Does a Muffler Delete Add Horsepower? Car Myth Busted

As far as car mods go, a muffler delete is probably the best bang-for-your-buck that you can get. It makes a huge difference in sound and loudness, while only taking up an hour or two of your time. 

To add even further, you can easily do most of it if not all of it in your driveway with only a few hand tools.

But what about power figures? Does a muffler delete add horsepower?

Does a Muffler Delete Add Horsepower?

Depending on the design of your car’s exhaust system and how restrictive the stock muffler is, a muffler delete will add 1-3 HP at best and 0 HP in most cases. Even then, that minuscule 1-3 HP power increase cannot be felt, since our bodies can only feel a 10 HP increase. 

With that said, a muffler delete has the potential to shift your car’s torque curve slightly higher in the RPM range. This means slightly more torque at high RPM and slightly lower torque at low RPM. Neither of which can be felt. 

Now, why does a muffler delete add so little HP if at all? The reason for that is that the stock mufflers really aren’t that restrictive. Even with all these baffles and chambers, stock mufflers are designed to maintain close to zero back pressure. 

That means that by deleting the muffler back pressure does not change and the exhaust velocity (most important part) stays practically the same. 

Muffler Delete Pros and Cons

Okay, so a muffler delete will not add your car any meaningful increase in horsepower, but so what? A muffler delete adds massive style if done right, especially on turbocharged cars which do not sound loud without a muffler. For example, this Volvo:

Even without adding power, a muffler delete will completely transform how your car sounds. Here are the pros and cons of doing a muffler delete.

How Much Does a Muffler Delete Cost?

Muffler deletes are cheap and give huge results. If done by yourself, a muffler delete will cost you $20-$30 for the exhaust cutter tool (if you don’t have any way to cut off the muffler), and $50-$80 to fabricate a piece of pipe in the muffler place. You can’t just cut off the muffler and leave the pipe dangling underneath the car. 

At a muffler shop, a muffler delete will set you back by $80 to $100 for cutting off the muffler, fabricating a replacement pipe, and welding/clamping it in. 

Things You Need To Consider Before Doing a Muffler Delete

Before you go out and delete your car’s muffler, there are a few things that you should think about and consider first, since muffler deletes are a bit more involved than they might sound. 

Fabricating a New Pipe in Place of the Muffler

This is by far the most annoying part of the muffler delete. However, it has to be done.

Apart from reducing sound, the muffler extends the exhaust pipe past the bumper. With the muffler deleted, your exhaust will end underneath the car, somewhere along the rear axle. This is a big problem because the hot exhaust gases will cook your fuel tank, which is not only illegal – it’s also dangerous.

To prevent that, you’ll need to replace the muffler with a pipe. Thus, you have two options: fabricate the new pipe yourself or pay a muffler shop to do it for you.

To fabricate the pipe yourself, you’ll need a welder at the very least, and a hydraulic pipe bender if you want to do it properly. Thus, unless you have a welder, you’ll have to pay a muffler shop to do it for you. Muffler shops will likely charge you $50 to $80 for fabrication and metal, which is not bad at all. 

4-Cylinder Engines Sound Better With a Muffler

Muffler deletes are loud (obviously), therefore they’re best done on turbocharged cars, V6s, and V8s. I personally would not recommend doing a muffler delete on a naturally aspirated 4-cylinder (unless it’s a Boxer with uneven headers), as it will probably be too loud and only highlight the high-pitched, annoying shrieking exhaust frequencies that most people hate about them.

In that case, you might be better off with getting a chambered style muffler that is specifically designed to highlight better-sounding exhaust notes on 4-cylinder engines. It will still be pretty loud but just reduce the high-pitched shrieking a bit. 

With that said, it doesn’t mean that you shouldn’t try and check it out yourself and see if a muffler delete works well for your car. The best part is that you can put the muffler back on just as easily using exhaust clamps. 

Final Thoughts

While muffler deletes can make your car sound badass, they usually do not add any horsepower because the stock muffler is not that restrictive to begin with. 

But that shouldn’t stop you from doing a muffler delete. You can always install the old muffler back if you don’t like how your car sounds with a muffler delete.