Why Do Honda Dirt Bikes Have Dual Exhaust?

This is the first 250F with a completely independent exhaust system from the port to the muffler tip. Dual exhaust ports were once utilized on four-stroke dirt bikes to let larger displacement thumpers rev faster and farther.

Which dirt bike from Honda has dual exhaust?

Both single and dual exhaust systems are produced by FMF for the 2019 Honda CRF450. Due to its greater performance in the past, we have favored the single exhaust. However, we believed that by omitting to test the FMF Factory 4.1 RCT dual system, we were doing a disservice to CRF450 users.

Is dual exhaust preferable to single exhaust?

Your car will look fantastic if you put dual exhaust tips on a single exhaust, but no power will be gained. Due to the engine’s improved ability to breathe, dual exhaust will significantly increase your power. Thus, dual exhaust may be worthwhile if you want to improve horsepower. The intake manifolds must be replaced with headers, followed by the necessary pipework, converters, and mufflers.

What purpose does a dual exhaust serve?

In essence, a dual exhaust system improves engine breathing, resulting in a more thorough combustion cycle. It produces more exhaust faster, which enables the engine—which is essentially an air pump—to draw in more air more quickly and produce more horsepower.

Are two exhausts louder than one?

Although the sound an exhaust makes is primarily ornamental and has no bearing on performance, it can influence your preference for a dual or single exhaust. Single exhausts from the factory won’t have that potent sound right away. For a more imposing presence on the street, many aftermarket single exhausts will give a richer, deeper sound note. There are exhausts available that will have a moderate sound or come with an optional suppressor that you can attach to lessen the tone if you don’t really like that loud exhaust note. Dual exhausts, however, will offer that louder, throatier sound note that fans of muscle cars want in comparison to single exhausts. The design will greatly decide what kind of sound a dual exhaust will generate, depending on whether you choose an H-pipe or an X-pipe. A dual exhaust with an H-pipe will give the familiar, smooth sound of an old-school muscle car, whereas an X-pipe will sound louder and more aggressive.

What makes a two-stroke exhaust so large?

The expansion chamber in question is what is employed to improve the engine’s horsepower (see this page for a photo). This method is used frequently on dirt bikes but not on street bikes because it only works on two-stroke motors. Four-stroke engines are the norm for street bikes.

Utilizing the momentum and pressure of the exhaust gases to create a pump that forces more air and fuel into the cylinder during the intake stroke is the fundamental concept behind an expansion chamber. It performs similar tasks to turbochargers, but without the need of mechanical parts.

You already know that the exhaust and intake portions of the cycle overlap if you’ve read How Two-stroke Engines Work. The exhaust port is first exposed as the piston descends, allowing the majority of the exhaust to exit. The intake port is then opened to let in fuel, oil, and air. A well calibrated expansion chamber facilitates the intake process in two ways:

  • A vacuum is produced at the exhaust port as the exhaust gases expand into the expansion chamber. Fuel, oil, and air are drawn into the cylinder by the vacuum.
  • Any gasoline, oil, or air that was pushed through the exhaust port is forced back into the cylinder as the shock wave of the exhaust pulse hits the end of the expansion chamber and echoes back. This page contains a lovely diagram that explains the procedure.

The expansion port has the effect of packing more fuel, oil, or air into the cylinder with each stroke by pulling extra through the cylinder and then pushing it back in. This increases engine power in a similar manner to how a turbocharger does.

What is the HP increase from a dual exhaust?

The car may experience back pressure and other bottleneck blockages, which will reduce its horsepower. Adding a second exhaust pipe allows the engine to release twice as much exhaust, increasing horsepower by giving each manifold its own structure.

Simply said, installing a dual exhaust system can increase horsepower by 15% to 20%. For instance, a car with 200 horsepower will likely add 30 to 40 horsepower.

Therefore, it will be crucial to get the muffler removed as quickly as possible. True performance exhausts are almost always installed as part of bigger cat-back layouts.

Can a single exhaust be changed into a dual exhaust?

