Few aftermarket car upgrades are as convincing as a performance exhaust. Swapping the factory system with wider and straighter performance systems helps deal with the restricted airflow, multiple bends, and subpar builds in mass-produced cars, or the main factors robbing the engine of its full potential. And they have the chops to transform everyday, runaround hatchbacks and sedans into unassuming sleeper cars.
Standard vs Performance Exhaust Systems
A performance or race exhaust is tuned to increase exhaust velocity and reduce restrictions and backpressure. In other words, it has been specifically engineered to boost power.
Today’s cars are burdened by design and space limitations, cost-cutting measures, various emissions and noise regulations that have all but killed driving fun. Stock exhaust piping winds its way from the manifold to the tips in multiple bends, includes parts that mute engine roar (think pops, bangs, and gurgles), and is made of narrow, thin-walled mild steel.
This hurts the engine in more ways than one. The narrow, snaking piping causes the pooling of spent gases or backpressure that impedes the next combustion cycle. And without combusting air and fuel, the engine doesn’t produce power to push pistons and conrods and turn the crank.
What’s more, the crush-bent mild steel pipes are easily deformed on impact (potholes, rocks, speed bumps), further restricting exhaust gases on their way out with multiple choke points or ruptures. And let’s not forget the eyesore that is rusted or stained exhaust pipes, putting a blemish on your car.
Basic performance exhausts include wider downpipes and headers, straighter mid and tailpipe layouts, fewer restrictive parts and cleaner, more robust builds. Stainless steel is the entry-level metal that meets the strength requirements (heat and impact resistance) in engines that produce more power.
The material is also mandrel-bent to ensure it remains at a uniform diameter throughout its length (to aid flow) and prevent kinking or ruptures when hitting road obstacles or coming in contact with water. The metal can be mixed and matched with engineered metals and alloys (titanium and Inconel, among others) to increase strength and shed some weight for racing applications.
In short, a race exhaust optimises exhaust flow out of the car, boosts engine power with fewer restrictive parts, and lasts longer. Paired with an equally capable air intake, this is the first upgrade car enthusiasts consider before they spend serious cash on racing cams, strengthened cranks, high-pressure injectors or bigger and faster-spooling turbos.
What’s Right for Your Car?
Buyers can go two routes – choose preassembled ‘complete’ systems, or use separate parts to meet specific performance needs. Exhaust completes come in three basic types:
- Axle-back systems – with new parts from the rear axle to the exhaust tips. This includes less restrictive mufflers and tailpipes, and imposing tip designs, finishes and colours. While power gains are negligible, the system is affordable, reduces weight, and aids airflow. A major benefit is the improved sound, with brands boasting proprietary tech to get a louder, deeper and raspier exhaust note.
- Cat-back/ GPF-back systems – these include replacement parts and piping from the catalytic converter or gasoline particle filter, with wider and straighter mid-pipes helping with exhaust velocity and preventing backpressure. Additional parts are straight-pipe mufflers, wider tailpipes and new tips. Choose this system for a balance between power, performance and value.
- Turbo-back – applicable for cars with factory turbos. This system includes downpipes with wider, revised designs for improved exhaust scavenging (pulsating air pressure that pushes spent gases out faster), combined with high-flow catalytic converters (again, to aid airflow), or cat-less exhausts for the same effect. The rest of the piping matches a cat-back and axle-back system. Turbo-back exhausts improve turbo performance, with higher volumes of cooled air for faster spooling, resulting in higher power and torque gains across a larger rev range. Similar header-back completes bring a big power boost in cars with aspirated engines.
Real-world Benefits
Consider investing in a racing exhaust if you appreciate:
- More horsepower: Full turbo-back and header systems can add 5 to 10 per cent more power. For cars averaging 200 hp, this means another 20 horses for faster acceleration and effortless overtaking, which is a substantial boost for racing and even more fun on the street.
- Wider torque band: Peak power and torque are available earlier in the rev range. This also extends to higher redlines, without the engine losing puff or having to change gears. The result is boosted in-gear or rolling speed and acceleration.
- Durability: Superior materials, advanced production methods, attention to detail (vibration-free brackets, seamless welds) and proven technology derived from competition racing are now available for everyday cars. This ensures exhausts last longer while delivering more driving fun.
- Sound profiles: They allow you to get the sound you want. This can vary from a quiet whirl to a deep, throaty sound. Sound profiles can also be changed for different engine loads and speeds. Again, the aim is to get you grinning when working the pedal.
- Customisation options: Car owners can choose exhaust completes or add different parts (downpipes, extractors, straight pipes, cat-less pipes, high-flow cats, and various muffler and resonator combos) either to the factory exhaust or part of different complete systems. There’s also the choice to go with different material finishes to get the look you want.
- Weight savings: Full, high-end titanium/Inconel systems shed around 20 kilos from the car’s total weight, which is a nice advantage off the starting line.
