Along with cold air intakes, exhaust systems are among the first upgrades in cars tuned for more power. This combination sets the stage for all subsequent modifications by ensuring the engine gets all the clean, oxygen-rich air needed for bigger bangs. Exhausts play a vital role in relieving the engine of spent gasses and allowing it to take its next breath. The faster and more efficiently this happens, the more power the engine produces. Though stock systems are generally adequate for everyday driving, they soon show their limitations.
Why Upgrade From Stock?
Cost-cutting and emissions regulations are the major reasons why stock exhausts don’t do your engine justice. The crush-bent mild steel might be cheaper and easier to produce but struggles at higher engine loads and the increased temperatures and pressures generated as RPMs rise. This leads to staining, rupturing and leaks and prevents proper exhaust flow.
Strict emissions and noise regulations have also led to narrower tubing with multiple bends and the addition of restrictive parts to filter out pollutants. This, however, slows airflow and causes major issues, such as increased backpressure and reduced exhaust velocity, preventing the engine from reaching its full potential. While good for daily driving tasks in mild weather, the factory exhaust won’t last long in spirited bouts on the highway, let alone more demanding track duty.
Benefits of Aftermarket Exhausts
Wider and straighter layouts, stronger materials and better builds are what you get when you order performance exhausts online. And this brings a long list of benefits to your car, among which:
- Increased power and torque – fewer restrictions, straighter layouts and bigger tubing means improved exhaust velocity. Spent gases exit faster, allowing the engine to take its next breath. This improved efficiency also results in higher power and torque numbers, with estimates of 10 per cent in full systems. Real-world benefits are improved throttle response, faster acceleration and a wider torque band for a punchier engine.
- Better sound – changing out stock mufflers and resonators with aftermarket exhausts fitted with extras like straight pipes and valving tech lets car owners fine-tune the sound. Deeper and louder sound can also be achieved with wide-diameter mid pipes and revised header designs. There are also options to quiet things down when choosing “quiet” muffler setups.
- Improved build and longevity – mandrel-bent stainless steel has higher tensile strength, is heat, impact and rust-resistant, and copes with higher temperatures and pressure in extreme engine loads.
- Eye-catching looks – milled, polished, matte or chrome finishes, the addition of carbon fibre or nickel alloys and seamless TIG welds makes for a combination that provides a cleaner and more appealing look, especially evident in the tips.
- Reduced weight – one reason to go aftermarket is the weight savings. Full systems can shed over 20 kilos, not an insignificant number if you’re after faster track times.
- Mix and match parts according to needs – there are endless customisation options with modular parts that can be mixed and matched to meet individual needs. Aftermarket parts can be bolted to existing tubing, or combined for even better results. Popular additions are X-pipes for improved flow and high-pitched sound, mufflers, resonators and collector tubes with wider diameter inlets, high-flow catalytic converters for better burns and reduced restrictions, and proprietary valving tech for a deeper exhaust note.
What to Look For?
When shopping for performance exhausts online, go with complete systems or separate parts that meet your needs. Axle-back systems replace factory parts from the rear axle to the tips. They’re the preferred exhaust upgrade if sound is your priority, with custom mufflers, resonators and proprietary valving systems bringing deeper, meatier sound. Hot dog resonators are a popular addition as they deal with irritating exhaust droning and coarseness without sacrificing volume.
The best balance between overall performance and price is from cat-back systems. These add wider mid-pipes to axle-back systems (the latter in single or split-pipe layouts) for even better sound, improved airflow and increased power. Most setups also lower fuel use in low to mid revs, with lower engine stress being another bonus.
For the biggest power gains, turn to header or turbo-back systems. These replace the entire stock piping, to include bespoke parts, ranging from redesigned header tubes and downpipes to catalytic deletes or straight pipes instead of restrictive mufflers. With specific layouts, like H-pipes for improved scavenging and low-end power or X-pipes for a cleaner sound and more high-rev push, you have the choice to mix and match different parts and get a sound that you like making this the go-to system.
To get more out of your purchase, consider established exhaust brands, quality builds, warranties and ensure that all parts are compatible with the vehicle. Buy all car parts and accessories, including exhausts from proven brands. Those with affiliations to official racing teams or builders supplying OE parts to performance car brands are a good place to start.
These have already put in the R&D, use advanced production methods, and won’t skimp on quality materials. Ensure the exhaust fits your car model and trim (get your VIN ready), is in the right width (including inlet and outlet tubes), has all the necessary mounting hardware, and comes with clearly defined warranty periods.