We see a lot of cars today coming up with turbocharged engines and that is there for a reason. But the biggest thing in the modern two wheeler industry was the first production bike ever built with a supercharger. It is the Kawasaki Ninja H2. But then many must have asked that why did the bike come with a supercharger and not a turbocharger. Well the answer to the question lies in this very article as to why a supercharger was preferred and why they are better for motorcycles than turbochargers.READ MORE: What Are Superchargers And Turbochargers?
It all comes down to the specific functioning of that part. So we first need to understand what both these are and how they exactly function so that it becomes easy for us to understand which is better for motorcycles and which is not. Do note that the explanation will contain a lot in terms of cars, but the qualities are transferable and relatable and the comparison is done so you can understand properly.
Turbochargers:
Turbochargers are a way of forced induction for an IC engine to provide an additional boost to the vehicle using the waste energy from the engine, i.e. the exhaust gases. So in case of turbochargers, it is connected to the outlet of the exhaust gases from the combustion chamber and hence when the exhaust gases leave, they still do have quite some energy left in them which is used to rotate the turbo turbine inside. These gases when are able to rotate the turbo turbine to a peak RPM, then is when the turbo makes some power useful for the vehicle and then we get what we call a turbo boost.
Now turbochargers are awesome because they allow the engine to produce more power in the same cubic capacity and also improve the fuel efficiency as well since the engine idles better as well. So all in all turbos are great; but then when we take that from a motorcycle point of view, there are certain issues that come up which we will come to in some.
Superchargers:
Now superchargers are also forced induction type of system to increase the power of the vehicle, but they do not use the exhaust gases but the power from the engine itself. This means the supercharger is connected to the crankshaft of the engine itself and draws engine power for its functioning. Now if you say that if that is the case then there should be engine power drop and not power boost. Well, you are right, but only half of it. Yes, overall the power delivered on the crank does decrease, the same way when you switch on the AC of the car and the power to the wheels drop a little.
But then the power generated by the supercharger is quite much that we all put together the figure comes out to a boost. Yes, the number might still be less than that of a turbo, but it is still quite enough to give the vehicle a significant boost. Also there are no lags in superchargers like turbos. The power amplification in superchargers is quite high and most importantly they do not have a threshold to deliver power. They can do so from the word go.
Turbochargers are a way of forced induction for an IC engine to provide an additional boost to the vehicle using the waste energy from the engine, i.e. the exhaust gases. So in case of turbochargers, it is connected to the outlet of the exhaust gases from the combustion chamber and hence when the exhaust gases leave, they still do have quite some energy left in them which is used to rotate the turbo turbine inside. These gases when are able to rotate the turbo turbine to a peak RPM, then is when the turbo makes some power useful for the vehicle and then we get what we call a turbo boost.
Now turbochargers are awesome because they allow the engine to produce more power in the same cubic capacity and also improve the fuel efficiency as well since the engine idles better as well. So all in all turbos are great; but then when we take that from a motorcycle point of view, there are certain issues that come up which we will come to in some.
Superchargers:
Now superchargers are also forced induction type of system to increase the power of the vehicle, but they do not use the exhaust gases but the power from the engine itself. This means the supercharger is connected to the crankshaft of the engine itself and draws engine power for its functioning. Now if you say that if that is the case then there should be engine power drop and not power boost. Well, you are right, but only half of it. Yes, overall the power delivered on the crank does decrease, the same way when you switch on the AC of the car and the power to the wheels drop a little.
But then the power generated by the supercharger is quite much that we all put together the figure comes out to a boost. Yes, the number might still be less than that of a turbo, but it is still quite enough to give the vehicle a significant boost. Also there are no lags in superchargers like turbos. The power amplification in superchargers is quite high and most importantly they do not have a threshold to deliver power. They can do so from the word go.
So Which Is Better For Motorcycles?For starters, motorcycles are compact vehicles. So lesser and lighter the better. That also means when there is an immediate power surge, the power to weight ratio is really high and apparently that sudden surge can be really dangerous for the bike both in theory and practical. Turbo boosts are available only after a certain RPM and then there is a sudden rush of power which drives the vehicle. But in case of bikes, these could become a huge issue because as it is the bikes are higher revving, so the turbocharger will be functional only after a bit more higher revs and until then the bike would be already in motion.
Now adding to the original power when the power surge happens, there is a very good chance that the bike will lose traction and extra force exerted might not be possible to tame for the rider as well as the bike and hence could result in crashes due to the loss of traction. This is one thing that turbos could do. Another issue is that bike engines are cramped up and are in compact spaces, so adding a turbo will be an issue. Add to that the turbo uses exhaust gases which are really hot. Hence there will be added heating in the turbo and there will be need for it to be cooled up to avoid it from melting. That calls for additional plumbing for coolant to cool the turbo or more load on the engine oil for the same.
But when we consider all these things for a supercharger, all the issues in case of bikes are take care of. The supercharger works off engine power, hence it just rotates by itself and hence there is no excessive heating that needs taken care of. Add to that the power delivery is available from the word go, hence there is no stress that comes up later on and the bike can hence be made in accordance to that. The supercharger can be connected to the engine easily and there are no major complications in this case.
So when we look at it that way, we can easily conclude that yes, even though practically turbochargers are better than superchargers in terms of performance and power output and even efficiency, but in case of motorcycles, working with turbochargers does not make much practical sense in terms of design, implementation and the use. Hence superchargers win the day here.
By: Pratik Patole