QHCE M340i / M440i Catback — G20 / G22 (B58)
QHCE M340i / M440i Catback — G20 / G22 (B58)
VALVETRONIC
Whisper to wide‑open.
Valves shut, it’s refined enough for a 6 a.m. start. Valves open, it roars. Flip the valves and hold the throttle — feel it climb.
Verify fitment with your vehicle
Confirm this kit is engineered for your exact car before checkout.
The M340i and M440i G20/G22 with the B58 already sound great. We just take the volume and personality up a few notches without breaking the OEM character.
FITMENT
| Chassis | G20 (M340i sedan), G22 (M440i coupe), G23 (cab) |
|---|---|
| Years | 2019 – 2024 |
| Engine | B58B30M1 — 3.0L inline-six turbo, 382 hp |
| Trims | M340i / M340i xDrive / M440i / M440i xDrive |
| Mid-pipe flange | OEM 3-bolt — direct bolt-on |
SOUND PROFILE
B58 in M-trim cars already does a real exhaust note. Closed: barely louder than stock at idle, smoother cruise. Open: snarling six-cylinder voice, crackle on lift, hard pops on every up-shift in Sport+.
Measured at 50 ft, idle, ambient temp. Highway WOT 5-10 dB higher.
MATERIAL SPECS
- Pipes: 304 stainless steel, 1.5mm wall thickness
- Welds: TIG-welded, back-purged for OEM-grade finish
- Muffler chamber: Multi-stage with electronic valve actuator
- Tips: Carbon fiber wrapped, 304 stainless inner, QHCE laser-engraved
- Heat shielding: Spot-welded stainless wrap on the muffler section
WHAT’S IN THE BOX
- Full catback assembly (mid-pipe + muffler + tailpipes)
- Pre-installed electronic valve actuators
- Wireless remote (glovebox-friendly fob)
- Key-chain switch (keyring-sized)
- In-cabin controller (3M-mountable)
- All OEM-spec hardware + gaskets + clamps
- Printed installation guide (also linked digitally)
INSTALLATION
2-3 hours in a home garage with a floor jack and stands. 45 minutes on a lift. Standard hand tools — no welding, no cutting, no tuning. New gaskets and OEM-spec clamps are included in the kit.
SHIPPING & LEAD TIME
| Production | ~7 business days — every kit is built-to-order, TIG-welded and QC'd before it leaves the floor. |
|---|---|
| Freight | 4–5 business days, continental US, fully insured + tracked. |
| Total time to door | Roughly 2.5 weeks from checkout to delivery. |
| Shipping cost | Free on orders $1,000+ in the continental US. AK / HI / international quoted at checkout. |
| Notes | You'll get a tracking number the moment the kit ships. Any production delays are flagged in writing the same day. |
WARRANTY
Lifetime structural warranty on the pipes — cracks, weld failures, rust-through, we cover it. 2 years on the electronic valve actuators and remote system. 90 days on cosmetic finish (carbon fiber tips and laser engraving).
For off-road / track use only. Not legal for highway use in all 50 states. Buyer assumes responsibility for compliance with local emissions and noise regulations.
PRODUCTION
Built-to-order, TIG-welded, QC'd before freight.
FREIGHT
Continental US. Fully insured + tracked.
FREE SHIPPING
Continental US orders over $1,000.
STRUCTURAL WARRANTY
Lifetime on pipes · 2 yr on electronics.
BUILT TO ORDER
ORDER TODAY. HERE'S YOUR TIMELINE.
BUILD SLOT RESERVED
Order locked. Your kit enters the fabrication queue same day.
FABRICATION COMPLETE
TIG-welded, leak-tested, QC'd, crated. ~7 business days.
FREIGHT
Insured + tracked across the continental US.
AT YOUR DOOR
Bolt-on install, no tune. First cold start that afternoon.
Dates computed live from today against the standard 7-day build + 4–5 day freight window. You get an email at every step.
WHAT'S IN THE BOX
EVERY KIT INCLUDES
- 01
FULL CATBACK SYSTEM
Mid-pipe, valved muffler, and tailpipes. Direct OEM flange fitment.
- 02
ELECTRONIC VALVE + ACTUATOR
Pre-installed and wired. Just plug into the included controller harness.
- 03
WIRELESS REMOTE
Glovebox-friendly fob. Open / close / auto.
- 04
KEY-CHAIN SWITCH
Smaller fob you can leave on the keyring.
- 05
IN-CABIN CONTROLLER
3M-mount it on the trim. Toggle from the driver's seat.
- 06
QHCE-LASERED CARBON FIBER TIPS
4-out tips with a subtle QHCE logo laser-engraved on the inside.
THE BADGE TAX, ITEMIZED
SAME ARCHITECTURE.
NONE OF THE MARKUP.
You're not paying less because it's worse. You're paying less because there's no importer, distributor, dealer, and ad budget between you and the workshop.
| QHCE | NAME-BRAND VALVED SYSTEMS | |
|---|---|---|
| This kit, delivered | $1,200.00 | $3,000 – $7,000+ |
| Electronic valve control | Remote + keyfob + cabin switch, included | Controller often sold separately |
| Construction | T304 stainless · carbon tips | T304 / titanium |
| Tune required | None — pure bolt-on | None |
| Structural warranty | Lifetime | 1–5 yr typical |
| Lead time | ~2.5 weeks, built to order | Frequently backordered |
Name-brand figures reflect typical published pricing and policies for electronically valved catback systems, mid-2026. Same valve architecture, same weld type — the savings come out of the middlemen, not the hardware.
