Talking to a turbo expert

[WhiteBlue]

Since the both engines are essentially undifferentiated up to the max power of the NA engine, the efficiencies are very similar.

The important point is that a NA engine will always be compared to a smaller turbo engine of lower capacity and probably also lower cylinder count because in road car and racing applications the engines are marketed and compared on the same power level. If you compare engines with the same power output the turbo engine is the more fuel efficient alternative.

As an example please compare the McLaren MP4-12C with the Ferrari 458 Italia and the Lamborghini Gallardo LP570-4BP.

The Ferrari has a 4.5L NA V8 with 570 bhp and .41 hp/kg power/weight ratio
The McLaren has a 3.8L Turbo V8 with 592 bhp and the same .41 hp/kg p/w ratio
The Lamborghini has a 5.2 NA V10 with 562 bhp and a .42 hp/kg p/w ratio

McLaren claim that their engine has the lowest per hp fuel consumption of all existing cars. Educated guesses put the fuel consumption 15-20% lower than the Ferrari with the NA engine. The Gallardo with the huge V10 is heavier and even thirstier than the Ferrari. It is no match in terms of driving fun and fuel bill for the McLaren. It is simply for enthusiasts who must have a big thirsty V10 engine for emotional reasons. Rational people will buy the McLaren.
This is what I'm talking about.

[olefud]

Since the both engines are essentially undifferentiated up to the max power of the NA engine, the efficiencies are very similar.

The important point is that a NA engine will always be compared to a smaller turbo engine of lower capacity and probably also lower cylinder count because in road car and racing applications the engines are marketed and compared on the same power level. If you compare engines with the same power output the turbo engine is the more fuel efficient alternative.

This depends on whether the selling point is efficiency or power. I’m just addressing the physics of the two alternatives. True the turbo has been optimized to sell efficiency while maintaining power. But if efficiency were the prime concern, the same size NA engine would most likely prevail.
But I agree that marketing is driving the turbo.

[WhiteBlue]

This depends on whether the selling point is efficiency or power.

The selling point is the better car with more driving fun and lower environmental impact. The McLaren buyer can be proud that he is buying the best you can to protect fossil fuel reserves. The Lambo buyer just feels he needs a huge engine to serve his ego.

[Tommy Cookers]

So what are these new engines going to be?

Changing the BSFC to 235g/KW*h I come up with .37% BTE engine only and .45 BTE with 100KW added.

Now that would be a game changer!!!

Ringo's recovery turbine power was 84 bhp, equal to about 75 bhp (56kW) delivered from motor action ?
I think this causes a (very small) loss of crankshaft power

[Tommy Cookers]

Does mean that the pumping losses of the engine are reduced

the notional pumping losses are only reduced in engines with a favourable pressure difference
(eg typical road engines having low boost)

the 2014 F1 will have pressure differences that increase notional pumping losses
(in smaller part due to the boost level ie independent of compounding and larger part due to the compounding from the turbine)

about 1000 free-piston engines were built (where all the power was taken from the turbine, ie none from the pistons)
would we call that pumping losses ?

[pgfpro]

So what are these new engines going to be?

Changing the BSFC to 235g/KW*h I come up with .37% BTE engine only and .45 BTE with 100KW added.

Now that would be a game changer!!!

Ringo's recovery turbine power was 84 bhp, equal to about 75 bhp (56kW) delivered from motor action ?
I think this causes a (very small) loss of crankshaft power

Thanks TC for the correction I forgot that WB post in this thread was before ringo's new turbine data.

So with 56kW it would be around 41% BTE Still a major improvement!!!

[riff_raff]

the notional pumping losses are only reduced in engines with a favourable pressure difference
(eg typical road engines having low boost)

With regards to an exhaust turbine, we should remember that it also effectively increases the expansion ratio of the exhaust cycle. A good way to improve cycle efficiency.

[ringo]

Since the both engines are essentially undifferentiated up to the max power of the NA engine, the efficiencies are very similar.

