joecash
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Has anyone the time to tell me the main differences between a supercharger and a turbocharger.
Kind regards
Joe
Kind regards
Joe
Difference between a supercharger and a turbocharger
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Dryce
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Supercharger is driven from engine - eg. via pully from crankshaft.
Turbocharger is driven off exhaust gasses.
Basically both are compressors but use a different mechanism to drive the compressor.
The actual compressor is different - supercharger is typically lower speed and there are several designs. A turbocharger is high speed and typically is a turbine.
I would add that using the exhaust to drive the turbocharger is typically seen as a way of drawing energy from the engine exhaust that would otherwise be wasted - whereas a supercharger is driven by the engine so consumes energy that the engine could use to move the vehicle.
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Have you googled it lol???? Supercharger is mechanically driven, turbocharger has a turbine driven off exhaust gases hence the term turbo lag
More to follow........
More to follow........
Mr Storm
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From my extremely basic knowledge of engines, a turbo charger uses the expelled exhaust gasses to force larger quantities of air into the engine which in turn creates more power, a supercharger, uses the engines own drive momentum to force more air into the engine for the same effect.
A supercharger will give increased power all across the rev range.
a turbo charger will only give extra power higher up the rev range and this is called lag.
hope this helps
A supercharger will give increased power all across the rev range.
a turbo charger will only give extra power higher up the rev range and this is called lag.
hope this helps
SavMan
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This thread should be interesting. 
Ultimately the purpose of both is to force induce air in to the combustion process.
renault12ts
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Lag is the delay in power delivery as opposed to where the power is delivered. Actually turbos tend to work at lower revs.
renault12ts
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The theory is that a turbocharger only starts working from certain engine revs and upwards - because at very low engine revs there isn't enough flow of exhaust gasses to drive the the turbine sufficiently fast to compress the intake air.
Supercharger on the other hand always works, even at low engine revs, so it has been said that the ideal engine would have both a supercharger to provide forced induction at low engine speed and a turbocharger to force-induct the engine at higher engine speeds, i.e. the two complement each other.
As for the turbo 'lag'.... there are other factors at work here. Any forced induction engine - supercharged or turbocharged - will have its compression ratio lowered to accommodate for the increased pressures in the chamber when on forced induction. This creates a particular issue for turbocharged engine, because at low rev and before the turbocharger kicks in they will be running on low compression ratio and therefore will have lower power output (when compared to a similar but naturally-aspirated engine).
This produces the feeling of a 'cammy' engine (in the olden days engines fitted with racing camshafts were rubbish at low engine speeds and only started delivering power once engine speed increased and the engine was 'on the cam') - part of the 'lag' felt with turbochargers is simply due to the fact that at lower engine speeds the engine is actually running on very low-compression until the forced induction kicks in.
This 'lag' is obviously not an issue for supercharged engined, because while they would have similar low compression ratio, the forced induction works at all times including at lower engine speeds.
Interestingly, when you look at the power output figures for the different versions of the supercharged M271 - 180K, 200K, and 230K - you can see that as the power output increases the compression ratio goes down. This is because the additional power is achieved mainly by fitting a more powerful compressor - hence the need to accommodate for the additional pressure by reducing the engine's native compression ratio.
Supercharger on the other hand always works, even at low engine revs, so it has been said that the ideal engine would have both a supercharger to provide forced induction at low engine speed and a turbocharger to force-induct the engine at higher engine speeds, i.e. the two complement each other.
As for the turbo 'lag'.... there are other factors at work here. Any forced induction engine - supercharged or turbocharged - will have its compression ratio lowered to accommodate for the increased pressures in the chamber when on forced induction. This creates a particular issue for turbocharged engine, because at low rev and before the turbocharger kicks in they will be running on low compression ratio and therefore will have lower power output (when compared to a similar but naturally-aspirated engine).
