Exhaust is usually the most common thing to upgrade on a motorcycle – but how much horsepower can it provide really? There are many types of exhaust setups you could do.
A full system exhaust setup with a jet kit could provide you with additional 10 horsepower, whereas just replacing the end can could give you only 3 horsepower. So it really depends on the exhaust setup you have.
In this article, I will walk you through the common setups that enthusiasts have on their motorcycles. And for each, we will discuss what they are, how they provide power and how much additional horsepower they can provide!
Expected Horsepower Gain From Each Exhaust Setup
Here’s a summary of the exhaust setups and their expected horsepower gain.
Mind you that horsepower gain varies from each motorcycle engine. The gain is usually a percentage to the current horsepower. Bigger engines could yield more horsepower from modification.
In this article, I would not be showing you percentages. Instead, I will give you the rough figure – assuming that the modified motorcycle has a 100 horsepower as base.
|Exhaust Setup||Expected Horsepower Gain|
|End can||3 horsepower|
|Full system||7 horsepower|
|Full system with Jet Kit / Tune||12 horsepower|
If you have decided to go with the “full system exhaust with jet kit and tune” because they provide the most horsepower then wait just a moment! That’s not what you should do.
You need to choose the right exhaust setup that’s suitable for you – especially when it comes to your budget and goals.
Going with a full system exhaust with a jet kit and tune would give you the most horsepower but they are also most expensive!
Let’s go through each set up individually – so you know the pros and cons. But before that, let’s first understand how a motorcycle engine generates power and what we need to do to improve that.
How Motorcycle Engine Generates Power
Motorcycle engine is very similar to a car’s engine. They both generate power by mixing air and fuel to create combustion. Combustion – if you don’t already know, is an explosion that generates power and exhaust gases.
If you want more power, you need more fuel and air. Getting more fuel is the easy part, your motorcycle’s computer (CEU) can just inject more (a bit more complicated but this is the gist).
Getting more air is the harder part. Aftermarket exhaust aims to increase the amount of air for combustion by allowing exhaust gases to flow out easily. This is what it means by being less restrictive.
Exhaust gases can flow easily means that they will exit the combustion chamber much quicker – allowing more air to enter the combustion chamber for the next cycle.
What’s “End Can” On Motorcycles?
End can is also known as a slip on exhaust. It only replaces the end of your motorcycle exhaust system – which means the muffler. This makes your motorcycle sound and looks better but does not have much gain on horsepower.
Expect to get only 3-5 horsepower from a new end can. Most enthusiasts replace their end cans to improve the sound and looks of their motorcycles (not for power).
End cans are typically the only visible component on a motorcycle’s exhaust system – the rest (header and mid-pipe) are hidden behind the motorcycle’s body work.
End cans can start at around $200 without installation. Installation should be easy though – typically it only involves a clamp. They are called slip-on exhaust for a reason!
End Can (Slip-on Exhaust) Pros:
- Improves motorcycle sound greatly. The “end can” contains a muffler – which is responsible for altering engine sound before they exit into the environment. Pro tip is to hear before and after sound on YouTube before buying one.
- Improves motorcycle appearance. The “end can” is the only visible component on your exhaust system. You could change the way your motorcycles look by replacing the end can.
- Relatively cheap. The “end can” is the cheaper option if you want to upgrade your motorcycle’s exhaust system. The good ones can start at around $200
End Can (Slip-on Exhaust) Cons:
- Small horsepower gain. Replacing the “end can” alone will not yield you much horsepower. Expect to gain 3-5 horsepower. Actually, don’t expect anything at all – the gain is too small for you to even feel it.
- Not much weight saving. If you care about the weight of your motorcycle, then installing an “end can” will not reduce that much weight.
What’s “Full Exhaust System” On Motorcycles?
Full exhaust system is where you replace the entire exhaust system from the header to the end. This means you will replace below components:
- Exhaust header
- Mid Pipe
- Catalytic Converter
- Muffler (the “end can”)
Replacing the entire system yields you even more horsepower than just a slip on exhaust. This is because you could reduce the restriction in the entire exhaust – allowing the gases to move out quickly.
Full exhaust system without any tuning could yield you about 7-10 horsepower. But they are much more expensive than a slip-on – expect to pay at least $500 to over $1000 for the full system.
Horsepower aside, a full system also provides you with a much better engine sound. This is because the stock muffler is also changed into a less restrictive one.
Make sure you listen to the before and after sound comparison when choosing. I am sure you could find them from online forums or YouTube videos.
Full Exhaust System Pros:
- Horsepower gain. With a full system, expect to gain about 7-10 horsepower depending on your engine. A full system will yield much more horsepower than just a slip-on.
- Huge weight saving potential. If you care about the weight of your motorcycle, replacing the full stock system into an aftermarket system can save you a lot of weight. This is because a light weight material can be used on all its components: header, mid-pipe, muffler, etc. You can expect to lose about 20 pounds.
- Improves motorcycle sound. Full exhaust system also replaces your existing muffler. Which means your motorcycle will sound much better!
- Improves motorcycle appearance. You could choose a full exhaust system that has an aggressive looking “end can”’ – making your motorcycle look even more badass.
Full Exhaust System Cons:
- Expensive. A full exhaust system is much more expensive. Be prepared to spend at least $500 on just the product. This does not include installation yet. A high end system could even go beyond $1,000.
- Hard to install. If you are installing a full exhaust system yourself, then prepare to get your hands dirty. You need to work with multiple components like headers and midpipe while making sure other components like O2 sensors and CATs are installed correctly. Otherwise your dashboard will be looking like a christmas tree with all warning indicators.
What’s “Tuning” On Motorcycles?
When speaking about aftermarket installation, tuning usually means updating the fuel injector or carburetor to make sure fuel / air ratio is optimal.
By now, you already know that motorcycle engines use a mixture of fuel and air to create combustion and power. This mixture must be in the perfect ratio – otherwise you will have weak performance or horrible fuel efficiency.
After installations like an aftermarket exhaust, your engine should now have more air in the combustion chamber / cylinder. What’s left is to inject more fuel to create a bigger combustion – resulting in more horsepower.
The computer on modern motorcycles should be able to automatically adjust and inject more fuel. However, tuning is still required to get a perfect ratio.
On motorcycles that use a carburetor to manage air / fuel ratio, you will need to install a bigger jet kit – also known as rejecting the carb. Bigger jet kit allows the carburetor to supply more fuel at a given time – recommended if you have aftermarket exhaust.
On motorcycles that use fuel injector to manage air / fuel ratio, you will need to bring your motorcycle to a mechanic for dyno tuning. The mechanic will evaluate your current motorcycle setup and adjust the configurations in the ECU where necessary – to achieve the perfect air / fuel ratio.
If you are installing a new “end can” (slip-on exhaust), then you won’t need any tuning. The exhaust flow is not impacted as much and your motorcycle will run just fine.
If you are replacing the entire exhaust system, AKA full system, then you will want to bring your motorcycle for a tune. Without tuning, the horsepower gain will be minimal.
Expect to gain another 5 horsepower (totaling to 12 horsepower), if you get a tune after installing a full exhaust system.
Motorcycle Exhaust Setup: My Recommendation
If all you care about is an improved sound and better looking motorcycles, then go for the slip-on exhaust. They are cheaper, easy to install and don’t require tuning.
If you are all about that performance and have more budget, then you could give a full exhaust system a go. They provide much more horsepower to your motorcycle and provide you with all the benefits that a slip-on does.
Just make sure you bring it to a tune as well after the installation.