Evolution Racewerks ER BMW B58 F and G Chassis 4.5 inch Catless Downpipe for M340i and M340ix Non OPF Models
Unlock serious performance from your BMW B58 with the Evolution Racewerks Competition Series 4.5 inch catless downpipe. Designed for F and G chassis B58 cars including the G20 M340i and M340ix that are not OPF equipped, this ER downpipe transforms throttle response, reduces turbo lag and lets your turbo breathe for stronger, earlier torque and higher peak power. Built from premium 304 stainless steel with precision CNC V-band flanges and beautiful TIG welds, it is engineered to fit your OEM or aftermarket exhaust system and deliver track-proven durability.
Searching for BMW B58 downpipe, M340i downpipe, G20 M340i decat downpipe, F30 340i downpipe, M140i downpipe, M240i downpipe, 440i downpipe, 540i downpipe, Z4 M40i downpipe, X3 M40i downpipe or B58 catless downpipe UK? This Evolution Racewerks 4.5 inch catless downpipe is the go-to upgrade for maximum flow, faster spool and an aggressive exhaust note. We run this setup on builds here at Nforcd and customers have been consistently delighted with the fitment quality, performance gains and sound.
Optional thermal coated black finish available
Why a 4.5 inch B58 downpipe
The B58 turbocharger uses a larger 4.5 inch outlet. ER engineered a matching 4.5 inch CNC machined V-band inlet and long, smooth transitions to prevent turbulence and backpressure right at the turbine exit. This preserves exhaust gas velocity, improves turbo efficiency and reduces lag. Compared to restrictive factory catalyst honeycomb, the free-flowing 4.5 inch catless design lets the turbo spool faster and pull harder through the entire rev range. Manufacturer testing shows gains across the powerband with a noticeable left-shift in the curve for earlier torque delivery.
Key features
- Direct fit for BMW B58 engines across F and G chassis including G20 M340i and M340ix non OPF models
- 4.5 inch mandrel bent primary for maximum flow, smooth long transitions to downstream exhaust
- Higher maximum horsepower and a stronger, earlier torque curve
- Faster turbo spool and sharper throttle response
- 100 percent 304 stainless steel construction, 100 percent TIG welded
- Precision CNC machined billet stainless turbo V-band flange
- O2 sensor located in the factory position for clean integration
- Compatible with factory exhaust and aftermarket cat-back systems
- Available finishes: brushed, optional polished, optional high temperature black thermal coating
- Optional extra wideband O2 bung and optional EGT bung, both supplied with pre-installed plugs
- Track tested durability with all required hardware included
- Limited Lifetime Warranty
- Built in the USA
Brushed finish shown
Thermal coating option
The ceramic thermal coating keeps exhaust heat inside the downpipe to lower under-bonnet temperatures and maintain gas velocity for reduced backpressure. ER’s coating resists up to 2000°F and adds extra corrosion protection. Available in black.
CNC machined billet stainless V-band flange for the B58 turbo
Compatibility and fitment
This ER Competition Series 4.5 inch catless downpipe fits the following BMW B58 petrol turbo models that are non OPF equipped:
- BMW 1 Series: 2016+ F20 F21 B58 M140i and M140ix
- BMW 2 Series: 2016+ F22 F23 B58 M240i and M240ix
- BMW 3 Series: 2016+ F30 F31 F34 GT B58 340i and 340ix
- BMW 3 Series: 2019+ G20 B58 M340i and M340ix non OPF
- BMW 4 Series: 2016+ F32 F33 F36 B58 440i and 440ix
- BMW 5 Series: G30 540i
- BMW X Series: G01 X3 M40ix, G02 X4 M40ix, G05 X5 M40ix
- BMW Z Series: G29 Z4 M40i
If your car is OPF equipped, please select the Supersprint Catless Downpipe instead.
Fitting and support
Professional installation recommended. For fitting at Nforcd in Warwickshire or to request a fitted price, email Sales@nforcd.com. We have extensive experience with BMW B58 downpipes and can advise on the best setup for your build.
Part numbers
- BM-EXH018S
- BM-EXH018P
- BM-EXH018TB
Important usage notice
For off road competition use only. Not legal for use on pollution controlled vehicles on public roads or highways. Not for sale, installation or use on licensed vehicles in the state of California. A vehicle compliance waiver may be required.
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