The BMW M340i (G20) is, without a doubt, a phenomenal machine straight from the factory. Its B58 turbocharged engine is a modern masterpiece of power and efficiency, delivering a driving experience that blurs the line between a daily driver and a true performance sedan. But for the dedicated enthusiast, "phenomenal" is just a starting point. We believe in personalizing that experience—making it faster, louder, and undeniably ours.
The challenge? Doing so without voiding the factory warranty or committing to aggressive, permanent modifications like ECU tuning.
Enter HPS Performance. In this article, we take our stock 2024 BMW M340i 3.0L turbocharged B58 and transform it using a curated selection of straightforward, high-quality, and completely reversible bolt-on parts. We’ll show you how to unlock valuable horsepower and torque—thanks to essential upgrades like our HPS Air Intake and Charge Pipe Kits—while simultaneously enhancing the vehicle’s overall visual appeal by adding elements such as a carbon fiber wing and upgrading to a set of Rays 5spoke race wheels.
If you're looking to see how you can achieve dyno-proven power gains, a more aggressive induction sound, and a custom engine bay aesthetic—all tied together with upgraded wheels, suspension, and a vented hood—you’re in the right place. Follow along as we show you how you can turn an already great German sport sedan into an uncompromised, head-turning pocket rocket.
Heads Under the Hood
One of the most important parts of product development is 3D scanning. We utilized our advanced Creaform 3D scanner to generate a digital map of the entire engine bay. This crucial, non-contact process captures every contour, mounting point, and clearance limitation, allowing our team to work in an incredibly accurate virtual environment.
Using this data, we meticulously designed each of our flagship components. We engineered the HPS air intake kit for maximum airflow efficiency and sound, the charge pipe for enhanced durability and throttle response, and the high-grade, Cerakote-coated turbo heat shield to effectively manage heat soak while adding a subtle but customized aesthetic under the hood. This detailed, CAD-first approach ensured that every product—down to the final strut bars—is a true, direct bolt-on replacement, eliminating fitment issues and, most importantly, requiring zero permanent modifications or ECU tuning.
Design, Dyno, Delivery
The first component to receive the HPS engineering touch was the stock air intake system—a known point of restriction designed more for minimizing sound than maximizing performance. We engineered the HPS Air Intake Kit to be a direct, no-compromise replacement for the restrictive stock system. The core is a 3.5" mandrel-bent aluminum tube that guarantees the smoothest airflow path, resulting in dyno-proven gains of up to 11.3 HP and 11.8 lb-ft. of torque, instantly sharpening throttle response and acceleration.
The system features a wrinkle-black powder-coated steel heat shield with a lid that integrates with the factory duct to ensure the reusable, high-flow air filter only draws in cold air. For superior durability, we use 3-ply reinforced silicone couplers and a billet aluminum quick connect at the turbo inlet to eliminate a common failure point. All connections use custom embossed worm gear clamps with rolled edges, guaranteeing a leak-free seal that won't damage the silicone. Available in multiple finishes (including polished aluminum, red, blue, and wrinkle black) to enhance your engine bay aesthetic.
We then focused on a critical point of failure in the BMW M340i's turbocharged engine: the stock charge pipe. Our solution is a 3" aluminum charge pipe that is a robust replacement for the brittle factory plastic.
This design delivers an impressive increase of 4.6 HP and 7.3 lb-ft. of torque and ensures reliable performance even at elevated boost levels. Key features include bead-rolled piping, a billet aluminum quick connect to the intercooler, and a convenient 1/8" NPT bung for future performance mods like water-methanol injection. Like the intake, it uses stainless steel embossed hose clamps for a secure, leak-free connection, all packaged in a finish (like polished aluminum) that perfectly complements the HPS intake.
Maximum Coverage for Minimum Heat Soak
To effectively address the inadequate factory heat shield on the M340i, which allows excessive turbo heat to compromise performance, we engineered a superior solution.
The HPS Cerakoted Steel Turbo Heat Shield is constructed from heavy-duty steel for robust durability and is treated with a Cerakote ceramic coating. This advanced coating significantly improves heat rejection characteristics, ensuring the shield itself doesn't cause heat-soak.
The most critical upgrade is the shield's superior coverage. Our streamlined, one-piece bolt-on unit provides more than double the surface area compared to the factory shield 144.29 sq. in. vs. 67.77 sq. in. By blocking significantly more radiant turbo heat, the shield's core function is to maintain cooler Intake Air Temperatures (IATs). Cooler IATs prevent the ECU from automatically reducing boost, ensuring the engine can consistently operate at its peak performance level, especially during spirited driving.
The unit is a straightforward direct bolt-on replacement and includes all necessary stainless steel hardware. The combination of robust Cerakoted steel, enhanced thermal performance, and a clean aesthetic makes this heat shield an essential upgrade for maintaining optimal B58 power and engine efficiency.
Tightening Down the Turns
The fourth product that our team engineered is the HPS two-piece strut bar that ensures both a perfect fit and high performance tolerance. The design process was meticulous, centered around a 3D map of the engine bay. This detailed digital model allowed our team to precisely plot the strut bar's geometry, ensuring maximum clearance around vital engine components and a seamless installation. The strut bars themselves are CNC machined from two solid blocks of 6061 aluminum and feature a substantial 12mm thickness for superior rigidity. All necessary installation components are included, consisting of high-quality stainless steel hardware. To complete the aesthetic, the HPS logo and design elements are also precision CNC machined into the bars.
