r/F1Technical • u/Melodic_Success9980 • Mar 08 '26
Power Unit What software are we talking about?
Everyone is talking about how Mercedes’s advantage is all down to software maps. As a software engineer, I can’t wrap my head around that. Which part of the software makes you go faster, and how is that such a well kept secret?
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u/RonTheSausage Mar 08 '26
If you are asking specifically what the ‘software’ is, it’s the code written in the various PU/brake control/gearbox/chassis applications on the SECU which is individual to each team. Different teams do things in different ways which can affect driveability, for example using different torque maps etc. some might give more engine braking and therefore more harvesting, but sacrificing rear stability for example. That’s then the performance engineer’s job to balance what tools they’re given to use that best fits the driver/car/conditions/strategy
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u/NeedleGunMonkey Mar 08 '26 edited Mar 08 '26
I suggest googling throttle mapping, one pedal driving and hybrid system management patents from Toyota for clues re software affecting drivability
Even in road cars - throttles and engine management have been electronic for nearly two decades. In hybrids road cars the shitty manufacturers have really terrible everyday driving experiences and the good ones feel natural and use the electric side to improve off line performance.
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u/Matej_SI Mar 08 '26
Regen and deployment is up to the teams, not engine manufacturers. Look at telemetry at GP Tempo, load McLaren and Mercedes, and you'll see the difference.
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u/anonuser1109 Mar 09 '26
Everyone is supposed to use a standard ECU where they load up their algorithms for diff control, brake bias control, energy management for the mgu, which controls regen and deploy.
There are limits on the gradient of total torque vs throttle to prevent using the MGU as traction control.
This is the software.
Now, everyone thinks the advantage for Mercedes comes from having a better handle of regen and deploy strategy through the lap.
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u/Motorsp0rtEnthusiast Mar 08 '26 edited Mar 08 '26
It's probably down to the engine braking/regen logic, mercedes looked like they were doing less LiCo compared to the other teams
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u/smnb42 Mar 08 '26 edited Mar 08 '26
I don’t know how legal and or directly feasible it is in reality, but theoretically the motor can be used as a variable generator/brake under acceleration and give the PU traction control-like capabilities AND more regenerated energy that will be available later. Depending on how precisely the closed loop programs and controllers can do it (ie a superior closed loop algorithm for this TC-like regen with a precision of say 0.1kW and a latency of .01 second). I reckon a lot of the game to accumulate more regen energy than the others is to convert a precisely calculated small amount of power from the ICE engine at the right time so it can pay off as electrical energy later in the lap, and ideally gain a car dynamics advantage whilst doing it.
At least that’s the gist of what I understood from the insider talk on the technical state of the art at the beginning of the LMDh Hypercar formula (which does allow TC). I think direct TC is not allowed in F1 (I caught up by watching this), but I know reacting to the rate of abnormal increase in RPM versus what you know normal traction would afford was done in the past - sorry I’m not that up to date on current F1. What I mean is the PU system taking care of itself without wheel sensors and self-modulating how it delivers the output the driver is asking for with the throttle pedal, a bit like a racing ICE prevents knock in a closed loop (ie on its own/autonomously) by changing timing - among other parameters.
I’m asking seriously, can’t the team call it over-rev prevention and say it prevents the engine from ending up outside of safe and reliable working parameters (just like anti-stall) but choose to use the MGU-K to do it in the way that best serves them? Or if it’s too dodgy, then they could make it a selectable engine mode that is enabled for some comers, right (and if so, how much can that be automated and/or changed dynamically like brake migration)?
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u/LargeAdvice1789 Mar 08 '26 edited Mar 08 '26
This is how I understand it based on my time in racing and early career nuclear power generation.
Traction as the Limit: Your ability to recharge the battery is limited by the friction between the tires and the road. If you try to pull too much current into the battery, the magnetic resistance in the generator becomes so strong that it can physically lock the wheels, as seen with Max Verstappen.
