Ferrari Project 678 Speculation Thread

[MattLightBlue]

Wasn't this the same rumour that was debunked before? Why would you need a stronger/heavier alloy for an engine where the compression ratio will be lower?

Come on guys, we are better than in this on this forum. Stop with the compression ratio BS, even if true it is not the only factor at play for developing engines.
Increasing combustion chamber temperature and mep (i.e. mean effective pressure) are other ways for improving power and efficiency of an engine.

Come on you. The FIA lowered the compression ratio from 18:1 to 16:1 for 2026, on the face of it that doesn't necessitate a change to a much denser and more durable piston material. Quite the opposite.

What if it is a way to keep the temperature higher in the combustion chamber? You can also increase the pressure by acting on turbo operation, not only due to cr.
What I am saying is that I did some work for them that hinted in the steel direction, but not as described in the article.

[Seanspeed]

Actually Ferrari is usually one of the top 3 teams, with some notable exception. Sometimes first, very often second, a few times third, almost never last.

It was a metaphor of their mentality, not their actual results, they only care of winning nothing else matters, and often they are their own biggest enemy.

This is correct, but there are caveats about being the biggest team in F1. The pressure is huge, and lately they cannot handle it. If we had Toto all could have been great. The man could sell fish saying it is pork and everyone would believe him.

It's crazy to think that Toto would magically solve all of Ferrari's problems. lol

I dont see any indication Ferrari cant handle the pressure. They just need to build a better car.

[brakeboosted]

Come on guys, we are better than in this on this forum. Stop with the compression ratio BS, even if true it is not the only factor at play for developing engines.
Increasing combustion chamber temperature and mep (i.e. mean effective pressure) are other ways for improving power and efficiency of an engine.

Come on you. The FIA lowered the compression ratio from 18:1 to 16:1 for 2026, on the face of it that doesn't necessitate a change to a much denser and more durable piston material. Quite the opposite.

What if it is a way to keep the temperature higher in the combustion chamber? You can also increase the pressure by acting on turbo operation, not only due to cr.
What I am saying is that I did some work for them that hinted in the steel direction, but not as described in the article.

Knock becomes an issue well before steels higher melting point becomes beneficial. And typically for that, aluminium's heat rejection properties brings more overhead.

Turbo peak boost pressure is limited to 4.8 bar if I'm not mistaken. Same boost, lower geometric compression, very much points to lower peak cylinder pressures. I personally don't see why they'd move to steel. Then again, I'm not in Maranello. I do however expect to see an aluminium head the moment the covers are dropped.

[Sbrillo88]

Anyway, here In Italy almost every source talk about it and seems pretty legit, even the non-famous ones that are linked to Maranello in a way or another. Ferrari will use cylinder heads made of steel for their new PUs. It will not only steel btw.
Now I'm very curious about it.

[f1316]

It’s insane to me that the same people who were aghast that Ferrari could be running a higher fuel flow outside the times it was being measured could think that having a higher compression ratio outside the time it is measured is perfectly ok. Either they’re both bad or they’re both ok but fundamentally running to the measurement and not the regulation is the same in both cases.

[Holm86]

It’s insane to me that the same people who were aghast that Ferrari could be running a higher fuel flow outside the times it was being measured could think that having a higher compression ratio outside the time it is measured is perfectly ok. Either they’re both bad or they’re both ok but fundamentally running to the measurement and not the regulation is the same in both cases.

It was very literal in the regulations that the fuel flow must never exceed 100kg/h.
Tricking the sensors WAS cheating.

The 2026 regulations does not say that the compression ratio must be 16:1 at all times, only at ambient temperature.

So no, it's not comparable, at all

[dren]

Knock becomes an issue well before steels higher melting point becomes beneficial. And typically for that, aluminium's heat rejection properties brings more overhead.

Turbo peak boost pressure is limited to 4.8 bar if I'm not mistaken. Same boost, lower geometric compression, very much points to lower peak cylinder pressures. I personally don't see why they'd move to steel. Then again, I'm not in Maranello. I do however expect to see an aluminium head the moment the covers are dropped.

Fuel characteristics will play a role. Plus, these things run with knock sensors in cylinder.

[f1316]

It’s insane to me that the same people who were aghast that Ferrari could be running a higher fuel flow outside the times it was being measured could think that having a higher compression ratio outside the time it is measured is perfectly ok. Either they’re both bad or they’re both ok but fundamentally running to the measurement and not the regulation is the same in both cases.

It was very literal in the regulations that the fuel flow must never exceed 100kg/h.
Tricking the sensors WAS cheating.

The 2026 regulations does not say that the compression ratio must be 16:1 at all times, only at ambient temperature.

So no, it's not comparable, at all

I don’t have the precise regulations in front of me but I think you’re wrong that it states anything about ambient temperature. Ambient temperature is the measure not the regulation. The Race describes it as follows:

For the new power units that are coming, the regulations dictate that the compression ratio in a cylinder can be no higher than 16.0.

Presuming this is a good summary of the regs, “can be no higher than” means at all times, not only at ambient temperatures. They don’t have a good system of measurement for at all times and it is regulated how the measurement will take place - so the teams can indeed work backwards from that to decide what the limitations are - but the same is true if the fuel flow sensor only measures at defined intervals.

Edit: per Gemini, The exact wording of the relevant part of Article C5.4.3 of the 2026 Formula 1 Power Unit Technical Regulations is:
"No cylinder of the engine may have a geometric compression ratio higher than 16.0."

This says nothing about ambient temperature and absolutely means at all times, the same as the fuel flow regulation. So this confirms my point.

