - this firms day to day business is the testing of nuclear power station software for bugs/programming errors. The different terminology - map/mode is deliberate - to create a "grey" area as to what is and isn't within the "rules"!


Not sure if that's even possible, but nice Bubble Bobble reference regardless! 🙂


The ecu is a control item. The access the teams get is limited. The fia have full control and can review how the ecu is used. This is my understanding of the ecu drawn from various sources.


When I refer to the ecu I am talking about the hardware not the software running on it. The teams create the map. The ecu just runs it. The fia must of had their own experts look at the software on the ecu and decided it was against the regulations.


Actually a replt o the other Mark but won't let me go further down the tree.

The teams can modify the maps not the ECU itself. The map/mode will give you lots of engine parameters that you can reprogram when plugged into a laptop. The in race mix changes use a small subset of engine parameters that can be controlled by individual switches/actuators.

The ECU's are all standardised and provided by McLaren Electronics. They are sealed units and the actual board and controller software cannot be modified.

On top of that the ECU has loggging so any changes would be detectable by the FIA post race.


With that being the case how do teams modify them to provide the exhaust run off gasses over the diffuser?


...what does one need a loop for in that context?

James, do you have any idea (or do Mercedes fancy sharing) precisely what information the ECU provides the FIA, and when?


Another question.

What is 10% throttle opening?

Is it angular opening of a butterfly or barrel,linear opening of a slide,cross sectional area of the inlet tract, or some digital reference scale?

How are the FIA going to monitor whatever it is?


It isn't actually 10%, FIA has said it will be 10%, or the minimum required in '07 to get idle, this may be different for butterfly and barrel etc, no one type will be discriminated against, they use the 2007 specs beccause the engines are the same, but they were not blowing in '07.


Great post and thanks to Mercdes as eventhough I had a fair idea of the "mode" scenario wherein you draw the maximum performance from the car for one or two hot laps by abusing the tyres, fuel, engine and the ignition system to the extend you could but never quite understood how they play with the "mix" modes though had an idea what revup and revdown meant.

Good one James!


Excellent tank you James and Mercedes.


i think there is still a loophole post silverstone. The regulations say that when the driver is off the throttle there can no longer be exhaust gasses passing through.

As the drivers all use left foot braking, they could drive through corners with a trailing throttle open and thus the hot/cold blowing rules don't apply.


They can always program the clutch to be dis-engaged in the turns, thus allowing the throtle to remain opened, thus blowing gases from the exhaust. No?


Nice idea, but big potential for wear maybe. But that is the same idea as a centrifugal clutch.


If memory serves correctly, the seamless shift gearboxes they've all been using for the last 5 years means that clutches are only ever used at the start and pitstops so not an option.


The brakes would get to hot using that method


Ha! That is a very good point... What is preventing them from opening the throttle considerably when the throttle is barely pressed? Even retarding the timing in this scenario to prevent the generation of torque but still energize the exhaust gases. Unless we are going back to the snorkel exhausts.


I think that's what's coming next year with the dimension I seen

Garry J. Berry

It is not an option for a driver to brake with one foot and press the accelerator with the other.

As I understand it, prior to the ban fuel was being pumped into each cylinder when the exhaust valves opened and the piston was rising to push-out the burnt combustion mixture, this fresh dose of fuel was then ignited by the retarded spark timing in order that combustion occurred with the exhaust valves open so that the expanding force from the explosive second-stage combustion did not push the piston down but accelerated along the exhaust system very quickly, over the diffuser and thereby created an enhanced 'hot-blown' downforce.

If the driver accelerated and braked together 'normally' the exhaust valves would not be open (due to the restriction on 'falsely' timing of fuelling and spark by retarding the ignition) and the downward forced piston would continue to drive the wheels whilst the brakes tried to stop the wheels rotating. One would be acting against the other.

This would result in ‘cooked’ brakes and/or little net braking force resulting in an inevitable accident.

The FIA have not stopped the diffuser being blown by the exhaust during 'normal' exhaust gas emissions, just the false over-run blowing by fueling and ignition during the exhaust cycle of each cylinder.


...except that if they did that the engine would be generating torque as the throttle is being activated. Therefore engine tries to push car in straight line while cornering - oversteer/understeer, take your pick - either way you're first on the scene of the accident.

When off-throttle, torque is not generated because the spark occurs when the piston is in it's exhaust stroke. In this phase, unburnt fuel (rather than exhaust gasses) is pushed out of the cylinder. Hot blowing means that this fuel is then ignited before the exhaust valve closes thus igniting the fuel which is now in the exhaust system (energised).

This is why they can't do it all the time because of the abuse it causes to the engine.


Would it be possible to have two throttle positions that give tangible feedback to the driver? Ie. one 1cm in which doesn't actually give drive but does keep the throttle open to use the hot/cold diffuser blowing, while beyond that the actual torque/power request gets sent to the engine?