This produces the feeling of a 'cammy' engine (in the olden days engines fitted with racing camshafts were rubbish at low engine speeds and only started delivering power once engine speed increased and the engine was 'on the cam') - part of the 'lag' felt with turbochargers is simply due to the fact that at lower engine speeds the engine is actually running on very low-compression until the forced induction kicks in.
This 'lag' is obviously not an issue for supercharged engined, because while they would have similar low compression ratio, the forced induction works at all times including at lower engine speeds.
Interestingly, when you look at the power output figures for the different versions of the supercharged M271 - 180K, 200K, and 230K - you can see that as the power output increases the compression ratio goes down. This is because the additional power is achieved mainly by fitting a more powerful compressor - hence the need to accommodate for the additional pressure by reducing the engine's native compression ratio.
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SavMan
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Lag is typical referred to as the time taken at full WOT for the turbo to come onto boost.
The time for boost is affected by both the airflow and the load, a turbo engine will typically see a greater variation to boost at a particular rpm due to load than a supercharged engines which is more progressive.
As an example test a supercharged engine in neutral and you will still see some boost but turbo's typically show zero.
As for low, mid or high RPM that really depends on the design of the turbo vs the application.
The time for boost is affected by both the airflow and the load, a turbo engine will typically see a greater variation to boost at a particular rpm due to load than a supercharged engines which is more progressive.
As an example test a supercharged engine in neutral and you will still see some boost but turbo's typically show zero.
As for low, mid or high RPM that really depends on the design of the turbo vs the application.
renault12ts
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I was just thinking the same about you.
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A supercharger whines and sounds great.
A turbocharger whistles and only sounds good.
That is all anyone really needs to know
A turbocharger whistles and only sounds good.
That is all anyone really needs to know
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This thread could run and run as the topic of forced induction is immensely deep. I learnt a lot running a couple of turbo charged Hayabusas in the early days '99-'03 and a friend who went the Supercharging route.
There is a LOT to know and it's all very technical, especially when bolting them to all alloy high revving motorcycle engines.
There is a LOT to know and it's all very technical, especially when bolting them to all alloy high revving motorcycle engines.
grober
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HowStuffWorks "What is the difference between a turbocharger and a supercharger on a car\'s engine?".
Virtually all small capacity car/van Mercedes diesels are turbocharged now. [ sometimes one turbo quite often 2 now]. Mercedes had a spell using superchargers on their petrol cars ---they called them "Kompressors" They have switched to turbo charging their petrols due to the greater inherent thermal efficiency- they are using that waste heat energy that would normally simply go out the exhaust.
Virtually all small capacity car/van Mercedes diesels are turbocharged now. [ sometimes one turbo quite often 2 now]. Mercedes had a spell using superchargers on their petrol cars ---they called them "Kompressors" They have switched to turbo charging their petrols due to the greater inherent thermal efficiency- they are using that waste heat energy that would normally simply go out the exhaust.
blue gnome123
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Actually electronically driven (at low revs) turbochargers are in development and probably offer the best of both worlds. I believe that we'll see a lot more in the next few years. These start working at idle.
If you want forced induction at low rpm then it has to be supercharged
If you want a ruddy great burst of power delivery with some lag then go for a turbo charged engine. IMHO the M113k is an incredible engine. The supercharged effect on that lump is so smooth and delivered perfectly
Then take a turbo'd V12 and again the performance is mind boggling. So much low down torque that the lag from the turbos is almost hard to distinguish
But I would take an sc over a turbo anyday!
Unless it was a straight six then turbos all the way
If you want a ruddy great burst of power delivery with some lag then go for a turbo charged engine. IMHO the M113k is an incredible engine. The supercharged effect on that lump is so smooth and delivered perfectly
Then take a turbo'd V12 and again the performance is mind boggling. So much low down torque that the lag from the turbos is almost hard to distinguish
But I would take an sc over a turbo anyday!
Unless it was a straight six then turbos all the way
Or have the best of both worlds with a twincharger!