Philosophically this is totally the same.

[Holm86]

It’s insane to me that the same people who were aghast that Ferrari could be running a higher fuel flow outside the times it was being measured could think that having a higher compression ratio outside the time it is measured is perfectly ok. Either they’re both bad or they’re both ok but fundamentally running to the measurement and not the regulation is the same in both cases.

It was very literal in the regulations that the fuel flow must never exceed 100kg/h.
Tricking the sensors WAS cheating.

The 2026 regulations does not say that the compression ratio must be 16:1 at all times, only at ambient temperature.

So no, it's not comparable, at all

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

[f1316]

It was very literal in the regulations that the fuel flow must never exceed 100kg/h.
Tricking the sensors WAS cheating.

The 2026 regulations does not say that the compression ratio must be 16:1 at all times, only at ambient temperature.

So no, it's not comparable, at all

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

That isn’t the point. The point is that philosophically, designing the solution to be outside the regulation by ensuring it is only legal at the point of measurement is no different than what Ferrari allegedly did in 2019. Calling one “cheating” and one a clever interpretation of the rules - as has been several times in this conversation alone but also throughout media coverage of both - is hypocritical.

Arguably, there would have been no way to prove Ferrari’s engine trick if Ferrari themselves had not told the FIA - we don’t know for sure but that is the general understanding. So, to continue the analogy, perhaps it would require Mercedes and Red Bull to voluntarily do so as well? But ultimately it’s immaterial to the point.

[Holm86]

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

That isn’t the point. The point is that philosophically, designing the solution to be outside the regulation by ensuring it is only legal at the point of measurement is no different than what Ferrari allegedly did in 2019. Calling one “cheating” and one a clever interpretation of the rules - as has been several times in this conversation alone but also throughout media coverage of both - is hypocritical.

Arguably, there would have been no way to prove Ferrari’s engine trick if Ferrari themselves had not told the FIA - we don’t know for sure but that is the general understanding. So, to continue the analogy, perhaps it would require Mercedes and Red Bull to voluntarily do so as well? But ultimately it’s immaterial to the point.

We just disagree on that then, I do believe there is a difference on deliberately manipulating a sensor, and working with an unavoidable phenomenon (thermal expansion) to your advantage. Just like flexiwings, it's a grey area.

[bluechris]

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

That isn’t the point. The point is that philosophically, designing the solution to be outside the regulation by ensuring it is only legal at the point of measurement is no different than what Ferrari allegedly did in 2019. Calling one “cheating” and one a clever interpretation of the rules - as has been several times in this conversation alone but also throughout media coverage of both - is hypocritical.

Arguably, there would have been no way to prove Ferrari’s engine trick if Ferrari themselves had not told the FIA - we don’t know for sure but that is the general understanding. So, to continue the analogy, perhaps it would require Mercedes and Red Bull to voluntarily do so as well? But ultimately it’s immaterial to the point.

Exactly this and in the Ferrari situation they could had insist that that don't do nothing and call it a day. What would FIA do without knowledge? But the pressure from teams like MB where Ferrari embarrassed them in the engine area is too big.
Let's see what will happen now. For me it's the same as always with other "innovations" and i will repeat it again, it will stay for 2026 and forbidden from next year.

[saviour stivala]

Compression increase due to metal expansion was always the case. Those that did not run with compression increased above their designed ratio did so by control through design for a lower ratio at ambient temp to run at a target ratio at operating temp. This was always the case to control com bustion pressures at the higher ratios. If one can control combustion at higher ratios than what is mandated, one has no need to control by designing for lower ratios at ambient temp.

[matteosc]

It was very literal in the regulations that the fuel flow must never exceed 100kg/h.
Tricking the sensors WAS cheating.

The 2026 regulations does not say that the compression ratio must be 16:1 at all times, only at ambient temperature.

So no, it's not comparable, at all

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

What about a fuel flow? That can also change with time, maybe be higher when a sensor is not measuring. And in that case, how would you prove it?

This just to say: it all depends on where we put the bar at "cheating". The spirit of the rule is always bent, the question is how elastic is it?

[Holm86]

This post contains inaccurate information.

The 2026 regulations objectivelystate that compression ratio is not to exceed 16:1 on any given piston. Full stop. The mention of ambient temperature only describes the process by which CR is measured; it is not the rule itself.

Every engineer knows that nothing stays constant under changing conditions, that's also why flexiwings keep happening, because nothing is infinitely stiff, and the rulemakers know it. They can only design tests where a given load is added, and it's allowed to flex within a margin.

A volume will also not be the same at 20° and at 100°+, so if the compression ratio is 16:1 at 20°, it would still be as illegal if it's 16.01:1 at 100° as if it was 18:1 or 20:1 at 100°.
But how will you measure it to prove that ?? You can't with the current regulations, as there's no demand for in-cylinder pressure sensors.

So how will you even prove that Mercedes is increasing their CR that much with temperature?

What about a fuel flow? That can also change with time, maybe be higher when a sensor is not measuring. And in that case, how would you prove it?

This just to say: it all depends on where we put the bar at "cheating". The spirit of the rule is always bent, the question is how elastic is it?

By adding a second sensor out of phase from the first one, which is what the FIA did after finding out what Ferrari did.

If you add an in-cylinder pressure sensor to the regulations, you would find that NO engine has the same exact compression ratio at ambient temperature as it does at working temperature, so all engines would be illegal, as according to the regulations a compression ratio of 16.1:1 is just as illegal as 18:1 or 20:1