Have you ever wanted to make your car sound like a rally monster that pops and crackles on deceleration?
Well, there are a few ways to increase the chances of your car’s exhaust popping loudly, and we’ll explore a few of them here. Don’t worry though – a tune is not the only way to get your car’s exhaust to pop and crackle.
What Causes Exhaust Popping?
First, what actually causes the popping sound? It’s the result of unburned fuel igniting in the hot exhaust system.
Now, contrary to popular belief, the popping sound can be created by both overly rich and overly lean conditions at higher RPM.
When the engine is running rich, it’s obviously using too much fuel and not all of it gets fully burned up during the combustion process. Most of the unburnt fuel then escapes through the exhaust valve and gets into the exhaust system, where it eventually ignites once it reaches an area with enough oxygen for combustion to occur. This causes the popping and crackling noise.
On the other hand, if the engine is running overly lean, then the combustion process takes up longer since a lean air-to-fuel mixture burns more slowly.
Because of that, combustion can still occur even when the exhaust valve is open during the exhaust stroke. The combustion then enters the exhaust system and creates a popping sound.
Lastly, exhaust popping can occur due to a delay in ignition timing – that’s how most anti-lag systems work and also how ECU tunes make cars start crackling and popping. By delaying or retarding the ignition timing, you can force the air-to-fuel mixture to combust when the exhaust valve is opening up and make the burning mixture enter the exhaust.
How To Get The Exhaust Popping Sound on Fuel Injected Cars
A. Get a Tune
Obviously, the easiest, best, and fastest way to make your car’s exhaust pop is to get a tune that has been specifically designed for it.
Modern fuel-injected cars are programmed and designed to reduce exhaust popping or crackle as much as possible in order to comply with regulations and make them as efficient as possible. Because of that, it is quite difficult to get a recently made car to pop and crackle.
With a tune, you will be able to override the stock ignition timing map and make your car pop and crackle whenever you want to, by simply pressing a button.
In addition to that, most tunes will also increase your throttle response and HP quite significantly, therefore if you have the money for it – go for the tune.
B. Do a Muffler or Resonator Delete
But what if you don’t have the money or simply don’t want to get a tune? Well, there are ways to get your car popping and crackling – especially if you have a more sport-oriented model, turbocharged engine, or a large displacement engine.
Now, the best way to make your exhaust pop and crackle without a tune is by doing a muffler or a resonator delete. This method worked really well for me on my Volvo S60 T5.
Not many people know this, but quite a bunch of cars do pop, crackle, and backfire all the time, but you just can’t hear it because of the resonator and the muffler.
That’s right, the muffler and the resonator combo completely eliminate the crackling and popping sound from your car’s exhaust, and all you have to do is remove either one of them to let your car crackle freely.
In my case, all I had to do was unbolt the stock muffler, slide it off the exhaust, and replace it with a piece of straight pipe. My car now crackles a lot when decelerating and pops really loudly if I rev the engine to 3000 RPM.
Be warned, though – a muffler delete is illegal in almost every state in the US and it can make your car sound really loud and annoying. Luckily, turbocharged cars surprisingly sound really good with a muffler or a resonator delete, as the turbocharger’s blades muffle the exhaust quite a bit.
C. Get a High Flow Catalytic Converter
Another good way to increase the chances of your car popping and crackling is by replacing your restrictive stock catalytic converter with a performance high flow one.
By getting rid of the restrictive stock catalytic converter, you allow your car’s engine to breathe better and also allow more oxygen to enter the exhaust. More oxygen means more chance that unburnt fuel will ignite inside the exhaust and cause a popping sound.
The biggest drawback of a high flow cat is that you might get a check engine light when you install it.
The thing is, the engine is constantly monitoring the efficiency of the catalytic converter with a second downstream O2 sensor. A lot of cars are really sensitive to even minor changes in catalytic converter efficiency, and swapping out the stock cat with a better flowing one can cause a check engine light.
D. Get Better Flowing Headers
If you want to make your car crackle even more, then you might want to consider getting better flowing headers. Just like with the catalytic converter, headers will allow your engine to breathe better and also increase the amount of oxygen that enters the exhaust.
Headers will also make your car sound a lot better, as they will eliminate the stock exhaust manifolds’ restrictions. In addition to that, they will also make your car’s engine a lot more efficient, as they will increase exhaust velocity.
The only drawback of headers is that they can be quite expensive – especially if you have a turbocharged or a supercharged engine. In addition to that, they can also be quite difficult to install.
E. Get a Cat-Back Exhaust System
A cat-back exhaust system is basically a muffler delete on steroids. Not only will it make your car sound a lot better, but it will also increase exhaust flow and increase the chances of your car popping and crackling.
A cat-back exhaust system will also make your car’s engine a lot more efficient, as it will increase exhaust velocity. The only drawback of a cat-back exhaust system is that it can be quite expensive.
How To Get The Exhaust Popping Sound on Carbureted Cars
If you have a carbureted car, then apart from doing a muffler delete, high-flow cat, headers, or a cat-back exhaust – one of the most common ways to get pops and crackles is by retarding ignition timing.
A. Retard Ignition Timing
Some carburated cars have electronic ignition control boxes, which cannot be tuned. If that’s the case for you, you might want to buy an aftermarket ignition control box that allows you to adjust ignition timing.
If you’ve got a distributor, then you can easily retard timing, but keep in mind that you will lose power by doing that.
B. Increase Pilot Jet Size
Another good way to make your carbureted car do popping and crackling sounds is by increasing the pilot jet size in your carburetors.
The pilot jet is what’s supplying fuel to your engine when it is idling and when the throttle plate is closed during deceleration.
Now, the original pilot jet is sized perfectly to reduce the chances of causing popping or crackling noises, but if you increase it just a bit, you will supply more fuel to the engine and significantly increase the chances of the engine producing those popping sounds when revving your engine.
So, there you have it – four ways to get your car’s exhaust popping and crackling.
Whether you go with a high-flow catalytic converter, headers, a cat-back exhaust system, or retarding ignition timing, your car will definitely sound a lot better.
Just keep in mind that these modifications can be quite expensive (especially the headers and cat-back exhaust system) and that they might not be street legal in your area.
If you’re looking for a cheap and easy way to make your car’s exhaust pop and crackle, then you might want to consider doing a muffler delete.
Do you have any other tips on how to get your car’s exhaust popping and crackling? Let us know in the comments below!
Eddie is the co-founder of CarCareCamp.com, and the site’s primary contributor.
Under his belt, Eddie has a bachelor’s degree in Automotive Electronics Engineering and almost a decade of experience working as a semi-truck technician (specializing in electrics).