Pop, pop, pop! Why the 2024 GAC GS3 Emzoom GL's exhaust makes racy noises

The GAC GS3 Emzoom is quite possibly one of the most exciting models that will come to the Philippines this year.

The subcompact crossover will launch on June 30, 2023 with a starting price of under ₱1 million. It also has pricing and features that match and even beat the likes of the popular Geely Coolray.

But there’s one rather unique thing about this new Chinese crossover.

The top-spec GL variant will have a special exhaust system as standard. When you listen to it on YouTube, it makes popping and crackling noises when you let go of the throttle at high RPM.

We look into how this little GAC makes those sporty sounds and other ways that carmakers make their exhaust systems more exciting.

Sounds so good

A regular internal combustion engine produces power by detonating fuel and air inside its cylinders.

And the exhaust system, as the name suggests, extracts the gases from these multiple explosions and sends these into the air we breathe.

Most car owners are perfectly happy with having a stock exhaust that does its job as quietly and smoothly as possible. But there are benefits to upgrading to a performance exhaust.

The first is the added power, provided that the diameter and piping are correct for your engine. The second is more visceral – exciting noises.

This has its roots in motorsports – full racing cars often have straight pipes that have no silencers or resonators to help the engine produce maximum power (and maximum noise). However, this sometimes results in inefficient combustion, with unburnt fuel igniting in the exhaust system.

This not only leads to pops and crackles when the car is off-throttle at high RPM (called overrun), but can also produce huge flames. For car enthusiasts (and especially racing drivers like me), this spectacle is sweet music to our ears.

Bring the noise

Modern cars like the GAC GS3 Emzoom can produce these sounds through the engine computer unit (ECU).

When the driver hits a switch inside the car, the ECU will adjust the air-fuel ratio automatically so that you can hear all the pops and crackles on overrun.

Cars with aftermarket ECUs can also make racy noises through a “pops and bangs” tune. Again, a special computer map will alter the air-fuel ratio to make some unburnt fuel ignite.

But one major drawback of making your exhaust pop deliberately is that, if done improperly, it can cause serious long-term engine damage. 

Faking it?

Some manufacturers are doing away with changing the ECU mapping altogether to make their exhausts sound better – they just pipe fake noises through the speakers.

This is the case with cars like the latest Honda Civic Type R FL5. Despite being one of the most savage front-wheel-drive performance cars on sale today (with three tailpipes), it has a surprisingly tame exhaust sound.

But when the engine is put into R+ mode, it amplifies certain noises through the Bose audio system to make the occupants think that this super Honda has a super exhaust system. 

This technology has been controversial to many car enthusiasts as a form of deception. But others think it’s a great way to enjoy a racy exhaust without giving other people a headache.

What do you think about GAC’s decision to make its little crossover’s exhaust go pop?

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