My name is Josh, and I was wondering if I could upgrade my truck’s exhaust system. I already possess an extreme cherry bomb with a 3.5 inch dump. My engine’s current exhaust system consists of two ‘Y’-shaped pipes that link in the centre and come out of both sides of the engine. If I could replace the Y portion with another cherry bomb extreme, another 3.5-inch dump, and a catalytic converter, that would be ideal. It would be fantastic if you could let me know if it would pass smog inspection. Oh, and it has a 5.7L stock 350 engine.


A smog check failure will result from removing the Y pipe and changing your truck’s current “single” exhaust system into a “dual” system.

Your alteration will be viewed as a “tamper” by the smog inspector. The manufacturer’s original exhaust system layout for your car must be maintained. The fact that the conversion was not done at the factory will make the vehicle fail the smog inspection, even though switching to a dual system and adding a second catalytic converter reduce emissions.

How much does a dual exhaust system cost to add?

Your Camero will gain horsepower if you upgrade to a real dual exhaust; on the low end, it can cost you roughly $1,200. However, the price will change based on the materials you select and the labor rates in your city.

You’ll need to change more than just the exhaust pipe if you want to give your engine a boost, like:

  • bowed pipe
  • Headers
  • converter catalytic
  • Mufflers

This kind of car modification might cost closer to $8,000 if you choose for a premium titanium dual exhaust. Check with your auto insurance carrier before making any modifications to your vehicle to be sure they are still street legal and covered by insurance.

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If yes, how do they alter sound?

Since they are practically at the conclusion of the exhaust system, exhaust tips give a car a louder sound. However, the exhaust sound will normally only be slightly altered with a standard tip. The sound of the engine will be stronger and heartier with a larger tip, while a smaller tip will sound raspy. This is where researching various exhaust tips for your car can be beneficial. The sounds and fashion you desire will be clear to you.

Are H pipes required?

On all genuine dual exhaust systems, Flowmaster highly advises utilizing a crossover tube, also referred to as an H-pipe or balance pipe. The crossover pipe balances the exhaust pulses and enables sound waves from both engine banks to communicate with one another.

Straight pipe: Does it harm engines?

The majority of people frequently mistake an exhaust system for a drain pipe.

The effectiveness of the drain increases with pipe size. This is false for the following reasons:

1. Exhaust gas has been heated. The gas cools as it passes through the catalytic converter, muffler, and exhaust manifold. The gas’s density increases as it cools. The velocity alters as it gets denser. You don’t want the exhaust gases to either cool down too rapidly or to remain hot for too long.

2. The volume of exhaust gas varies with RPM. Your engine is putting out a lot of hot exhaust gas while it is at redline. It isn’t creating much when it is at rest. An exhaust system that performs well at 5,000 RPM will therefore be too large for an engine running at idle. Similar to an exhaust system tuned for 2,000 RPM, one tuned for higher RPMs will be at least somewhat restrictive.

The first thing a race crew does when they get their hands on a stock car is swap out the factory exhaust for a larger aftermarket system without a muffler. Race vehicles do this because they spend the majority of their time moving at high RPMs. When attempting to enhance top end performance, a huge, unrestricted exhaust is a terrific choice. When the engine is running as quickly as it can, you want an exhaust system that makes scavenging easier.

On the other hand, if you’re operating a vehicle on the road, your average RPM will fall between 1,500 and 4,500 RPM. Your engine will typically be running at 2,000 RPM or less. The factory exhaust system on your car is therefore built (and tuned) to allow scavenging between 1,500 and 4,500 RPM.

As a result, installing an exhaust system a la race car is not a good upgrade for a street car. At stop signs and on freeway on-ramps, street cars must operate well. For instance, the exhaust gas velocity can rise in a straight pipe. This will probably lower engine output below 2,000 or 2,500 RPM, making it a little more difficult for your car to accelerate from a stoplight. On a dyno, your engine may display more horsepower and may even complete the quarter-mile a little quicker, but it won’t be faster on the road.