On second thought, that could potentially be classed as driver-adjustable aero I guess, seeing as how hot-blowing the diffuser has been outlawed as movable aero.


They could but that would be quite inefficient from a fuel consumption perspective and would likely lead to exponential brake pad temperature increments (and resultant wear), not to mention potentially making the differential redundant. A bit of trail braking and overlap throttle is part and parcel of every (good) driver's technique anyway.

Having said that and to digress a bit, in racing karts, to keep the revs up within the sweet-spot for optimal torque and to balance the kart out through high speed corners, drivers do lean on the brake a lot through the corner.


Thanks for a very useful post. Love the new design!


I don't understand the answer to the 1st question :

ignition mapping : is that the timing of the ignition ?

distribution of fuel cut : does that mean how much fuel & when fuel is injected into cylinders for ignition ?


yeah igntion mapping is basically saying when exactly the spark plug should fire. I think its mapped against the throttle position and is relative to Top Dead Centre IE when the fuel/air mixture is at maximum compression.

The fuel distribution is the map of when to inject fuel and for how long. This is used to control the Air/Fuel Ratio.

You use a combination of the 2 to make your engine run more efficiently by running lean (reduction of fuel in comparison to air) but changing this also means you need to change the ignition map to cope and it also leads to a reduction in horsepower and torque output.

Difficult to explain without knowing how much you know about the inner workings of a 4 stroke engine and the suck,squeeze,bang,blow principle.

Francesco Lanza

It probably will hurt red bull more than other because they say red bull are more advanced with this system, but the question is will it affect Ferrari and Mclaren to? I think so, red bull will lose performance but so will Mclaren and Ferrari there for red bull still will surely have the faster car no?


Largely depends on whether Horner was telling porkies when he claimed they're not hot-blowing. If he wasn't, they'll lose a lot less relative to Ferrari and McLaren than many expect. Either way, it could potentially upset the whole balance of the car, as by Adrian's admission it's a key part of the concept.


All teams using a blown diffuser will lose performance. If RBR are gaining an advantage of .5s from theirs, while Ferrari and Mclaren gain .3s from theirs, yet Ferrari and Mclaren are .2s down on pace compared to the RBR, all cars are now theoretically equal in terms of pace.


Thank you for this new design that I find most clear and practical. I finally found my favorite blog of f1. I just change my computer screen and I make my choice for the 2011 Championship:

I hope that Jenson will win more races this year ...


I cant get my head around this! The best i can come up with is that the best off throttle blowers will loose most in qualifying as they don't need to carry many laps worth of extra fuel. I guess we will see if the RBs Q3 performance come mainly from blown defuses, or DRS or both!

Andrew Halliday

This is the sort of story that make JAF1 stand out from the rest. It's great that you can put a general reader's questions to one of the teams, well done James keep up the good work.


Thanks James, when time allows an even more in depth dissertation on engine control would be appreciated.


I suspect the new regulation would also cover "cold blowing", where the fuel flow stops under a closed throttle, but incoming air still flows into the cylinder and is pushed out at great force by the pistons. Thus, the blowing into the diffuser does not involve "exhaust gases" per se.

Red Bull claims they have never used "hot blowing" as some of the other teams have, but only "cold blowing". If so, they may be affected far less than some other teams.


This proves that the FIA is just clamping down on way too detailed stuff to even the field (is that what F1 technology is about?).

Let's just say they will all go slower some more than others.

The thing is though, if in Silverstone RBR are dramatically slower (meaning they won't finish in top 2) and this continues, many will see it is the FIA manipulating the outcome of the championship to gain more viewers.

If anyone but Vettel/RBR win the titles, it will be considered a hollow title because the FIA fixed it with this. It would have been perfectly normal to ban them from the next season...not half way (F-duct, DD/DDD, etc).


Yeah but who want's Wetal to win, anyway? Not me!



FIA didn't ban something on the RB7. They banned a certain feature which all or almost all teams are using.

As I understand this, Renault would suffer the most, not RedBull.

Nobody is trying to stop RedBull in particular. I am a Ferrari fan, but I hope all these measures are not directed to slow RedBull. It won't be fair.


Understand that engine mapping of all sorts was devised by Lucas Industries many years ago because computers in those days could not calculate injection timing and fuel timing fast enough to keep up with engine speeds, load etc. An engine map is like a look up table and much faster to use than an algorithmn. Takes a fair bit of testing to map it out properly.


Ahhh! You spoke the name of he who must not be named! I'm going to have to go read some NASCAR news now to clear my brain now, thanks to you.

Before you ask. Yes I do drive a British Leyland era Jaguar. Why else would I have such a reaction.


Don't tell me your Lucas Opus control box stuffed up!


Graham Passmore

Based on the response from Mercedes-Benz, it seems to me that 'mix setting' adjustment on the modern F1 car is an electronic equivalent of manual choke adjustment such as we used to have on our road cars in the decades gone by, and that I still have on my gas engined lawn mower & snow blower.


