Does prolonged turbo boost = damage?
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If the engine is built with boost in mind and is correspondingly strong enough internally for the power it produces, as long as there's adequate cooling for everything, running at full power shouldn't be any worse than running an NA engine at WOT for sustained periods.
The only difference is instead of running the E10 87 octane swill over here, you would probably get 93 or higher octane with no alcohol in it...the ECU in that little boosted motor would love that at high temps.
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Thank you all for your responses! This is a purely hypothetical scenario, as much as I'd like to be able to make it happen.
We always hear about how hot turbos get, people talk about seeing them glowing cherry red. I guess I'd gotten the impression that prolonged use would be harmful. I'm glad to hear that they do hold up well during extended periods of boost.
@IndyIan - The ST has what Ford calls an overboost feature. It's supposed to give more power for 15 seconds, then the turbo is dialed back somewhat. I don't know how this engine's maximum output compares to that of a standard 2.0 Ecoboost found in one of Ford's other cars.
@glock19 - Without getting into any specifics, I've found that this car is quite comfortable in triple digits.
We always hear about how hot turbos get, people talk about seeing them glowing cherry red. I guess I'd gotten the impression that prolonged use would be harmful. I'm glad to hear that they do hold up well during extended periods of boost.
@IndyIan - The ST has what Ford calls an overboost feature. It's supposed to give more power for 15 seconds, then the turbo is dialed back somewhat. I don't know how this engine's maximum output compares to that of a standard 2.0 Ecoboost found in one of Ford's other cars.
@glock19 - Without getting into any specifics, I've found that this car is quite comfortable in triple digits.
Originally Posted By: raytseng
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
In America it is hard to find anyplace where you can run full throttle for very long at all, even on a track.
90hp econobox? Maybe. 180 mph car? Not going to happen.
Modern engine controls have made turbos quite good, but they will always be a more complex way to make hp. A true engineer knows why complex is not always a good thing. This only matters to the long term owner, not the two year lease guy.
90hp econobox? Maybe. 180 mph car? Not going to happen.
Modern engine controls have made turbos quite good, but they will always be a more complex way to make hp. A true engineer knows why complex is not always a good thing. This only matters to the long term owner, not the two year lease guy.
Originally Posted By: sciphi
Originally Posted By: raytseng
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
Wow, do you mean 1 hour of track time or just 1 hour at full throttle? The Neon took about 2-2.5 hours to empty its tank on a track, so maybe 60-70% WO with sort of similar HP.
I started running out in the corners but I had enough to go 5 miles down the road to fill up.
Originally Posted By: raytseng
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
Wow, do you mean 1 hour of track time or just 1 hour at full throttle? The Neon took about 2-2.5 hours to empty its tank on a track, so maybe 60-70% WO with sort of similar HP.
I started running out in the corners but I had enough to go 5 miles down the road to fill up.
Originally Posted By: IndyIan
Originally Posted By: sciphi
Originally Posted By: raytseng
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
Wow, do you mean 1 hour of track time or just 1 hour at full throttle? The Neon took about 2-2.5 hours to empty its tank on a track, so maybe 60-70% WO with sort of similar HP.
I started running out in the corners but I had enough to go 5 miles down the road to fill up.
1 hour of WOT operation. It consumes 12 gph at WOT. On a track, it would likely get a few hours thanks to getting about 18 mpg in track use. Ran it around Watkins Glen for a few laps, and got that for fuel economy.
Originally Posted By: sciphi
Originally Posted By: raytseng
At that speed, you'd probably be out of gas before you hit the hour mark.
So it's just all hypothetical. Something to think about
That's the truth. At full boogie my Cruze will empty its 12-gallon (Eco manual model specific, others have a 15 gallon tank) in under an hour.
Folks have had small engines at full boost for long periods of time. With modern water-cooled turbos and modern oils, it will be fine with even 5 minutes of normal, off-boost driving to cool down.
Wow, do you mean 1 hour of track time or just 1 hour at full throttle? The Neon took about 2-2.5 hours to empty its tank on a track, so maybe 60-70% WO with sort of similar HP.
I started running out in the corners but I had enough to go 5 miles down the road to fill up.
1 hour of WOT operation. It consumes 12 gph at WOT. On a track, it would likely get a few hours thanks to getting about 18 mpg in track use. Ran it around Watkins Glen for a few laps, and got that for fuel economy.
Originally Posted By: IndyIan
Originally Posted By: Palut
How well does a turbo engine stand up to prolonged boost?
I've got a Focus ST with the 2.0 Ecoboost. Ford says that its top speed is a drag limited 154 mph. Let's say that I shipped it to Germany and drove at 140-150 mph on the autobahn for an hour. That would have me in top gear, at high revs, and at or close to full boost for a full hour. How would the turbo hold up? Can a turbo be kept from overheating over a long period like that?
Doesn't the ST have a limited amount of time at full boost? So Ford is protecting some part of the engine from over heating. First time I've heard of this in a production car, but I'm sure that the lower level boost is fine for long periods of time.
Focii ST's have a oddly called "Overboost" feature, Which isn't really overboost.
