Ford Focus ST: How Performance Exhausts Can Maximise Power and Speed

Have a Focus ST and are looking for more performance? Factory options may be good for upgrading looks or increasing comfort on longer riders, but for sheer power your best bet is to go aftermarket. Besides tweaking the suspension with coilovers or air ride systems for crisper turns and more stability at high speeds, simple additions like exhausts free up the turbocharged engine and let it breathe. The car livens up when on the gas, accelerates faster and belts out a deeper, throatier tune from the tips.

Why Stock Exhausts Don’t Make the Cut?

Factory systems undergo cost-cutting measures and need to adhere to emissions regulations. Both factors hurt performance and longevity and to a larger extent go against what the ST is all about – pure driving pleasure. The crush-bent mild steel in narrow diameters and multiple bends doesn’t help with exhaust flow, creating pockets of backpressure in the piping and risking damage to engine internals and the tubing itself.

And the subpar materials are subjected to higher heat levels, increased impact and exposure to corrosion, meaning possible ruptures, power loss, and damaged exhaust piping. This all has a negative impact when working the pedal. To deal with the shortcomings in factory units, an aftermarket exhaust for Focus ST of quality brings dozens of benefits.

What Aftermarket Exhausts Mean for Your Focus

Aftermarket exhaust systems go with wider and straighter parts built to a higher standard, allowing gases to exit faster and preventing common issues like rusting, dents and rupturing. This helps efficiency, power and longevity. The engine can take its next breath, and gases don’t encounter restrictions along their path on their way out.

Systems are designed with the engine specifics in terms of layout and fuel type and fit the stock recesses housing the factory exhaust so also offer easy fitment. All this translates to:

• Higher torque and power numbers – turbocharged cars like the ST are about outright speed. With increased combustion efficiency, reduced backpressure and maximized scavenging (pressure waves that draw gases out of the combustion chamber), the turbocharged four-pot can muster higher power numbers and extended redlines and reach top speeds with seconds to spare. With performance Focus ST exhaust, there’s a better feel to the throttle, faster acceleration, and easier overtaking.
• Improved longevity – mandrel-bent stainless steel is the entry point to performance exhausts, but buyers can also source exotic materials like Inconel and carbon fibre for increased strength, higher impact, rust resistance and lower weight. Built this way, there’s a lower risk of deformation or damage.
• Lower fuel use – a more efficient engine uses less fuel. This is especially true at lower RPMs and when stuck in traffic.
• Better sound – better exhaust flow with fewer restrictions means a louder, deeper sound. This can be tuned with separate parts like bespoke downpipes, extractors, muffler and resonator combos and valving, while still meeting emissions regulations.
• Customization – different parts and exhaust configurations can additionally be mixed and matched to get the desired results. Complete systems come in axle-back, cat-back, and turbo-back layouts with varied results and in different price brackets. Go with a cat-back and turbo-back exhaust for Focus ST if you’re after more power and faster acceleration, or an axle-back system if sound is your priority. Moreover, parts like downpipes help with the turbos by pushing more air and reducing turbo lag. This also reduces intake temperatures allowing for colder air to further help with combustion.

Choosing What’s Right

Materials, build, exhaust widths, layouts and compatibility are the main buying factors.

Exhaust Materials and Build

Stainless steel is rust-resistant, strong, and impervious to dents. It handles higher exhaust gas temperatures at higher engine loads, preventing staining. The material is also lighter, shedding at least 20 pounds over mild steel from manifolds to tips. Cheaper systems may also include aluminized steel in the mufflers. While those at the other end of the pricing scale can see carbon fiber in the tips, and titanium or Inconel to further reduce weight. All parts are mandrel-bent to retain structural integrity and ensure a longer lifespan.

Sizing and Widths

Performance systems go wider. Downpipes are substantially bigger to draw out more spent gases, with the rest of the tubing and related parts like catalytic converters also seeing bigger waistlines. Most systems are either 2.5 or 3″ in diameter to help alleviate the effects of backpressure while still retaining enough puff for the turbo.

Layouts

Besides the typical configurations mentioned above, layouts can differ between single and dual exhausts with separate piping from the manifold, and varied designs like H and X mid pipes or single or dual mufflers. Tip designs and how they’re configured can also be customized for the styling you’re after. The goal is to improve airflow out of the engine and tune the sound. Other parts like straight tubes, baffles or catalytic deletes also help in this respect.

Compatibility

Exhaust manufacturers market different systems and parts for different vehicles and engines making purchasing and compatibility easier. Ensure to get your VIN ready. And that the aftermarket exhaust for your ST is also supplied with the right mounting hardware for easy installation.