Cheers Graham, I'd completely forgotten about the lost art of "manual choke adjustment" on road cars... and what a bind it was 🙂 Gawd bless my little ol' 205 - long may it rest in "garage heaven".



do you (or your contacts) have a feel for if the Renault engined cars or Merc/Ferrari will suffer more.

I'd heard the Renault system (as the first ones to do mid last year) was more effective/advanced.

As in if 0.5 (Helmut Marko) second per lap comes off redbull, does only 0.3 come off McLaren and therefore a relative gain.

I'd also always thought that the Cosworth cars didnt the retarded system, but that is actually not the case. They do.

All very interesting. We'll see in the coming weeks.

Thanks, Andy

P.S See you tomorrow at MTC.


I thought I'd read somewhere that Christian Horner had said Red Bull didn't use hot blowing so they would be unaffected? Could be a smokescreen of course....

Suspicion is that McLaren and Ferrari do use hot blowing so if CH is right then RBR may actually have a bigger advantage when this is implemented.

Not sure it was right to tinker with the regulations part way through the season. I can see the sense in banning it as it is wasteful and leads to a development war that has no real benefit outside of F1 (assuming you take the view that F1 technology should eventually filter down). Not sure of the costs of constantly changing engine mappings (or whatever they are called), exhaust outlet designs, changing cooling methods, etc but I'm sure its not cheap. But given that the FIA were planning to enforce "normal" exhaust outlets, etc next year they could have just waited.


Sorry probably not the best area for this.

On min 3 of qually 3 for Rosberg Martin brundel said Rosberg hit the soft limiter. What is a soft limiter??? I've heard of a limiter but what is a 'soft' limiter???


He was refering to the 18k RPM if I remember right.

And so were the Ferrari. I was actually keeping an eye on those RPM.



It's the engineers' jobs to make their car go faster. If this is done in a safe way (i.e. not by using your hand to cover of a hole in the cockpit - F-duct) and they do not break their annual budget doing so consuming more fuel, then who can be against it? By the way, if you burn more fuel, this would imply that you would need more fuel at the beginning of each grand prix, thus carrying more weight. The net benefit from the hot blown diffuser has to be there. In this context, I say all credit to the engineers, too bad the FIA wants to punish the inventive minds in this wonderful sport.


Is it any wonder anyone new to F1 can be totally put off? Re mapping,mode,mix,ECU. Its beyond many and to add each team has a different interpretation,surely mode is the outcome,re-mapping is the way,and mix is the combination,why make it so complicated....


F1 is supposed to be the high-tech form of car racing after all, so you would expect it to be complicated..


The FIA is only involved in the matter of off throttle blown exhaust as a favor to Ferrari just as it was in 2006 when it deemed illegal the Renault Mass Damper as a moveable aero device.


>in 2006 when it deemed illegal the Renault Mass Damper as a moveable aero device

Which was such a travesty that words failed me. Might as well have said the steering wheel was one too, since it moves the front wheels which definitely affect the aero.


I thought Ronspeak had disappeared. It is alive and well at Mercedes.


With the engines working less, due to no off throttle use, I wonder if the time lost by having less downforce, will be offset by having to carry less fuel for a race, thereby having less tyre wear too. Either that, or they'll have more fuel to play with, letting them run the engines with a higher fuel mix anyway?


Do we know if teams use different engine settings for different tracks?

For example, how does a low speed circuit like Monaco compare with a high speed circuit like Silverstone? More power, more torque or always a combination of the two?


Theres a fairly simple solution to all this. ban the buttons on the steering wheel apart from for the drs and kers. You dont then need to worry about wording.

AND ideally make them change gear again but thats just a personal dislike of flappy paddles.


Although it will no doubt be intriguing as to who gains and loses amongst the "big 3" teams, I'm most interested in Renault. They went a completely different way with their side exiting exhaust layout to which I assume they'll face either a bigger relative gain or loss compared to the teams around them. It will be interesting to see whether they establish themselves as the 4th team so to speak and jump ahead of Mercedes, or on the flipside whether the effects result in that bad a loss that they're in the clutches of the midfield battle and losing out to Force India, Torro Rosso and maybe even Sauber and Williams in the lower points places.

If you James or anyone has any theories regarding whether Renault's layout leaves them in a better or worse position relative to the others or whether it'll be negligible please do share.


No wonder nothing changed in Valencia if the definition is so broad brush.

I bet the engineers found the loopholes before the rule even came.

Sounds like the whole system needs holomoginising thingy wotsit doodle-ing. (Can't speel).


I think they should be allowed to blow all they want. Hot, cold whatever. They just need to introduce a rule whereby the exhaust exits *behind* the car, thru a round pipe, after all the aero and bodywork. Too easy 😉


That (rear exit exhausts)is in the new rules for next year as far as I know but its not a quick fix for the engineers so what we have from Silverstone is very much a sticking plaster as it were. Thats how I see it anyhow.

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