It will hold the Turbo at it's Full 20-25ish psi boost for 15 FULL SECONDS!
Originally Posted By: Palut
How well does a turbo engine stand up to prolonged boost?
I've got a Focus ST with the 2.0 Ecoboost. Ford says that its top speed is a drag limited 154 mph. Let's say that I shipped it to Germany and drove at 140-150 mph on the autobahn for an hour. That would have me in top gear, at high revs, and at or close to full boost for a full hour. How would the turbo hold up? Can a turbo be kept from overheating over a long period like that?
Doesn't the ST have a limited amount of time at full boost? So Ford is protecting some part of the engine from over heating. First time I've heard of this in a production car, but I'm sure that the lower level boost is fine for long periods of time.
Focii ST's have a oddly called "Overboost" feature, Which isn't really overboost.
It will hold the Turbo at it's Full 20-25ish psi boost for 15 FULL SECONDS!
Originally Posted By: michaelluscher
Originally Posted By: IndyIan
Originally Posted By: Palut
How well does a turbo engine stand up to prolonged boost?
I've got a Focus ST with the 2.0 Ecoboost. Ford says that its top speed is a drag limited 154 mph. Let's say that I shipped it to Germany and drove at 140-150 mph on the autobahn for an hour. That would have me in top gear, at high revs, and at or close to full boost for a full hour. How would the turbo hold up? Can a turbo be kept from overheating over a long period like that?
Doesn't the ST have a limited amount of time at full boost? So Ford is protecting some part of the engine from over heating. First time I've heard of this in a production car, but I'm sure that the lower level boost is fine for long periods of time.
Focii ST's have a oddly called "Overboost" feature, Which isn't really overboost.
It will hold the Turbo at it's Full 20-25ish psi boost for 15 FULL SECONDS!
Yes, now the Blue Oval just has to find a way to get drive to those back wheels as well.
Originally Posted By: IndyIan
Originally Posted By: Palut
How well does a turbo engine stand up to prolonged boost?
I've got a Focus ST with the 2.0 Ecoboost. Ford says that its top speed is a drag limited 154 mph. Let's say that I shipped it to Germany and drove at 140-150 mph on the autobahn for an hour. That would have me in top gear, at high revs, and at or close to full boost for a full hour. How would the turbo hold up? Can a turbo be kept from overheating over a long period like that?
Doesn't the ST have a limited amount of time at full boost? So Ford is protecting some part of the engine from over heating. First time I've heard of this in a production car, but I'm sure that the lower level boost is fine for long periods of time.
Focii ST's have a oddly called "Overboost" feature, Which isn't really overboost.
It will hold the Turbo at it's Full 20-25ish psi boost for 15 FULL SECONDS!
Yes, now the Blue Oval just has to find a way to get drive to those back wheels as well.
Ask a train engineer, truck driver, or boat captain. Turbo engines are built for boost and rely on it for hours of constant operation. Think a tug boat or train is ever not making boost?
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True, but t hose are engineered to much higher standards than consumer vehicles.
My boss is scared of boost due to his experience with older vehicles that had them. Apparently, they used an older style bearing (forget if it was sleeve or ball bearing) and was cooled by oil. He used to have to wait at least 5 minutes of idling the car before shutting it down so that the turbo can cool down slowly after a long trip. Otherwise, shutting the car off after a long drive increased the chance of the turbo cracking. Of course, this is what I've been told about old turbo setups.
It is my understanding that newer turbos use better bearing technology, etc.
I just hope you are using good quality oil, oil cooler and transmission cooler if you plan on driving at such long extended periods of time at high RPM and high speed.
My boss is scared of boost due to his experience with older vehicles that had them. Apparently, they used an older style bearing (forget if it was sleeve or ball bearing) and was cooled by oil. He used to have to wait at least 5 minutes of idling the car before shutting it down so that the turbo can cool down slowly after a long trip. Otherwise, shutting the car off after a long drive increased the chance of the turbo cracking. Of course, this is what I've been told about old turbo setups.
It is my understanding that newer turbos use better bearing technology, etc.
I just hope you are using good quality oil, oil cooler and transmission cooler if you plan on driving at such long extended periods of time at high RPM and high speed.
Originally Posted By: accent2012
True, but t hose are engineered to much higher standards than consumer vehicles.
My boss is scared of boost due to his experience with older vehicles that had them. Apparently, they used an older style bearing (forget if it was sleeve or ball bearing) and was cooled by oil. He used to have to wait at least 5 minutes of idling the car before shutting it down so that the turbo can cool down slowly after a long trip. Otherwise, shutting the car off after a long drive increased the chance of the turbo cracking. Of course, this is what I've been told about old turbo setups.
It is my understanding that newer turbos use better bearing technology, etc.
I just hope you are using good quality oil, oil cooler and transmission cooler if you plan on driving at such long extended periods of time at high RPM and high speed.
The issue with those older turbos was that they were exclusively cooled by oil and also sleeve bearings instead of ball bearings (although ball bearings can have issues too). The turbo bearings themselves aren't that tough on the motor oil. The oil is called upon to remove heat from the bearings, and still does in a modern water cooled turbo, but the water cooling helps a lot. Here's my layman's explanation of the issue.....
