Are turbo engines more efficient when driven hard?
07-24-2015, 10:06 PM
#31
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07-24-2015, 10:25 PM
#32
Race Director
Are turbo engines more efficient when driven hard?
Originally Posted by cloud9blue
Ok, so what are you trying to say exactly?
That particular article skips a lot of technical details just FYI.
Now remember the turbines are powered by the exhaust flow, and the only way to notice any significant lags in these turbo setups, which typically uses an undersize turbine/compressor combo to drastically minimize the spool up time, is by flooring the engine at very low rpm range from 1500-2000rpms, considering the engine is producing a lot of exhaust gas volume to spin up the turbines to the full boost. You are really not losing much, because if you do the same in a high revving NA engine like the flat 6 in these cars, you won't get much tq/hp out of them at that rpm range anyway. At higher rpms, with the correct fueling and wastegate mapping of the turbos, lag should be virtually unnoticeable for these engines (these are not some heavily boosted inline-4 with tiny 1.4-2.0 L displacement after all...)
Seriously, I am a little tired of these "turbo bashing" that's going on these days on the forums. Turbos are the best technical solution we have at the moment to meet the emission standard, which honestly should be there to push the manufacturers to develop cleaner technology so our cities don't end up covered in smog like 1950s London or Beijing is like these days.
If you like NA engines that's fine, but these blind hate toward new technology is just silly. Go take a extended test drive on a modern turbocharged sports car, or better yet, take one to the track, turn off the stability and traction control, explore its limit if your driving skills are up to the challenge. And then let us know if you still think turbo engines are craps...
That particular article skips a lot of technical details just FYI.
Now remember the turbines are powered by the exhaust flow, and the only way to notice any significant lags in these turbo setups, which typically uses an undersize turbine/compressor combo to drastically minimize the spool up time, is by flooring the engine at very low rpm range from 1500-2000rpms, considering the engine is producing a lot of exhaust gas volume to spin up the turbines to the full boost. You are really not losing much, because if you do the same in a high revving NA engine like the flat 6 in these cars, you won't get much tq/hp out of them at that rpm range anyway. At higher rpms, with the correct fueling and wastegate mapping of the turbos, lag should be virtually unnoticeable for these engines (these are not some heavily boosted inline-4 with tiny 1.4-2.0 L displacement after all...)
Seriously, I am a little tired of these "turbo bashing" that's going on these days on the forums. Turbos are the best technical solution we have at the moment to meet the emission standard, which honestly should be there to push the manufacturers to develop cleaner technology so our cities don't end up covered in smog like 1950s London or Beijing is like these days.
If you like NA engines that's fine, but these blind hate toward new technology is just silly. Go take a extended test drive on a modern turbocharged sports car, or better yet, take one to the track, turn off the stability and traction control, explore its limit if your driving skills are up to the challenge. And then let us know if you still think turbo engines are craps...
What "used" 991's are you looking to buy? Confused? One of the NA ones, or looking to buy a used 991.2 that hasn't even been released?
If your concern is the "smog infested" cities you claim, isn't a Toyota Pruis more up your alley?
My beef is the fact that people are trying to argue that Porsche, Ferrari, etc would be going turbo regardless as a superior engine, as opposed to being FORCED to meet strict gov't regulations.
Liking or not liking turbo engines is a choice. I can accept that.
Myself having less options of cars to purchase in the future based on my engine preference because of the Al Gore's of the world think they know better doesn't sit well with me.
Last edited by STG; 07-24-2015 at 10:46 PM.
07-24-2015, 10:33 PM
#33
RL Community Team
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Rennlist Member
I'm convinced.
Forced Induction must suck.
I will happily take anyone's GT2 off their hands. Gratis.
Forced Induction must suck.
I will happily take anyone's GT2 off their hands. Gratis.
07-24-2015, 10:48 PM
#34
Rennlist Member
Take the time to read. A very good article ...
"WE DON'T LIKE THE TURBO," SAID THE MAN WITH THE ITALIAN ACCENT
I'd like to hear any debate from anything in the article!
http://www.roadandtrack.com/car-cult...turbocharging/
"WE DON'T LIKE THE TURBO," SAID THE MAN WITH THE ITALIAN ACCENT
I'd like to hear any debate from anything in the article!
http://www.roadandtrack.com/car-cult...turbocharging/
Turbo engines are "craps" as you say. If I liked them, I'd already own one.
What "used" 991's are you looking to buy? Confused? One of the NA ones, or looking to buy a used 991.2 that hasn't even been released?
If your concern is the "smog infested" cities you claim, isn't a Toyota Pruis more up your alley?
