Muffler Delete vs Resonator Delete – Pros and Cons Between Them

Getting a more potent sound to come out of the exhaust requires a careful balance of volume versus noise. Most manufacturers tend to overdo the quieting of the exhaust – whether it’s to streamline their production based on the most strict regulations, or for marketing. However, if we want to experience the full potential of the engine, some of the components have to be removed.

In this piece, we’ll go through the pros & cons of deleting the muffler and/or deleting the resonator. If you’re looking for a short answer – deleting the muffler while keeping the resonator is the best in terms of balance between engine sound and pure noise. 

How do Mufflers & Resonators Work?

Mufflers are the large cylinder near the end of the exhaust system and serve to reduce the noise produced by the engine.

Cutting a muffler in half would reveal the resonator chambers consisting of pipes, perforations, and empty space designed to bounce the sound around, reducing its volume. Mufflers reduce sound across the spectrum, from the idle RPM to the redline. They also slightly reduce the amount of drone, hum, and other unpleasant noises.

Resonators are mounted before or after the muffler, or even on both sides. Their primary purpose is to alter the sound produced by the engine.

Mufflers and resonators have inverted purposes. A muffler primarily lowers the volume, while noise reduction comes second. For a resonator, altering the sound is the primary function, while volume reduction is less of a priority.

You’ve likely experienced the unpleasant frequency of a washing machine, vacuum cleaner, or an angle grinder. There are certain frequencies that are intolerable for the human ear and the engine of your car creates them as well.

The exhaust system on its own does a lot to dampen and shape the sound coming from the engine, but it’s the resonator’s job to handle those crucial frequencies and mitigate the droning or humming noise.

A standard exhaust system consists of pipes that connect the exhaust manifold to the catalytic converter, resonator, muffler, and exhaust tip. Engines with larger displacements and 6 or more cylinders have two exhaust systems, doubling the number of resonators and mufflers.

1. Sound Quality

In terms of sound improvements, if you have to remove one, deleting the muffler is a much better deal than deleting the resonator.

Because muffler dampens the sound across RPM, you’ll get a louder, raw sound coming out of the engine. Removing the resonator will only give you a headache, especially when idler or when you hit the ideal RPMs on the highway. Deleting both the resonator and muffler is the worst option that is guaranteed to make the ride intolerable.

2. Power Boost

There’s a lot of misconception about what modifications give you a power boost. Deleting the muffler, resonator, or both will not give you any noticeable increase in power. You might get up to 1% at best, but the increased noise will affect your driving ability to a much greater extent. In other words, you may even lose performance by deleting the resonator and muffler.

In the Straight Pipe Exhaust Cost & Benefits article, I said that modifying the exhaust system can get you a slight power boost. Since then, I’ve actually done some work on one of my diesel Audi, and I can confirm that it works.

I deleted neither the resonator nor the muffler, and instead cleaned my turbocharger, and more importantly the catalytic converter. The result was a faster and more precise response from the turbo and a subjective power increase of at least 20%.

My Audi didn’t actually become 20% more powerful, but rather, I helped it regain that 20% back. The catalytic converter is basically a big filter designed to catch exhaust particles, which should then be burned by the hot exhaust fumes passing through.

In reality, city drive or any care about fuel economy will keep your RPMs too low for the heat to burn the particles, which will accumulate and even clog up the converter, as was the case in my car. In a future article, I’ll cover the symptoms of this problem and tell you how to solve it, but for now, let’s stick to the muffler and resonator.

3. Weight Reduction

Because the exhaust system is made to match the sound and power of the engine, it’s difficult to gauge how much of a weight reduction you’ll get by removing some of the components.

On a 2016 Ford Mustang, the muffler weighs up to 45 pounds while the resonator weighs 25 pounds. When you consider the weight of the steel pipe that has to replace the section where the muffler or resonator used to be, weight loss is negligible.

The only proper way of reducing the weight of the exhaust system is to swap to an aluminum straight pipe or an aftermarket high-performance replacement. It may cost a lot, but it’s worth it if you’re trying to lose as much weight as possible.

4. Legal Issues

It’s difficult to say with certainty whether removing the resonator or the muffler is illegal – it’s left to the states to sort out locally. If you take a look at this map, it appears that muffler delete is seemingly illegal state-wide. As for the resonator, I haven’t found any confirming information, but I would say it poses less of a legal issue.

Generally speaking, muffler delete is illegal, while resonator delete may not be. Check local regulations to know the exact extent of limitations.

5. Fuel Economy

Unfortunately, neither muffler delete nor the resonator delete provides any improvements in terms of fuel economy. If you’re seeking a method of lowering the fuel consumption of your vehicle, you should seek alternative means of achieving it.

5. Price to Delete

Because both the muffler and resonator require a similar amount of labor and a replacement pipe of roughly the same length, both will cost nearly the same to delete. You should expect the cost to be anywhere between $50 to $300, with most shops charging around $100.

Muffler Delete vs Resonator Delete – Which is Better

Exhaust modifications typically revolve around getting a better sound. Neither the muffler nor resonator affect fuel economy or horsepower and have a minor impact on the weight of the vehicle. They’re also priced similarly in terms of labor required to delete them.

So which one is better? In my opinion, a muffler delete is a far better option than getting rid of the resonator.

As muffler dampens the sound and makes it quieter, deleting it will give you a more aggressive and louder exhaust sound. The resonator may affect the volume slightly, but it has a more important role in keeping the resonating frequencies from creating annoying or unbearable noise.

Before you get your angle grinder and welding station, make sure to review the road regulations of your state. Most places have a ban on muffler deletes or straight pipes, and even make these vehicles illegal to sell, so do your research to avoid wasting time and money.

How to Delete Muffler or Resonator?

Deleting either the muffler or the resonator involves basically the same steps, so in this section, I’ll focus on the muffler. To get the job done, you’ll need a few things:

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The process involves a few steps:

  1. Lift the back of the car and place the jack stands underneath. Make absolutely sure the vehicle is properly secured before proceeding. I like to put cement blocks or shaped tree stumps as an additional layer of safety.
  2. The muffler rests on a couple of hangers, with pipes held together with clamps. Use the WD-40 on nuts and then unscrew them with the socket wrench.
  3. Use the rubber mallet to force the pipes to separate.
  4. Once the muffler has been disconnected, you can pull it slightly and get it off the vehicle.

Because the muffler is very heavy to control from the position you’re working in, you can use a jack stand to brace the muffler while you’re working on it or have someone assist you with the task. Just be careful not to drop it on yourself.

The next part involves plotting out the path for the replacement pipe and getting it fabricated. Because the new pipe also needs to be welded, I recommend leaving this part of the process to a professional – with the work you’ve done, you’ve already significantly reduced the cost of labor, so it’s worth it to let someone else finish the job. The following video has a nice overview of how the task is done.

Summary

The choice between the muffler or resonator delete is straightforward – if you can get away with it, delete the muffler and keep the resonator. You’ll reduce the weight of the vehicle slightly, and get a much better sound coming out the back!