Is Dual Exhaust Better Than Single On A Motorcycle?

Dual exhausts. They look powerful and aggressive as hell – usually seen on larger and more powerful bikes. But looks aside, are they actually better? Do they give you more horsepower? More sound? Or are they just for looks?

Truth is dual exhausts are less restrictive and they allow exhaust gases to escape quicker – which helps in reducing back pressure and increasing performance. 

Dual exhausts are only beneficial for more powerful and bigger engines. Simply swapping single to dual exhaust won’t give you much horsepower – maybe just a little  on higher RPM. 

Surely you have more questions. Which is why I am gonna be explaining all about dual exhausts vs single exhaust in this article. Now take a cup of coffee (or whatever you drink) and read on.

Dual exhausts system is when a motorcycle has 2 exhaust pipes connected to it’s engines – allowing more exhaust gases to escape at once. Whereas a single exhaust system only has one.

Single exhaust motorcycle

Before we dive deeper into comparisons, let’s first understand motorcycle engines and their exhausts. What’s the big deal?

Every motorcycle engine is a combustion engine. Which means, the engine uses air and fuel to generate combustion and deliver power to the wheels.

To have more horsepower, you will need bigger combustion – which means more air and fuel. Injecting fuel is the easier part. Getting in more air is challenging. This is where less restrictive dual exhausts come in the picture. 

You see, a combustion is basically an explosion that generates exhaust gases as byproducts. These exhaust gases must escape the combustion chamber as quickly as possible to give room for fresh air to enter again. 

Dual exhausts have 2 exhaust pipes – allowing more exhaust gases to escape at the same time. Which means, the combustion chamber will have more room for more oxygen in the next cycle.

And if you still remember, more air + more fuel = more horsepower.

2 into 2 dual exhaust

This works very well in theory. But in the real world, there are more factors to consider. What type of dual exhausts are we talking about? How big is the engine size?

Things like these impact the horsepower gains. It’s not as simple as just saying dual exhaust is always better than single (because it’s not always better!).

I figured when you ask if dual exhaust is better, you are referring to more horsepower. If that’s true, then you are in luck.  I will be talking about horsepower gains next.

Dual exhausts have the potential to give you more horsepower but it only works on bigger engines. Fitting dual exhaust on a tiny engine will not give additional horsepower – even if it does, it will just be a small boost in the higher RPM range. 

Dual exhausts – as I said, help you get rid of exhaust gases much quicker. More exhaust gases can travel at once and exit the combustion chamber. Which means, more room for air and fuel in the next combustion.

When your motorcycle engine is big, it has enough room to accommodate more air and fuel to generate a bigger combustion (and more power). 

On smaller engines, no matter how much faster exhaust gases exit, there’s not enough room for more air and fuel. The performance ceiling is capped. 

If you care about performance, you should go for a 2 into 1 dual exhausts. I will talk more about this down the article. So read on. 

Pros & cons are probably the best ways to directly compare something. So here it is – how a dual exhaust is better and worse when compared to single exhaust.

Then you be the judge and tell me which one you think is better (for you). 

Dual Exhaust Pros

1. More horsepower (on high end). Dual exhausts can give you more horsepower, provided that your engine is big enough to accommodate them. Otherwise, expect to see more power only at the higher RPM range.
2. Decreased backpressure. Dual exhausts means more exhaust gases can escape at the same time. This will relieve back pressure – if you are technical and you care about this. Less back pressure is always better for performance. 
3. Looks more aggressive. Personal preference – but dual exhaust just gives more of that sporty and aggressive look. I am sure your crush or your partner thinks they are.
4. Cooler temperature engine. Having exhaust gases quickly leaving the bike will provide you with a cooler temperature engine – which means more efficient engine, lesser pressure and lesser wear and tear.

Dual Exhaust Cons

1. They are heavier. Weight plays a big role in motorcycles. Dual exhaust is unfortunately heavier – due to the extra piping and end-can. This extra weight can even slow you down. 
2. More expensive. Being more complex with more parts, dual exhaust systems are more expensive to purchase, install and fix.
3. Quieter. This depends on the engine, but with an apple to apple comparison – dual exhausts with 2 end cans has 2 mufflers. Surely the extra muffler will provide even more silencing? I will talk more about this below.

Dual exhausts are not always quieter or louder than a single exhaust system. Bikes with dual exhausts from the factories are usually louder because they come with bigger engines – this is not because of the dual exhaust. 

Generally, bikes with dual exhausts systems are louder than single exhaust. Which makes people believe that dual exhausts make your bikes become louder – this is not true. 

The two things that impact motorcycle sound is the engine and muffler. The bigger the engine, the louder the sound – same goes to muffler (generally). 

Motorcycles that come with dual exhausts from the factories are usually equipped with bigger and louder engines. The engines themselves are loud. The dual exhausts do not help to make the engine louder (in fact, it’s the opposite). 

If you are simply switching from a single exhaust to dual exhaust, you will end up with the same engine and an extra muffler. Which means the engine sound will be silenced even more.

The best dual exhausts system for performance is 2 into 1 dual exhausts – they are lighter (no additional end can) and are great at preventing exhaust reversion. 

2 into 1 exhaust system is where the exhaust starts with 2 pipes but combined into 1 at the end. This means you only have 1 muffler (“end” can) and much lighter weight. Again, remember that weight plays a big factor in motorcycle performance.

2 into 1 dual exhaust

2 into 1 exhaust also works great for preventing exhaust reversion. If you don’t already know, exhaust reversion is when the exhaust gases are flowing backward – causing an increase in air pressure. 

You see – when exhaust gases flow, they flow in pulses. When each pulse reaches out into the atmosphere, they might be pushed back (depending on how much energy is left in the pulse). 

This is natural and it happens in any exhaust system. However, 2 into 1 exhaust works great to reduce this because they only have 1 exit point – the exhaust reversion only happens from 1 point. 

Had you installed a 2 into 2 exhaust, then exhaust reversion can happen from both exit points – further increasing back pressure and potentially decreasing horsepower.