Akrapovič BMW M135i (F40) Slip-On Line Titanium Exhaust System

The Akrapovič Slip-On Line (Titanium) is a precision-engineered exhaust system that brings out the true character and performance of the BMW M135i F40. Crafted entirely from lightweight titanium, this system is designed to enhance every aspect of the driving experience, from sound and performance to weight savings and aesthetics. More than just an exhaust, it's the finishing touch this hot hatch deserves, how it should have come from the factory.

The Slip-On Line transforms the exhaust note entirely, delivering a smooth, refined tone at cruising speeds that opens up into a genuinely deeper, more purposeful growl under acceleration or when driven more dynamically. Akrapovič's engineers retained the factory dual-mode, ECU-controlled valve from the original system, letting you switch seamlessly between a civilised, comfortable character for daily driving and a genuinely sportier, more aggressive note when you want it, all without any unwanted drone creeping in during either mode. Complex components, including the valve housings and collectors, are cast in Akrapovič's own in-house titanium foundry, a level of manufacturing precision that's difficult to replicate with off-the-shelf mandrel-bent pipework.

Beyond the sound, titanium construction delivers a genuine weight saving over the factory steel exhaust, a real benefit for a front-wheel-drive hot hatch where every kilogram removed from the rear of the car has a measurable effect on handling balance and overall agility. The system is finished with hand-crafted carbon-fibre tailpipes, included as standard with this exhaust, giving the rear of the M135i a distinctive, purposeful look that signals exactly what's fitted underneath without being shouty about it.

Important installation note: fitting this system requires the stock exhaust to be cut, this is not a reversible bolt-on modification. Review Akrapovič's installation instructions carefully before starting, and if you're not confident doing this yourself, have it fitted by a workshop experienced with Akrapovič products.

Optional upgrades available: Akrapovič also offers a matching Evolution Link Pipe Set for this platform, which further deepens the exhaust note and adds additional weight savings when combined with this Slip-On Line, alongside an optional Sound Kit that lets you control the exhaust valves independently of the car's drive mode via a remote or smartphone app. Installing either of these optional upgrades will invalidate ECE type approval for the system as a whole, so it's worth deciding upfront whether outright road-legal compliance or maximum sound and performance matters more for your build.

Why Choose This Exhaust System

• Genuine titanium construction throughout, delivering real weight savings over the factory steel exhaust
• Retains the factory dual-mode, ECU-controlled valve, refined at cruise, aggressive on demand
• Includes hand-crafted carbon-fibre tailpipes as standard
• Valve housings and collectors cast in Akrapovič's own in-house titanium foundry
• No unwanted drone in either sound mode, genuinely refined engineering rather than just louder
• Compatible with the optional Evolution Link Pipe Set and Sound Kit for further customisation

Compatibility

• BMW M135i (F40)

Installation note: the stock exhaust system must be cut to install this Slip-On system, this is a permanent modification.