My beef is the fact that people are trying to argue that Porsche, Ferrari, etc would be going turbo regardless as a superior engine, as opposed to being FORCED to meet strict gov't regulations.
Liking or not liking turbo engines is a choice. I can accept that.
Myself having less options of cars to purchase in the future based on my engine preference because of the Al Gore's of the world think they know better doesn't sit well with me.
What "used" 991's are you looking to buy? Confused? One of the NA ones, or looking to buy a used 991.2 that hasn't even been released?
If your concern is the "smog infested" cities you claim, isn't a Toyota Pruis more up your alley?
My beef is the fact that people are trying to argue that Porsche, Ferrari, etc would be going turbo regardless as a superior engine, as opposed to being FORCED to meet strict gov't regulations.
Liking or not liking turbo engines is a choice. I can accept that.
Myself having less options of cars to purchase in the future based on my engine preference because of the Al Gore's of the world think they know better doesn't sit well with me.
Anyway, I don't see the point of continuing this discussion with you given that you think anyone who has a realistic understanding of the environmental problems we must all be a tree hugging, Al-Gore loving, Prius driving liberal. But you are free to educate yourself on the power delivery difference between NA and a moderately boosted turbocharged car. Peak hp isn't everything just remember. I also don't understand how you end up with less options of cars to purchase in the future. If you care about screaming high rev engines and absolutely purest of engine sounds, why not just get a GT3? They aren't that much more expensive than a well optioned C2S or GTS to begin.
Unlike some on here, I very much like what I see from the leaked information so far. Most likely will just pick up a new one a year or two down the line once I make sure there isn't any glaring issue with them in the first model year. Just not a fan buying first year models, since they are more problem prone than most from my experience, particularly with the German manufacturers.
07-24-2015, 11:00 PM
#35
Regardless of what anyone thinks about CO2, efficiency, technology, corporate profits, the planet- or literally anything else at all- the fact is this is just another example of individual liberty being trampled by tyranny. This is the mindset that regulates the acceptable curvature of BANANAS! https://en.wikipedia.org/wiki/Commis...C)_No._2257/94
I saw three early 911's on my way home today. Owning and driving one for so long you kind of forget how radically different they are, but it really stands out when you see one in traffic. I mean those things sit LOW! The front (and rear!) bumpers are mid-shin level. But look how high the 991 sits. That's not technology, that's regulations.
It just goes on and on. I mean, BANANAS!
What I said the last time this came up goes double today. Porsche knows very well how to make a great turbo engine, and they know better than anyone where and when and how to make a great car with a turbo. See: Turbo, GT2, etc. Which is what Porsche (and everyone else) should be left free to continue doing. You definitely picked the right issue to have a beef with!
07-25-2015, 01:34 PM
#36
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So we should put lead back in gas should we? I mean, it's better for car engines and older cars had to spent a lot of money to get converted to unleaded... Governments should stay out of my gas choice!
Seriously, progress means change. Do we loose some things with change, sure.
Personally I miss 2 valve engines, they had better low end torque and didn't require a gillilion rpms to make some BS maximum HP marketing rating....
Seriously, progress means change. Do we loose some things with change, sure.
Personally I miss 2 valve engines, they had better low end torque and didn't require a gillilion rpms to make some BS maximum HP marketing rating....
07-25-2015, 01:45 PM
#37
Race Car
I saw them race up close (corner working at Daytona, Watkins and Mid-Ohio). The 935s were drugs! They were essentially dragsters with huge brakes and so much rubber the track twisted when they went by.
07-25-2015, 01:47 PM
#38
Seriously, I am a little tired of these "turbo bashing" that's going on these days on the forums. Turbos are the best technical solution we have at the moment to meet the emission standard, which honestly should be there to push the manufacturers to develop cleaner technology so our cities don't end up covered in smog like 1950s London or Beijing is like these days.
If you like NA engines that's fine, but these blind hate toward new technology is just silly. Go take a extended test drive on a modern turbocharged sports car, or better yet, take one to the track, turn off the stability and traction control, explore its limit if your driving skills are up to the challenge. And then let us know if you still think turbo engines are craps...
If you like NA engines that's fine, but these blind hate toward new technology is just silly. Go take a extended test drive on a modern turbocharged sports car, or better yet, take one to the track, turn off the stability and traction control, explore its limit if your driving skills are up to the challenge. And then let us know if you still think turbo engines are craps...
Other than that, you might want to take a laxative before you hit reply the next time. People are merely discussing the issue and, yes, there are those of us that would rather not have forced induction. I've owned both supercharged and turbocharged cars and didn't care for either really. For sure, the new ones are better, but there is still going to be a bit of lag there and the 'unique' noise many of us don't care for.
