2014-2020 Formula One 1.6l V6 turbo engine formula

[diffuser]

I'm having trouble parsing that. It's proven on this forum but its contents must not be detailed in this thread?

https://www.racefans.net/2018/02/23 ... titive/

Given identical physical components, and at the time different fuel, oil, and perhaps software, how could a works team operate their engine differently?

Fuel chemistry for superior combustion properties
Oil either as it pertains to a combustion aid or sliding friction reduction
Software may have and may still require the capabilities of a works team to fully exploit

A flaw in this regulation: capability of similar operation does not guarantee similar operation.

How else might the factories operate their engines differently?

Customer can run it differently IF wants to. Not vise versa.

[NL_Fer]

Because it is the suppliers engineers deployed at the customer team, who decide which engine mode can be used and for how long. Those numbers are also different for every team, because how the cooling design is, how many laps in high power modes are used during Q, etc.

The engineers can decide that Hamilton can use strat xx for 20 laps and Perez for only 5 because of those differences.

[diffuser]

Because it is the suppliers engineers deployed at the customer team, who decide which engine mode can be used and for how long. Those numbers are also different for every team, because how the cooling design is, how many laps in high power modes are used during Q, etc.

The engineers can decide that Hamilton can use strat xx for 20 laps and Perez for only 5 because of those differences.

Or as in the Austria GP ..the opposite.

[roon]

·Is exhaust manifold pressure typically higher than intake manifold pressure? For these engines.
·Is exhaust gas retention in the combustion chamber relied upon?
·Is charge air relied upon in any unique way to cool the combustion chamber? For example, whenever backpressure is reduced in the exhaust manifold via the wastegate, non-combustion air could flow across the CC and the exhaust valves during valve overlap.

[gruntguru]

·Is exhaust manifold pressure typically higher than intake manifold pressure? For these engines.

Yes. They want to run back pressure as high as possible to maximise MGUH recover - without compromising the engine performance and reliability. A degree of scavenge would still be possible courtesy of (variable) tuned intake and highly optimised flow paths throughout the intake and exhaust.
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·Is exhaust gas retention in the combustion chamber relied upon?

See above (and below). There is little or no benefit.
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·Is charge air relied upon in any unique way to cool the combustion chamber? For example, whenever backpressure is reduced in the exhaust manifold via the wastegate, non-combustion air could flow across the CC and the exhaust valves during valve overlap.

I am confident that even with the wastegate closed there will be some charge air exiting the exhaust valve. This is possible even with BP higher than MAP thanks to wave tuning. The benefits are significant, especially for an engine that is almost certainly operating at thermal and pressure-rise-rate limits.

[hurril]

·Is exhaust manifold pressure typically higher than intake manifold pressure? For these engines.

Yes. They want to run back pressure as high as possible to maximise MGUH recover - without compromising the engine performance and reliability. A degree of scavenge would still be possible courtesy of (variable) tuned intake and highly optimised flow paths throughout the intake and exhaust.
·Is exhaust gas retention in the combustion chamber relied upon?

See above (and below). There is little or no benefit.
·Is charge air relied upon in any unique way to cool the combustion chamber? For example, whenever backpressure is reduced in the exhaust manifold via the wastegate, non-combustion air could flow across the CC and the exhaust valves during valve overlap.

I am confident that even with the wastegate closed there will be some charge air exiting the exhaust valve. This is possible even with BP higher than MAP thanks to wave tuning. The benefits are significant, especially for an engine that is almost certainly operating at thermal and pressure-rise-rate limits.

What does that mean? I have never heard of a _rate_ limit in this context.

[godlameroso]

Compression ratio.

[63l8qrrfy6]

No, the heat release rate is very high and as such mechanical (gas pressure) and thermal loads are far greater compared to a conventional engine.

[roon]

I understand it as the rate at which pressure increases in the CC around TDC due to combustion. More generally it might be inclusive of compression ratio. The manufacturers are likely trying to combust the fuel as quickly and as near to TDC as possible, so "at the limit." Beyond which I assume it starts being classified as knock or detonation.

[saviour stivala]

The cylinder developed pressure (pressure on top the piston as a result of combustion) is certainly at thermal and pressure rise rate limit. A limit only made possible to operate at by the development of the in-cylinder knock sensor enabling the operating control capability. While these engines are reputed to be running at or near an 18:1 ‘static’ compression ratio, the resultant ‘dynamic’ compression ratio is part and parcel of the combustion pressure developed result. The dynamic compression ratio (‘corrected’ compression ratio) is less than the static compression ratio. The difference will depend on intake valve timing. It will be higher with ‘earlier’ (soon after) BDC intake cam timing. It will be lower with ‘later’ (late after) BDC intake cam timing. The present turbocharged engine needs far less drastic valve timing and certainly much less valve overlap than the previous 18000rpm NA engines.