This HPS strut bar provides significant performance benefits, making it an excellent upgrade for the M340i, whether used as a daily driver or a track-ready sports car. By connecting the top of the two front strut towers to the radiator support, the bar increases chassis rigidity in the engine bay.
The added stiffness helps reduce chassis flex during cornering, leading to a more stable and predictable steering response. This translates to a more connected and enjoyable driving experience even during routine commuting and spirited driving on public roads.
On the track, where the car is pushed to its limits, the strut bar truly shines. It helps maintain the suspension geometry under hard cornering loads, ensuring the tires remain properly planted and maximizing the contact patch. This results in improved handling, better turn-in, and reduced body roll, allowing the driver to confidently push harder and achieve faster lap times.
Preventing a Failure Point
The factory coolant bleeder screw on many BMW models is an infamous weak point—a tiny component with the potential for catastrophic failure. Exposure to relentless heat cycles causes the plastic to become brittle and prone to cracking, even under normal driving conditions. For this reason, our existing HPS Titanium Coolant Bleeder Screw is a small but mighty upgrade: a relatively inexpensive, preventative measure that ensures the reliability of your entire cooling system.
The plastic is known to crack spontaneously, or more likely, to disintegrate in the housing whenever you need to remove it for a simple coolant flush or repair. To combat this critical vulnerability, we precision CNC machine our replacement from Grade 5 aerospace titanium, a material guaranteed never to fail under the cooling system's extreme heat and pressure. This titanium screw is coupled with a chemical-resistant Viton O-ring for a superior seal, ensuring longevity and durability, which provides peace of mind for daily commuting and track days alike. To improve ease of service, we designed the screw with a 4mm Allen head, eliminating the awkward large crosshead found on the original design that’s prone to stripping.
Elevating the Exterior
With the BMW M340i's engine performance and durability projects well underway, our team turned their focus to the exterior, aiming to craft a look that matched the car's aggressive new capabilities. The goal was to transform the vehicle into a cohesive, high-performance daily driver with bespoke styling—a street-legal, track-ready sports sedan. To bring this vision to life, HPS partnered with several leading brands in the aftermarket industry, starting with the car's posture and handling. A KW V3 coilover kit was installed, providing the necessary adjustability for both rebound and compression dampening via its dual level valves. This new lowered stance was beautifully complemented by a striking set of 19-inch Rays 57CR 5spoke wheels finished in Gunblue 2. To ensure maximum grip and stability in all conditions, the larger, wider wheels were wrapped in high-performance Toyo Tires Proxes Sport A/S tires, sized 245/35/19 in the front and 275/30/19 in the rear. For ease of installation, our team opted to add a 14x1.25 to 14x1.5 stud conversion kit to mount the wheels and secure them with Muteki HR50 14x1.5 lug nuts.
The cosmetic transformation was completed with sleek Suvneer aero components, including the CS Designed Aluminum Hood, MP Designed G20 Carbon Fiber Side Skirt Extensions, G20 LCI SM Carbon Fiber Front Lip, and carbon fiber side mirror covers. A standout choice was the R1 Designed Carbon Fiber Trunk Spoiler, selected specifically because it combines aggressive aesthetics with lightweight performance.
Inside, the M340i received performance and safety upgrades with high-performance Sparco QRT Performance racing seats, finished in leather to match the car's interior. These seats were installed using Sparco’s slider bracket and side mounts, complemented by Sparco COMP H-2 PD 6PT 2" harnesses for track security. Small, but impactful interior details included carbon fiber steering wheel shifter paddles, chosen for their length over stock to offer better reach and comfort.
Finally, the team ensured a clean, intentional look by keeping the car's graphics minimal but impactful, designed by our friend Young Tea to complement the car's sleek lines and the Gunblue 2 wheels, completing the transition into a truly bespoke machine that embodies engineering excellence and aggressive style.
Beefed Up Street Build
By developing a comprehensive suite of upgrades, our team enhanced every aspect of the vehicle, from the engine bay to the exterior styling. Our in-house developed Intake Kit, Charge Pipe Kit, and Strut Bar drastically improve airflow, boost response, and chassis rigidity. Crucially, we also addressed common vulnerabilities in the M340i platform, such as finding effective solutions for mitigating ambient turbo heat and replacing the problematic plastic coolant bleeder screw with a durable alternative. The aggressive stance and bespoke look—achieved through KW coilovers, Rays wheels, and Suvneer aero—ensure this sedan is as striking visually as it is potent mechanically. The finished M340i is a testament to the quality and engineering excellence HPS strives for.
One of the most significant advantages of the entire HPS upgrade path is the absolute reversibility of every component installed. We deliberately engineered all performance parts and cosmetic enhancements to be a direct, bolt-on replacement for the factory equipment. This means no tuning is required for the performance parts, and no permanent modifications are made to the vehicle itself. This is a massive benefit for M340i owners who value flexibility, need to comply with specific inspection or warranty requirements, or simply enjoy customizing their car often. Every HPS upgrade can be completely removed, allowing the car to be returned to its stock configuration quickly and easily, giving owners the freedom to adapt their vehicle as their needs and tastes evolve.