Transform the sound and performance of your BMW B58 with our OPF decat downpipe with integrated heat shield. This premium upgrade is engineered for OPF and PPF models and delivers sharper throttle response, faster turbo spool, noticeable power gains and a deeper, more aggressive exhaust note. Built for enthusiasts who demand the best from their 3.0 B58 turbo engine, this stainless steel downpipe is a proven performance exhaust upgrade that unlocks the true character of your BMW or Supra.
Why choose this BMW B58 OPF decat downpipe
- Constructed from SS304 aircraft grade stainless steel, expertly TIG welded in house for strength, reliability and a perfect fit.
- Features a heat shield to manage under bonnet temperatures and protect surrounding components.
- 4.5 inch stainless steel decat downpipe body for maximum flow on OPF models.
- 3.5 inch stainless section straight out of the turbo for quicker spool and sharper throttle response.
- Mandrel bent for optimum gas flow and maximum internal diameter to deliver ultimate performance without sacrificing mid range torque.
- Lower exhaust gas temperatures and reduced backpressure relieve the turbocharger and increase cylinder charge.
- Substantial weight saving compared to the factory catalytic converter.
Real world gains you can feel
We have tested this product and found increases of around 20 to 25 bhp, alongside a noticeably more aggressive, motorsport inspired exhaust tone. Customer feedback has been excellent, praising the fit, finish and the transformation in sound and response.
Confirmed fitment for B58 OPF and PPF models
This downpipe will fit the following models with OPF and PPF only:
- BMW G20 and G21 M340i 3.0 285 kW 374 PS 2019 OPF model
- BMW G22 440i 3.0 285 kW 387 PS 2019 OPF model
- BMW G30 and G31 540i 3.0 250 kW 340 PS 2018 OPF model
- BMW G32 640i 3.0 250 kW 340 PS 2018 OPF model
- BMW G11 and G12 740i 3.0 240 kW 326 PS 2019 OPF model
- BMW G14, G15 and G16 840i 3.0 250 kW 340 PS 2019 OPF model
- BMW Z4 G29 M40i 3.0 250 kW 340 PS 2019 OPF model
- Toyota Supra MK5 A90 GR 3.0 250 kW 340 PS 2019 OPF model
Original BMW part number reference: 18329897313.
Installation and fitting support
Professional installation is recommended as exhaust tolerances can vary between cars, although feedback on this downpipe is that it is easy to fit. For fitting, we recommend Nforcd in Warwickshire. Request a quote at Sales@nforcd.com.
Important fitting notes
- Swap the gasket in the turbo end of the downpipe during installation. Not doing so can cause a fuel smell in the cabin.
- We recommend adding Lambda Sensor Spacer(s) to help prevent the engine management light in most cases. You will find these in our other items.
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