Borla Cat-Back Exhaust System — E90/E92 335i

At the heart of the system is Borla's patented straight-through multi-core technology, which eliminates the restrictive baffling found in OEM exhausts and reduces backpressure to unlock horsepower and torque that the factory tune left on the table. Ultra-smooth mandrel bends throughout the 2.5-inch piping diameter preserve exhaust velocity rather than disrupting it, and the split rear exit configuration keeps flow balanced across the RPM range — contributing to a more immediate throttle response and real-world fuel efficiency gains on your daily commute.

Installation is a straightforward bolt-on affair. No cutting, no welding, no fabrication — the system uses existing mounting points and hardware for a clean, professional result whether you're doing it yourself or having a shop handle it. Out back, a 3.5-inch round rolled angle-cut tip finishes the install with a purposeful, understated look that complements the E9x body lines without going over the top.

Then there's the sound. Borla's tonal signature is genuinely difficult to replicate — deep and authoritative at wide-open throttle, but composed and drone-free during highway cruising. It's the kind of exhaust note that rewards spirited driving without making a 45-minute commute miserable. Every system ships with Borla's industry-leading million-mile warranty, making this one of the most confident long-term investments you can make in your 335i.