Glasspacks vs Straight Pipe – What Are The Differences?

What your vehicle's sound is a big part of the car's personality. Getting an aftermarket exhaust is popular because it changes the car's sound. We have consulted automotive experts on the difference between glasspack and straight pipe exhausts. Here is what we got from them.

The main difference between a glasspack and a straight pipe is that a glasspack has a layer of fiberglass inside, while a straight pipe is pure exhaust tubing. 

Glasspack and straight pipe exhausts are a cheap alternative to give your vehicle a different exhaust note and more power. For more information about a vehicle's exhaust, keep reading below. 

Under side of a car showing the titanium exhaust pipe, Glasspacks Vs Straight Pipe: What Are The Differences?

Glasspack Vs. Straight Pipe

Choosing to install a glasspack or straight pipe exhaust is an excellent alternative to a full exhaust system which could cost you a few hundred dollars to a few thousand. Also, they are plentiful and can be installed in any car or truck.

Showing the underside of a car revealing the titanium exhaust manifold

Getting the right aftermarket exhaust is essential because it will ultimately change the overall sound of the car. Below you can find and compare the differences between a glasspack and straight pipe exhaust.


glasspack is an aftermarket muffler that is just an open hole with louvers inside it. It is very similar to a straight pipe, but its core has fiberglass. 

For most glasspacks, if you look inside, you'll see a bunch of louvers that give it a cheese grater look. These louvers affect the sound waves and airflow of the vehicle.

The sound waves go through it and get scooped up in the louvers, then shout out to the core where the fiberglass insulation is. Because the glasspack has many louvers that reduce the diameter of the pipe, this lowers the car's performance a bit. 

For glasspacks with louvers, there will be an indicator of where the front of the pipe will be. The solution other people do to reduce the drag created by these louvers is to install the glasspack backward.

Some glasspacks have perforated cores that don't have these louvers, only the holes drilled into the pipe. Most of the time, perforated cores will sound louder since the pipe does not have that much obstruction.

Glasspacks can be made short and used just as resonators or lengthy and used as mufflers. Glasspacks sound best on muscle cars or vehicles with V8s because they can give the car a bit of a raspy tone.

Straight Pipe

Just as its name says, a straight pipe is a straight pipe that acts as the vehicle's exhaust. A straight pipe exhaust typically starts from the headers to the back or wherever you want the exhaust to exit.

Unlike glasspacks, a straight pipe is just a plain aluminized or stainless steel pipe; there are holes, louvers, or core packing. A straight pipe will give your vehicle a loud, but natural engine tone and is one of the cheapest options to increase the vehicle's exhaust airflow.

The loudness of your vehicle and power output will also differ depending on the pipe's diameter. For exhaust systems, there are recommended diameters for a pipe's size. Having a pipe's diameter too small or big can decrease your vehicle's performance.

Note that if you're planning to get to install straight piping from the headers to the back, you will be losing your muffler and catalytic converter. But you gain a few horsepower and torque. That's why this exhaust mod is very popular for people who are into motorsports.

Is Installing A Straight Pipe Illegal

Blue backend of a car with carbon fiber spoilers and high end titanium exhaust pipe

Though some people may love the sound of a roaring engine or a great exhaust note, this is not the case for many people. That is why laws prevent a person from having a car that is too loud.

Straight piping a car is a fast way to gain a bit of horsepower and torque to a vehicle without spending hundreds or thousands of dollars all at once. But not all states allow this modification. 

Most states, especially ones with large cities, have rules on how loud a car's exhaust can be. An example of this is California, where your vehicle's loudness can't exceed 95 decibels. If your car has been found to exceed this threshold, you may be fined.

It is best to check up on your local laws about vehicle modification since there is also some law preventing you from removing the car's catalytic converter. It's best that you only straight pipe a car you'll use on a race track and not your daily vehicle.

In the end, some states allow your vehicle to be straight piped as long as you don't exceed the volume threshold, while in other states, it is illegal. Always double-check your state's law on vehicle modification. This can save you a lot of time and money and keep you on the safe side of the law.

How Much Does A Vehicle's Exhaust System Cost

Heavily modified Audi R8 converting it to a dragster

When planning on building your car for increased performance or looking for replacement stock parts, you must know the prices of the components you're buying to avoid overspending. With car exhaust, prices will vary depending on the build quality

Car mechanic taking apart the rusted exhaust manifold

Below are the most common exhaust systems you'll find on the market or in an auto supply shop. 

Stock Exhaust

For stock exhaust, you are roughly looking at a price range of $300 - $600. The price of a vehicle's stock exhaust system can vary depending on the car's make and year model.

The more you a car on the road, the higher the chances of finding a cheaper deal on a stock exhaust system for your vehicle. If your car is relatively new, you can inquire at the dealership you bought your car from if they are offering a stock exhaust system.

A cheaper but time-consuming alternative to finding a stock exhaust is in a wrecked or salvage yard. Some yards will allow you to parts out a car in their inventory. This will be a lot cheaper compared to ordering one from a dealership.

Straight Pipe

Straight piping is the way to go if you want your vehicle to sound more aggressive and gain a bit of horsepower and torque without breaking the bank. Commonly seen on highly tuned or modified vehicles, this is a cheap and easy way to get more power.

Straight piping is excellent if you have a project car and don't have the money to spend on an aftermarket exhaust system. To straight pipe your vehicle, you will need around $200 - $600. The price may vary depending on if you will do all the work or if a shop will.

One important thing to remember is straight piping is not legal in all states. Before adding these, make sure that you're not breaking any laws. But if you plan to do this on a track car, this is fine as long as you only drive it on a race track.


Backend of sport racing car showing two exhaust pipes

There is no reliable average price range with aftermarket exhaust since there are exhaust systems worth $600, while others could cost above $4,000. A vehicle's make and model will also have an impact on the price.

If you drive a less popular vehicle, it will tend to have fewer aftermarket parts. With this, you will have to custom make an exhaust system. Custom-making components can be costly since you will need to pay for materials and labor.

Also, if you are in the market for high-performance exhaust systems for your car or truck, aftermarket parts should be your go-to. There are a lot of high-performance exhaust systems made by brands that have been in the market for years.

Brands such as HKS, Borla, Flowmaster, and GReddy are a few brands that make high quality and performance exhaust. These brands focus more on motorsport but have street performance exhausts if you still want your vehicle daily.

Getting an exhaust system from one of these brands will be costly, but they are a great choice if you want to get the best performance out of your car. When getting an aftermarket exhaust, be sure you know what you want your car to be.


Under side of a car showing the titanium exhaust pipe

The main difference between a glasspack and a straight pipe is that a glasspack has fiberglass in its core, and for some, they have louvers. The glasspack and straight pipe may be made differently, but in the end, they have a similar purpose, which is to provide the vehicle with better airflow.

When choosing to replace your exhaust system, make sure that you check your local law about vehicle modification. Some states will be looser about exhaust mods while others completely ban loud exhaust.

For more automotive topics and tips, check out the following post.

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