String Theory Garage will be closed to the public from Wednesday, 29th July to Thursday, 6th August for our annual shutdown.
If you need to get in touch, please leave us a voicemail or send an email. Our team will happily get back to you when we return on Friday, 7th August.
Shopping online? Don't worry! Our online store will remain active! We hope to ship orders placed for in-stock items as normal during the shutdown. Anything else will be dealt with upon our return.
Thank you for your understanding, String Theory Garage Team
Unleash the full acoustic potential of your BMW M140i (F20/F21 LCI) with this Milltek Sport Non-Resonated Cat-Back Race Exhaust System. Designed for non-OPF LCI models, this louder, non-resonated cat-back system removes the factory resonator for a more dramatic, uninhibited exhaust tone — perfect for track day use or drivers who want the maximum acoustic transformation from a cat-back upgrade.
A direct bolt-on replacement for the OEM cat-back section. Available in five tip finishes to suit your preference. Works with existing OEM downpipes and catalysts — no remapping required, though a Stage 2 tune will further unlock the M140i's performance. Manufactured from 304L stainless steel in the UK.
Fitment: BMW M140i F20 & F21 LCI (Non-OPF models)
Race product: Yes
Tip options: Polished, Cerakote Black, Titanium, Burnt Titanium, Carbon Fibre