The important point is that a NA engine will always be compared to a smaller turbo engine of lower capacity and probably also lower cylinder count because in road car and racing applications the engines are marketed and compared on the same power level. If you compare engines with the same power output the turbo engine is the more fuel efficient alternative.

This depends on whether the selling point is efficiency or power. I’m just addressing the physics of the two alternatives. True the turbo has been optimized to sell efficiency while maintaining power. But if efficiency were the prime concern, the same size NA engine would most likely prevail.
But I agree that marketing is driving the turbo.

No the same size NA engine cannot prevail. That is if both have the same power output.
If you have a 2 litre engine with only 150hp vs a turbo charged one with 300hp then i'd agree the NA one is more fuel efficient.

[olefud]

There are, to my mind, two previously developed issues here. The first is whether turbocharging enhances the thermo efficiency of an engine. To design an experiment, it would seem that heads-up comparing two otherwise identical engines would be the better course. Displacement is an intrinsic engine characteristic while power is quite variable and rather extrinsic. But of course reasonable minds can differ.

The second is whether the purpose of turbocharging is to increase power rather than efficiency. Again, comparing two otherwise similar engines would seem to be more meaningful if the question is truly about efficiency versus power.

What characteristics an engine needs to sell is more a social, market acceptance issue than a technical one. Marketing a product is something that I admit evades me.

[WhiteBlue]

There is no doubt from the examination we have made of various cars that turbo engines easily extract more power and have the lowest fuel consumption per horse power. The NA engined cars tend to have more power to weight issues when they go to extreme power and cylinder count. The turbo cars show a little less responsiveness and have the inferior sound characteristics. The responsiveness may catch up though as soon as we see more hybrids with electric compounding like the new 2014 formula. I look forward to the impact of that technology on the super car sector. I bet it will spawn a few turbo driven super cars in short terms.

[pgfpro]

http://autospeed.com/cms/title_Turbod-f ... ticle.html

"Implications

So let’s take a step back. In the comparison shown above of the two 2-litre engines, the turbo engine has better fuel economy, better CO2 emissions, 50 per cent more bottom-end power and 34 per cent more top-end power.

In short, it’s better in every respect (except, it must be said, cost to build)."

[WhiteBlue]

Great source pgfpro!!!
The same source says:

Modern engines using well matched turbos and other technologies like direct fuel injection are capable of exceeding the performance of larger naturally aspirated engines across the full rev range – from just off idle all the way to the redline. Their immense bottom-end power and intrinsically higher thermal efficiency also allows them to develop much better real-world fuel economy. As turbocharging is a technology already well developed and understood, expect to see a lot more turbocharged, downsized petrol engines performing for all the world like big engines – but without the thirst and emissions production.

And Bosch confirm our turbo expert from Garrett:

As part of the downsizing concept for the engines of the future, exhaust gas turbochargers are one of the key technologies for achieving a sustained cut in fuel consumption and CO2 emissions. The use of exhaust gas turbochargers is already common in modern diesel engines, and they are expected to become more prevalent in gasoline engines as well.

[Agenda_Is_Incorrect]

http://autospeed.com/cms/title_Turbod-f ... ticle.html

"Implications

So let’s take a step back. In the comparison shown above of the two 2-litre engines, the turbo engine has better fuel economy, better CO2 emissions, 50 per cent more bottom-end power and 34 per cent more top-end power.

In short, it’s better in every respect (except, it must be said, cost to build)."

The NA 2.0 FSI is a joke of an engine, VW doesn't even know where to use it now a days. It's not economical, has performance way far than what was expected from it and compared to other competing engines (even non DI ones) of similar size it lacks. VW had to put a turbo on it not to be behind, it's still a not very economical engine. Honda achieved the same horse power with much less fuel consumption out of their 2 liter NA engine, which is also more reliable, the only advantage is the VWs stronger bottom end

Don't take this personally or as an attempt to deny turbo engines their advantages, I'm pointing that there are too many misconceptions on this subject and making a point for mr. WhiteBlue

McLaren claim that their engine has the lowest per hp fuel consumption of all existing cars. Educated guesses put the fuel consumption 15-20% lower than the Ferrari with the NA engine. The Gallardo with the huge V10 is heavier and even thirstier than the Ferrari. It is no match in terms of driving fun and fuel bill for the McLaren. It is simply for enthusiasts who must have a big thirsty V10 engine for emotional reasons. Rational people will buy the McLaren.
This is what I'm talking about.