[Tommy Cookers]

.....The present turbocharged engine needs far less drastic valve timing and certainly much less valve overlap than the previous 18000rpm NA engines.

how's that ?

the present turbocharged engine presumably has both inlet and exhaust pulse tuned lengths aka wave tuning
these together should increase VE by about 20% - (ie by the same proportion as NA's does)
this 20% means much-reduced compressor work and much more H recovery (compared to a non-tuned length)
this 20% will not develop without similarly 'drastic' valve timing

the exhaust tuned length effect must substantially act from a point upstream of the turbine (downstream would be weak)
(and of course the small ram effect from the car's speed will not increase proportionately)

with continuous control of H rpm there is little or no downside to 'drastic' valve timing
'drastic' valve timing may even be beneficial to reduce throttling for partial powers - somewhat like the Prius
and such timing might even be kinder to the valve drive and springs

[hurril]

I understand it as the rate at which pressure increases in the CC around TDC due to combustion. More generally it might be inclusive of compression ratio. The manufacturers are likely trying to combust the fuel as quickly and as near to TDC as possible, so "at the limit." Beyond which I assume it starts being classified as knock or detonation.

Ahh, makes total sense!

[saviour stivala]

“Exhaust and intake pressures”. “Regardless of the aspiration method. The goal of the cam/valve timing design are to optimize cylinder filling and exhaust removal”.
A larger turbo on a small engine will need more RPM to get the most out of the turbo.
As turbochargers have evolved, not only their compressor side got more efficient, but so have the turbine side. These modern turbochargers still cause restrictions in the exhaust tract, but will bring back pressure down to a level equal to the pressurization of the intake tract. Dealing with similar pressures on both sides, with high-density charges on both sides, moving the system to a more similar to a naturally-aspirated model. So piston motion can be used for some wave tuning to get the charge motion at a lower velocity and with less ‘valve timing’. With the more efficient turbine section of modern turbochargers, the intake and exhaust pressures are back to a 1:1 ratio. Although elevated from a naturally-aspirated application, the equalized pressures allow camshaft designers to apply ‘some’ of the theories behind N/A camshafts to turbo cams. With these modern turbochargers there is still an exhaust restriction – there’s no getting around that fact –but they bring the restriction level to that of the amount of boost they are providing the intake tract. That 1:1pressure ratio is what allows wave-tuning to come into play,

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Noli nothis permittere te terere.

[godlameroso]

How would intake pressure be similar to exhaust pressure, when exhaust pressure has the benefit of combustion heat increasing the volume and pressure of the gas?

Is pumping work greater at the ICE or turbine? Can this ratio be played with to bias one over the other during race conditions?

If MAP is 4 bar, these same ~4 bar would be seen at the exhaust + temp induced volume/pressure increase. I imagine these engines have larger than normal exhaust valves.

[gruntguru]

“Exhaust and intake pressures”. “Regardless of the aspiration method. The goal of the cam/valve timing design are to optimize cylinder filling and exhaust removal”.
A larger turbo on a small engine will need more RPM to get the most out of the turbo.
As turbochargers have evolved, not only their compressor side got more efficient, but so have the turbine side. These modern turbochargers still cause restrictions in the exhaust tract, but will bring back pressure down to a level equal to the pressurization of the intake tract. Dealing with similar pressures on both sides, with high-density charges on both sides, moving the system to a more similar to a naturally-aspirated model. So piston motion can be used for some wave tuning to get the charge motion at a lower velocity and with less ‘valve timing’. With the more efficient turbine section of modern turbochargers, the intake and exhaust pressures are back to a 1:1 ratio. Although elevated from a naturally-aspirated application, the equalized pressures allow camshaft designers to apply ‘some’ of the theories behind N/A camshafts to turbo cams. With these modern turbochargers there is still an exhaust restriction – there’s no getting around that fact –but they bring the restriction level to that of the amount of boost they are providing the intake tract. That 1:1pressure ratio is what allows wave-tuning to come into play,

A few points on the above post.
1. Turbo efficiency has been high enough to produce positive pressure differential (MAP > EBP) for many years. And yes modern turbochargers are ever more efficient.
2. Wave tuning has the same benefits for all engines - even for a negative pressure differential engine. The benefit of wave tuning on such an engine is to reduce the effective "negative pressure" - in the best case, a negative differential engine can still have positive scavenging during valve overlap thanks to wave tuning.
3. The current formula one engine in self sustaining mode is almost certainly in this category. To maximise MGUH harvesting, the exhaust back pressure will be as high as possible consistent with effective scavenging of the combustion chamber.

Camshaft selection and valve timing must be a nightmare for the engine developers when you think about the range of pressure ratios they have to deal with. In self sustaining mode the pressures are likely 4 bar MAP and 5+ bar EBP. In electric supercharger mode probably 4 bar MAP and 1 bar EBP. I am sure that variable valve timing would be a huge benefit. I have no idea why the rules prohibit this in what is supposed to be an "energy efficient", "road relevant" formula.

Taking this one step further, I believe that full ECU control of valve events is just around the corner (eg Koenigsegg "Freevalve" system). Loosening the rules in this area (perhaps with compulsory sharing of technology) would help develop this tech to "road ready" stage while delivering perhaps 5-10% race fuel reduction and even greater benefits for road cars.