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Anything similar for petrol engines?
 

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I'd assume this is a tacked on version of their triplecharged concept. Same idea--electrically drive the turbo at low RPM... This just does with with minimal R&D... Take the XC90 air suspension compressor and tank. Add a hose and a solenoid and viola.
 

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Effectively an electric supercharger. But I wonder why they don't feed the compressed air straight into the intake manifold?
Not an electric supercharger. That would have a motor acting on the compression turbine. Also, pushing air into the intake wouldn't do anything. It'd have to make its way through the engine which would negate any effect. The idea is to spin the same turbine that the exhaust turns before their is sufficient exhaust velocity and volume to do so.
 

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I'd assume this is a tacked on version of their triplecharged concept. Same idea--electrically drive the turbo at low RPM... This just does with with minimal R&D... Take the XC90 air suspension compressor and tank. Add a hose and a solenoid and viola.
The neat thing about this method is that you are driving the same turbine that the exhaust does. So the turbine , and the whole turbocharger, remains very simple.
 

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Not an electric supercharger. That would have a motor acting on the compression turbine. Also, pushing air into the intake wouldn't do anything. It'd have to make its way through the engine which would negate any effect. The idea is to spin the same turbine that the exhaust turns before their is sufficient exhaust velocity and volume to do so.
An electric supercharger is “an electrically driven compressor”. And “pushing air into the intake” is what all other superchargers and turbochargers do.
 

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One reason for the accumulator is probably to give a mild hybrid effect by driving the electric compressor only on the overrun, braking or certain part-load situations, like a “smart” alternator, or a micro version of the compressed-air hybrid system used by Peugeot-Citroen.
 

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Effectively an electric supercharger. But I wonder why they don't feed the compressed air straight into the intake manifold?
It's more effective to quickly spool the turbo since it's probably getting somewhere near twice the atmospheric pressure inside the engine that way.
 

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Wish my Fiat 500 Abarth had this system. God knows it has turbo lag!!!

Pic related/off topic.
 

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I don't see any advantage in compressing air with an electric compressor and then using that compressed air to help a turbocharger compress different air and only THEN feed THAT compressed air into the intake. It all seems very indirect.

But no doubt Volvo have some method in their seeming madness, possibly related to EGR. Exhaust Gas Recirculation is increasing in modern diesel and affects turbocharging in peculiar ways.
 

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I don't see any advantage in compressing air with an electric compressor and then using that compressed air to help a turbocharger compress different air and only THEN feed THAT compressed air into the intake. It all seems very indirect.

But no doubt Volvo have some method in their seeming madness, possibly related to EGR. Exhaust Gas Recirculation is increasing in modern diesel and affects turbocharging in peculiar ways.
Because it requires less air volume to spin a turbine wheel faster while exhaust volume builds than to shove air into the intake stream... Also that air would need to be metered... which adds more complexity. Injecting a turbine with air to spin it faster is A) how jet engines start, B) how turbo lag is removed in certain turbo setups. I could do what Volvo is doing right now with an air-tank, valve, hose, and fitting tapped into the exhaust manifold... Wouldn't be elegant but it would work.
 

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The neat thing about this method is that you are driving the same turbine that the exhaust does. So the turbine , and the whole turbocharger, remains very simple.
I wonder if this isn't an unexpected bonus of having only the 4-cylinder engine option (and variants thereof). Makes the drivetrain engineers have no choice but to focus on improving and building out that particular engine.
 

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Because it requires less air volume to spin a turbine wheel faster while exhaust volume builds than to shove air into the intake stream... Also that air would need to be metered... which adds more complexity. Injecting a turbine with air to spin it faster is A) how jet engines start, B) how turbo lag is removed in certain turbo setups. I could do what Volvo is doing right now with an air-tank, valve, hose, and fitting tapped into the exhaust manifold... Wouldn't be elegant but it would work.
Agreed. It's easier to keep a spinning turbo spinning than to spool it up. Remove the spool up, and turbocharger effect is instantaneous.

Does anybody worry about the longevity or reliability of these systems, though? These cars could take huge hits in resale value once they are out of warranty.
 

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Agreed. It's easier to keep a spinning turbo spinning than to spool it up. Remove the spool up, and turbocharger effect is instantaneous.

Does anybody worry about the longevity or reliability of these systems, though? These cars could take huge hits in resale value once they are out of warranty.
Look at air suspension systems. Assume the pump will fail at some point... So I'd assume 500-1000 every 150k... At least.
 

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Agreed. It's easier to keep a spinning turbo spinning than to spool it up. Remove the spool up, and turbocharger effect is instantaneous.

Does anybody worry about the longevity or reliability of these systems, though? These cars could take huge hits in resale value once they are out of warranty.
Ha! The germans seem to do just fine with their resale value! :D
 

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An electric supercharger is “an electrically driven compressor".]/QUOTE]

Yes, I get that. I do not understand why you would call this "Effectively an electric supercharger". It's not in the slightest.

I misunderstood your point about introducing the air into the manifold. I thought you were saying to do that to spool the turbo. The reason you can't use the compressed air tank to feed the intake is a volume issue. That compressor and tank can't keep up with the necessary demand from the engine, as others have said. It's simply an effective way to overcome the inertia of the turbo before there is a lot of exhaust volume.
 

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Because it requires less air volume to spin a turbine wheel faster while exhaust volume builds than to shove air into the intake stream... Also that air would need to be metered... which adds more complexity. Injecting a turbine with air to spin it faster is A) how jet engines start, B) how turbo lag is removed in certain turbo setups. I could do what Volvo is doing right now with an air-tank, valve, hose, and fitting tapped into the exhaust manifold... Wouldn't be elegant but it would work.
You're missing my point. And you could NOT do what Volvo are doing the way you say. In particular, you would need the electric compressor Volvo use.
 

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An electric supercharger is “an electrically driven compressor".]/QUOTE]

Yes, I get that. I do not understand why you would call this "Effectively an electric supercharger". It's not in the slightest.

I misunderstood your point about introducing the air into the manifold. I thought you were saying to do that to spool the turbo. The reason you can't use the compressed air tank to feed the intake is a volume issue. That compressor and tank can't keep up with the necessary demand from the engine, as others have said. It's simply an effective way to overcome the inertia of the turbo before there is a lot of exhaust volume.
See my reply above. Most electric superchargers work directly by pumping air into the intakes. This one works indirectly by intermittently pumping air into an accumulator, which dispenses into the exhaust, which spins the turbocharger quicker, which pumps more air into the intakes, exactly the same effect but with two extra steps added, for reasons I've suggested further above.

Air volume and demand is not an issue since Volvo's new system does not and cannot work continuously.
 
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