I suppose you have driven all of them to say that it's no match in terms of driving fun? Or you drive the same 4 cilinder (maybe 3) boring economy box every day and do a wild guess that the "green" engine must be the best?

Rational people will take the bus, buying a supercar has little to do with your concept of rationality (which is basically german green party spin) and as it's not something used for daily transportation it matters little if they spend 10% fuel more than a competitor. The V10 is fun, sounds nice and may perform less but it's much more memorable, THAT'S WHAT MATTERS. Audi and VW decided to use them on their supercars, not some boring eco pretencious engine, funny thing that they have to use an italian "not green" engine unlike all their other options to have something desirable in the supercar market

This depends on whether the selling point is efficiency or power.

The selling point is the better car with more driving fun and lower environmental impact. The McLaren buyer can be proud that he is buying the best you can to protect fossil fuel reserves. The Lambo buyer just feels he needs a huge engine to serve his ego.

Stop imposing your vision and start respecting other peoples choices. The selling point of a car like a supercar, like I said, goes far from all this and, again, those cars are used once in a blue moon where small consumption differences SIMPLY DON'T MATTER. The McLaren buyer can be proud of buying what it's maybe the most boring undesirable supercar ever, to satisfy people with egos who not even a V12 would fit (like "green" people on the internet). Don't get me wrong, it's a brilliant car, but the Lambo satisfies more the expectation of a supercar and its owner might be searching for this and HE/SHE IS DOING NOTHING WRONG. Your ego in derailing an ENTIRE internet forum to green/political correctness/"cost cutting" agenda is certainly much bigger and more harmful than the lucky chap who owns a Lambo and once a month decides to drive it and that the earth is not going to die if he happens to use 2 litters more fuel than he would use with the McLaren "no one remembers it because it's boring and the McLaren F1 was better than it a century ago"

There is no doubt from the examination we have made of various cars that turbo engines easily extract more power and have the lowest fuel consumption per horse power. The NA engined cars tend to have more power to weight issues when they go to extreme power and cylinder count. The turbo cars show a little less responsiveness and have the inferior sound characteristics. The responsiveness may catch up though as soon as we see more hybrids with electric compounding like the new 2014 formula. I look forward to the impact of that technology on the super car sector. I bet it will spawn a few turbo driven super cars in short terms.

That's a HUGE misconception, used with the intention to push your agenda again. Turbo cars that go to extreme horse power will have MUCH more power to weight issues than an NA equivalent, just look what a fat piece of car is the VW Veyron. Had FIA not limited F1 cars to a ludicrous amount of cylinders, fuel flow and rpms that would be scarringly visible, as well as the extreme cost it would have

Even if restricted developing turbo engines for F1 WILL RESULT IN A SPENDING SPREE as they are not only completely different from anything used in F1 for decades but are also INFESTED with highly complex and costly green wash technology like KERS. For some one who pushes cost reduction every single opportunity and thinks life on earth depends on a bunch of rich people saving a buck on racing this is very contradictory. The cars WILL have to be entirely redone at another spending spree in which cost reduction agreements will be raped and ignored, as it is IMPOSSIBLE not to, the whole rear of ANY car using those engines will be entirely different than those used today both mechanically and aero wise than anything the teams have been doing since 20 years ago

Supercars with turbos already exist, they spend as much fuel if not more as any other supercar most times, they will not save the earth and it's not their job! The average road car will have, as always, only very small/medium input from this engine formula and certainly more resources will be spent doing it than what it might save on the race days