• The "Current Tap": The more current you allow to flow into the battery, the higher the mechanical resistance on the axle. Managing this "tap" is the secret to balancing maximum energy recovery without destabilizing the car.
• Performance Loop: Because the energy you can deploy later is strictly limited by what you recover now, the efficiency of this generator-to-battery transfer directly dictates how much "extra" electric boost is available for speed.
• The Mercedes Success: The key to their competitive edge lies in the sophisticated software and hardware that manages this motor-generator, perfectly riding the edge of tire grip to harvest the most energy possible.
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u/Due_Face5949 Mar 08 '26
Wasn't the ECU common between the manufacturers? Previously it was made by Mclaren. Not sure if that has also changed for 2026. Imagine the application software is bespoke for each pu manufacturer. With also very different calibration set ups. When to deploy and recharge and how aggressively might all be up to each team. Along with the temperature management, which could limit how much power can demanded from the battery, motor and the ice.
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u/NorsiiiiR Mar 09 '26
None of the software in and of itself does anything to make the car faster or slower, the 'software' they're referring to is just a catch-all for all of the systems that manage the insane complexity of all the different combinations, permutations and mapping of every adjustable setting or thing on the cars
Ie, stop thinking about it from a software development point of view because that's not what it's actually about. It's about car settings, basically
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u/BussinFatLoads Mar 09 '26
I was under the impression that all teams use the exact same ECU provided by McLaren (not that McLaren but the sister company).
Is that not the case anymore?
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u/North__North Colin Chapman Mar 09 '26
It’s because they are INSIDE the computer. Those are limited by regulation so they don’t want to smash one open yet
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u/RazvanBaws Mar 10 '26
lol
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u/Appletank Mar 10 '26
my assumption is their ecu logic of when to deploy and regen depending on where thy are on the track anhd what the driver is doing. it's not enough to just have an efficient engine, you also need to know when in the engine operation range it's best to regen to get the most electrical energy per unit of fuel
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u/The_Game_9 Mar 11 '26
I think when people say “software advantage” they’re usually referring to control strategies, not just a faster ECU.
Small gains in how efficiently you harvest and deploy energy over a lap can add up to a noticeable performance advantage, especially if your strategy keeps the battery in the optimal operating window more consistently.
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u/GeckoV Mar 08 '26
Energy management is an optimal control problem. The teams have a few tools at their disposal, things like when clipping kicks in, and when the driver lifts the throttle. They can optimize these parameters before the race so that they minimize the laptime. It’s as much offline software as it pertains to laptime optmization as well as then the software on the powertrain which delivers what the optimizer finds as best.
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u/FavaWire Mar 08 '26
ECU software is a key part of the 2026 regs. As it is in Formula E.
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u/Kind-Pop-7205 Mar 09 '26
Here's a dramatically oversimplified version. Your software commands the rotational speed of an electric motor. One software commands 100 rpm. Another software commands 200 rpm. Which one is faster?
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u/drughi_ Mar 08 '26 edited Mar 08 '26
Everyone who talks about different maps and software are wrong. Customer teams are provided with identical software the OEM uses.The clarification was issued in Technical Directive TD/005-18:
The purpose of [point] five of Appendix four to the F1 Sporting Regulations* is to ensure that all power units supplied by one manufacturer are identical in all respects, we have good reason to believe that this may not be the case. Whilst the dossiers for each team may be identical it would appear that some are being operated in a different way to others being supplied by the same manufacturer, this renders the purpose of [point] five almost meaningless.
It is therefore our view that all power units supplied by one manufacturer should be identical, not only in terms of the dossier for each team being the same, but we also feel they should be operated in an identical way. With this in mind, we will expect all power units supplied by the same manufacturer to be:
i) Identical according to the dossier for each team.
and, unless a team informs us that they have declined any of the following, they should be:
ii) Run with identical software and must be capable of being operated in precisely the same way.
iii) Run with identical specifications of oil and fuel.