The issue used to be that there was:
1) Kinetic energy stored in a spinning turbo.
2) Heat from the exhaust making the turbo housing really hot. They will in fact glow red.
3) Reliance on the oil to carry away heat.
So if you had just driven your vehicle on high boost and wanted to shut it down immediately, there's a lot of energy in there. You just shut down the engine and the flow of oil from the oil pump. The turbo is still spinning and creating heat. The turbo housing is glowing red and still transferring heat to the bearings. So with the combination of all that, the turbo bearings are now overheating and the oil is remaining there soaking in all that heat at a temperature well past its specified limits. It's gradually "coking" - or forming carbon deposits from the oil. Here's a photo I found of a trashed sleeve bearing:
http://www.autospeed.com/cms/A_111628/article.html
This article claims that because of ball bearing design, there's actually less cooling from the oil, and water cooling is almost a requirement.
So back to the old oil cooled turbos - they would generally last longer if the turbo was allowed to reduce speed (and thus stored energy) and the housing was allowed to cool before the flow of oil was shut off. Some people would wait a minute or two before shutting off their engines. Others set up timer systems that shut off the engine after idling for a designated time.
Supposedly modern turbos with ball bearings and water cooling don't have these limitations as much. The bearings themselves don't create as much heat from friction as the sleeve bearings and the cooling system is designed to carry away heat by allowing coolant to vaporize and settle in a high coolant tank. And it will constantly draw in cooler water to do this without any pump operating.
True, but t hose are engineered to much higher standards than consumer vehicles.
My boss is scared of boost due to his experience with older vehicles that had them. Apparently, they used an older style bearing (forget if it was sleeve or ball bearing) and was cooled by oil. He used to have to wait at least 5 minutes of idling the car before shutting it down so that the turbo can cool down slowly after a long trip. Otherwise, shutting the car off after a long drive increased the chance of the turbo cracking. Of course, this is what I've been told about old turbo setups.
It is my understanding that newer turbos use better bearing technology, etc.
I just hope you are using good quality oil, oil cooler and transmission cooler if you plan on driving at such long extended periods of time at high RPM and high speed.
The issue with those older turbos was that they were exclusively cooled by oil and also sleeve bearings instead of ball bearings (although ball bearings can have issues too). The turbo bearings themselves aren't that tough on the motor oil. The oil is called upon to remove heat from the bearings, and still does in a modern water cooled turbo, but the water cooling helps a lot. Here's my layman's explanation of the issue.....
The issue used to be that there was:
1) Kinetic energy stored in a spinning turbo.
2) Heat from the exhaust making the turbo housing really hot. They will in fact glow red.
3) Reliance on the oil to carry away heat.
So if you had just driven your vehicle on high boost and wanted to shut it down immediately, there's a lot of energy in there. You just shut down the engine and the flow of oil from the oil pump. The turbo is still spinning and creating heat. The turbo housing is glowing red and still transferring heat to the bearings. So with the combination of all that, the turbo bearings are now overheating and the oil is remaining there soaking in all that heat at a temperature well past its specified limits. It's gradually "coking" - or forming carbon deposits from the oil. Here's a photo I found of a trashed sleeve bearing:
http://www.autospeed.com/cms/A_111628/article.html
This article claims that because of ball bearing design, there's actually less cooling from the oil, and water cooling is almost a requirement.
So back to the old oil cooled turbos - they would generally last longer if the turbo was allowed to reduce speed (and thus stored energy) and the housing was allowed to cool before the flow of oil was shut off. Some people would wait a minute or two before shutting off their engines. Others set up timer systems that shut off the engine after idling for a designated time.
Supposedly modern turbos with ball bearings and water cooling don't have these limitations as much. The bearings themselves don't create as much heat from friction as the sleeve bearings and the cooling system is designed to carry away heat by allowing coolant to vaporize and settle in a high coolant tank. And it will constantly draw in cooler water to do this without any pump operating.
Forgive me, but I couldn't resist: http://www.youtube.com/watch?v=arL04K3HLMw
In my Audi specifically, it probably can go down the Autobahn at full tilt until its gas tank is empty and be perfectly happy, and that's with two turbos.
It has a secondary water pump with a thermo switch that pumps coolant directly into and through the turbos to keep them from getting too hot that they would be damaged. In the 5+ years that I've owned it, the secondary water pump has never kicked on and that includes a run up state highway 41 in Upper Michigan from Gladstone to Marquette with my foot on the floor. 50 miles at WOT a good portion of the time. Speed limiter was verified to be 137 mph.
It has a secondary water pump with a thermo switch that pumps coolant directly into and through the turbos to keep them from getting too hot that they would be damaged. In the 5+ years that I've owned it, the secondary water pump has never kicked on and that includes a run up state highway 41 in Upper Michigan from Gladstone to Marquette with my foot on the floor. 50 miles at WOT a good portion of the time. Speed limiter was verified to be 137 mph.
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