The turbo engine formula is interesting, will shake things up from the utter boringness and stagnation of the freeze engine/minimal budget times. May contribute to some research in fuel efficiency and is more related to current technology than the current NA V8s BUT THAT'S IT

Costs WILL be increased just like by the time they switched from V10s to V8s, IT WAS A LIE that they were going to spend less. The average car WILL NOT see significant contributions from this formula frequently, in fact a more SANE AND UNBIASED expectation will see it receiving very little input from F1 once in a while and once in a blue moon something significant will translate to the roads. F1 DOES NOT NEED to use whatever green cars are using, its a SPEED BASED COMPETITION with being as fast as possible the MAIN goal, and as their cars ARE NOT USED FOR TRANSPORTATION they have NO SINGLE OBLIGATION to be some sort of fuel efficiency and emissions pinnacle. Similar efficiency and consumption CAN BE ACHIEVED with NA engines, ESPECIALLY when you talk about engines that operate in ranges like the ones used in F1, they just don't want it any more. If worlds reserve of oil and resources were a person, he/she WOULDN'T CARE LESS about the kind of engine used in F1, the difference would be so small it would be hard to measure

Those are the facts, the rest is pure misconceptions and half lies tuned conveniently into "truth" to push YOUR sleazy agenda here. Let's talk about engines? Discuss the differences? Support F1 for trying something new finally? YES! Let's start saying lies to fit personal believes and political agendas NOT RELATED TO F1? NO! STOP PUSHING IT DOWN OTHER PEOPLES THROAT AND DERAILING THE FORUM!

[olefud]

http://autospeed.com/cms/title_Turbod-f ... ticle.html

"Implications

So let’s take a step back. In the comparison shown above of the two 2-litre engines, the turbo engine has better fuel economy, better CO2 emissions, 50 per cent more bottom-end power and 34 per cent more top-end power.

In short, it’s better in every respect (except, it must be said, cost to build)."

Granted there’s a lot of hype for turbocharging. And granted that turbocharging yields more power per unit displacement. But the thought that driving a turbocharger with normally wasted exhaust heat energy sans compounding improves efficiency is just hype. If energy doesn’t do work outside of the system, i.e. propel the vehicle, it’s not improving thermal efficiency. The energy harvested by the turbocharger is used within the system (engine), not to do measurable work –efficiency-, but instead to enhance the engine’s ability to do work -power.

With computer control of engine operating parameters it’s now possible to manage engine operating conditions to greatly optimize efficiency and power, often concurrently. For instance, it’s been mentioned in this thread that 14:1 compression ratio is being used in ICE engines. I suspect that, in order that detonation is avoided, either the VE is being limited by throttling at RPMs below the torque max, or delayed DI is being used to inject fuel only when the cylinder pressure has diminished. The higher CR allows for more efficient combustion under partial throttle, low combustion pressure conditions. This can be useful in both boosted and NA engines, but is more likely to be found in the more highly developed and sophisticated turbocharged engines. But it doesn’t mean that turbocharging is intrinsically more thermally efficient, only that all the costly efficiency driving features haven’t been applied to the more prosaic NA engines.

To match turbocharging power a NA engine will need more displacement to pump a comparable volume of air at a given RRM. However, with the same attention to engine management, the NA engine will show better efficiency with a minor weight penalty.

[pgfpro]

The NA 2.0 FSI is a joke of an engine, VW doesn't even know where to use it now a days. It's not economical, has performance way far than what was expected from it and compared to other competing engines (even non DI ones) of similar size it lacks. VW had to put a turbo on it not to be behind, it's still a not very economical engine. Honda achieved the same horse power with much less fuel consumption out of their 2 liter NA engine, which is also more reliable, the only advantage is the VWs stronger bottom end

Don't take this personally or as an attempt to deny turbo engines their advantages, I'm pointing that there are too many misconceptions on this subject and making a point for mr. WhiteBlue

OK what about Fords Ecoboost V6
http://www1.eere.energy.gov/vehiclesand ... 2011_o.pdf