How to Make Your Diesel-Engined Car Sound Cool

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Incarstyle's Sound BoosterIncarstyle's Sound BoosterActive Sound BoosterStandard muffler versus Sound Booster MufflerActuator for Sound Booster Technology
Fake exhaust noise. The worst crime in the automotive world after fake vents, fake brake discs, fake performance badges, and fake turbo sounds. Okay, it is not that immoral, but why does it exist and can you do it yourself?
Fake exhaust notes are becoming a trend with carmakers recently. The trend started once sports cars became more and more silent as their platforms progressed. While customers who cared about cars with less road noise and improved ride comfort received what they desired, car enthusiasts started to frown upon the “silencing” of modern sports cars.

The downsizing trend and turbocharging for sporty cars also brought the noise level down, and regulations also made newer cars more silent than their old equivalents. So, carmakers decided that they could not strip enthusiasts of the sporty sound of performance engines when they bought a sports car, but did not want to get into trouble with the authorities. The solution? Augmented engine sound systems.

In the case of the F10 BMW M5, the sound system plays a high-quality exterior recording of the engine noise through the speakers. At the time, BMW explained that the driver could use the tone to shift by ear and to enjoy the car more. Eventually, other manufacturers developed similar systems.

The Volkswagen Group employs a different system. On the Volkswagen Golf GTI, GLi, and Beetle Turbo, a dedicated speaker placed near the throttle body generates a distinct intake sound. On the Porsche 911 and the Panamera GTS, a special “acoustic channel” is employed on the intake when the Sport button is pressed, and it amplifies the sounds of the intake as it draws air into the engine.

However, what about diesel engines? Well, they have not received too much attention from manufacturers. However, there are a few exceptions. In the case of Audi, an optional exhaust equipment called engine sound amplifier can be ordered or retrofitted to individual models. This brings a somewhat sporty sound to the TDI units of the carmaker. The bi-turbo V6 engines from the Ingolstadt brand have this as standard equipment, and it is called Audi Active Sound.

What about aftermarket applications? Good thing you asked, because there are a few solutions on the market. We're going to talk about specialized systems, not just conventional exhaust systems, so bear with us.

Since simply adding a sport exhaust system does not bring the desired effect on a diesel engine, customers who want a different sound for their cars must turn to specialized solutions. While some exhaust specialists have developed complete systems for diesel-engined vehicles, some interesting solutions have been designed for customers expecting more than just a loud exhaust.

We found several companies in Germany that provide such services. They deliver exhaust solutions for diesel-engined vehicles, which bring several operating modes for the exhaust system, all with "V8 sound."

One of the modes is the “normal,” or standard operating mode, which is in operation when the users do not want their vehicle to be any louder than a regular car. The other operating mode is activated either through dynamic driving conditions, or with the press of the switch that commands the car’s sport mode. Once this is done, the vehicle’s exhaust comes alive and makes a sportier sound.

A company called In car style developed a system called the V8 Sound Module. For the moment, the stainless steel sport exhaust system is available for all BMW models, but the company states that it is available for other brands on request. The system can work with both diesel and gasoline engines and is a complete solution for a more pleasing sound.

Unlike manufacturer-designed systems, the V8 Sound Module features a stainless steel exhaust with two mufflers. If you go upstream from the mufflers, you can notice an odd device that’s also made of stainless steel, but not connected to the actual exhaust flow. That is the Sound Module, which is a resonating chamber for the exhaust system that’s been designed to help mimic the sound of a V8 engine with electronic aid.

Judging by the videos posted by the tuner, the system works great even for diesel applications. The trick with such systems it that they can be deactivated for normal city driving, so your neighbors will not despise you if you fit one to your car.

Eberspächer is a German company that became an OEM supplier for the Volkswagen Group and has developed the Active Sound Exhaust system. Like the one mentioned above, it works through a particular electronic sound generator fitted to the exhaust system. The sound generator is electronically controlled so that it can work depending on engine speed and throttle application, and it can also be deactivated.

Curiously, the system was initially developed to make cars more silent, as engineers recorded sound waves in the exhaust of cars and devised a way to dampen them through the sound system. The initial intent of this technology was to make cars without conventional silencers to be quieter in operation with a system that has less back pressure, thus improving fuel economy.

Other companies like Sound booster and Maxhaust provide similar systems for their customers. All the above systems work in the same manner, using the electronic sound actuator described earlier on in this story, along with a control module.

One of these systems will cost you between €300 and €1,200 ($334-$1337), without installation. We must note that fitting a sound actuator might require welding and metal cutting on most vehicles, and the fitting time can take up to eight hours. Needless to say, this type of modifications to your car will most definitely void your warranty, so tread carefully before making a decision.

Furthermore, the system must be chosen with consideration, as legislation in some countries does not allow loud exhaust systems. However, the Active Sound Booster is designed to comply with most regulations, so potential customers just have to make an inquiry with specialized companies to find out if their vehicle is suitable for such a system and if it will comply with local legislation.

Incarstyle’s V8 Sound Generator on BMW 435d

Active Sound Booster on BMW 5 Series

BMW X5 50d F15 with Maxhaust Active Sound

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About the author: Sebastian Toma
Sebastian Toma profile photo

Sebastian's love for cars began at a young age. Little did he know that a career would emerge from this passion (and that it would not, sadly, involve being a professional racecar driver). In over fourteen years, he got behind the wheel of several hundred vehicles and in the offices of the most important car publications in his homeland.
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