The undeniable fact is that the proliferation of turbos is entirely a government forced mandate, the necessity of which is an entirely different debate.
07-25-2015, 01:50 PM
#39
That's what you think his logical extension would be? Do you argue against the manual transmission crowd by saying 'so we should put manual spark advance back in the car should we?'
There are logical lines and illogical lines. Drawing one and not the other is not a contradiction.
There are logical lines and illogical lines. Drawing one and not the other is not a contradiction.
07-25-2015, 01:54 PM
#40
BTW, though I'll never own one, I love the idea of more fuel efficient turbo cars and EVs like the Teslas, the i3s, the Leaf, the Prius and any other little clown car the manufacturers want to build. They're awesome, because they improve the environment (a teeny bit) and they use less fuel, which means lower demand for petrol, which means cheaper gas for the rest of us and more years of supply. It's a win-win.
07-25-2015, 05:50 PM
#41
Burning Brakes
Are turbo engines more efficient when driven hard?
Do they really use less fuel though? The point people are trying to make, which is getting drowned out in the cacophony of "save the planet and it's puppies" is that the efficiency ratings for these particular turbos is fake. They appear more efficient on paper but in the real world are often LESS efficient. Therefore more puppies will die from a lack of social justice.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
07-25-2015, 05:52 PM
#42
Do they really use less fuel though? The point people are trying to make, which is getting drowned out in the cacophony of "save the planet and it's puppies" is that the efficiency ratings for these particular turbos is fake. They appear more efficient on paper but in the real world are often LESS efficient. Therefore more puppies will die from a lack of social justice.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
07-25-2015, 06:01 PM
#43
Rennlist Member
Do they really use less fuel though? The point people are trying to make, which is getting drowned out in the cacophony of "save the planet and it's puppies" is that the efficiency ratings for these particular turbos is fake. They appear more efficient on paper but in the real world are often LESS efficient. Therefore more puppies will die from a lack of social justice.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
However, it has to be noted that at max. power and high rpm, the fuel saving is less significant comparing to modern DFI NA engine like the 991.1 (which I am sure that Porsche optimized the cam and ign timing for high rpm power delivery), as you can only extract a set amount of energy from a given amount of fuel. But these are street cars after all, and since you are not spending 80% of the time at full throttle, the fuel saving (and the extra power at mid range) will be quite noticeable.
Yes, I bet people like us care very little about the fuel efficiency (my current car, with all the changes I made to it, only does 12mpg while running on E85, but it makes it up by making around 440whp). But if the turbo technology allows for better performance and allows Porsche to meet the more stringent emission regulation (whether these regulations are justified or not is another debate entirely), why all the hate?
07-25-2015, 06:03 PM
#44
They do, at least during normal driving. Direct injection is incredibly efficient as it allows for much leaner AFR than conventional port injection without running the risk of pre-detonation, and coupled with turbocharging, you can run even leaner AFR (hence less fuel) at low to mid power output.
However, it has to be noted that at max. power and high rpm, the fuel saving is less significant comparing to modern DFI NA engine like the 991.1 (which I am sure that Porsche optimized the cam and ign timing for high rpm power delivery), as you can only extract a set amount of energy from a given amount of fuel. But these are street cars after all, and since you are not spending 80% of the time at full throttle, the fuel saving (and the extra power at mid range) will be quite noticeable.
However, it has to be noted that at max. power and high rpm, the fuel saving is less significant comparing to modern DFI NA engine like the 991.1 (which I am sure that Porsche optimized the cam and ign timing for high rpm power delivery), as you can only extract a set amount of energy from a given amount of fuel. But these are street cars after all, and since you are not spending 80% of the time at full throttle, the fuel saving (and the extra power at mid range) will be quite noticeable.
07-25-2015, 06:10 PM
#45
Do they really use less fuel though? The point people are trying to make, which is getting drowned out in the cacophony of "save the planet and it's puppies" is that the efficiency ratings for these particular turbos is fake. They appear more efficient on paper but in the real world are often LESS efficient. Therefore more puppies will die from a lack of social justice.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
These numbers are fake and unrealistic. That's the point people are trying to bring up and that's what we should be discussing.
FWIW, I have not heard of a modern turbo engine that is less efficient in the real world than an NA engine with the same output, driven the same way. Maybe if you are pedal to the metal *all* the time - although even then a well-designed turbo engine should be in the same ballpark, and much more efficient when you're cruising on the highway. And it turns out most spend less time accelerating sharply than you do maintaining speed.
(FWIW, this applies to supercharges too - any kind of well designed forced induction is, IRL, more efficient than a larger displacement NA).