Unlock serious performance on your BMW B58 with this BMW 340i 440i B58 Downpipe featuring a Hi-Flow 200 Cell Sports Cat and integrated heat shield. This catted B58 downpipe is engineered for power, response and reliability, delivering the ideal exhaust upgrade for BMW M140i, M240i, 340i, 440i, 540i and 740i models with the B58 engine (pre-OPF).
Why choose this BMW B58 200 cell catted downpipe
- Manufactured from T-304 high-grade stainless steel and TIG welded in-house for strength and longevity.
- Mounts straight from the turbo to reduce restriction, increase turbo spool and sharpen throttle response.
- Hi-flow 200 cell sports catalytic converter for improved exhaust flow versus stock while maintaining emissions control.
- Integrated heat shield to help manage under-bonnet temperatures.
- Produces a more aggressive exhaust note with a deep, refined tone.
- Lowers temperatures and exhaust backpressure to relieve the turbocharger and increase cylinder charge for maximum performance.
- Finished in brushed stainless steel for a premium look and corrosion resistance.
Real-world gains
We have tested this product and found increases of around 20 to 25 bhp without tuning and 120 bhp+ on a tuned car. Customers consistently report faster turbo spool, improved mid-range punch and a great sportier sound. We have used and fitted this B58 catted downpipe on our own cars and customer builds with excellent results.
Compatibility / fitment
Fits the following BMW models with the B58 engine and pre-OPF:
- BMW M140i
- BMW M240i
- BMW 340i
- BMW 440i
- BMW 540i
- BMW 740i
If you are unsure whether your car is pre-OPF, contact us and we will be happy to help.
Emissions and legality
These should pass an MOT emissions test when fitted. They are road legal and Euro 5 rated.
Installation
Professional installation is recommended as some exhausts sit slightly different from others and can be tight. For fitting, we can help. Nforcd, based in Warwickshire, offers installation and setup. Request a quote at Sales@nforcd.com.
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