BMW 335i 435i N55 Intercooler and Decat Downpipe Kit – FMIC and Catless Turbo Downpipe Upgrade for N55
Unlock reliable, repeatable power on your BMW N55 with this front mount intercooler and decat downpipe package. Designed for maximum cooling performance, faster turbo spool and a more aggressive exhaust note, this upgrade is ideal for spirited road driving and track use. We run this setup on our own N55 cars and customer feedback has been fantastic for power consistency and ease of fitment. Lifetime warranty included.
Compatible BMW N55 models
Direct plug-and-play fitment for the following N55-powered BMWs:
- BMW M135i July 2013 onwards
- BMW M235i July 2013 onwards
- BMW M2 all models
- BMW 335i July 2013 onwards
- BMW 435i July 2013 onwards
Note: The decat downpipe fits all N55 engines from July 2013 onwards. It will not fit the 135i pre-July 2013. We supply a version for earlier models in our other items.
Why upgrade the N55 intercooler and downpipe
- Lower intake air temperatures for consistent performance and safer running on tuned N55 engines
- Reduced exhaust backpressure for quicker turbo spool and sharper throttle response
- Noticeable power gains with improved midrange torque and a stronger top end
- More aggressive, authentic turbo six-cylinder exhaust note
Intercooler engineering and features
This BMW N55 front mount intercooler uses a high-efficiency bar-and-plate core paired with flowed cast end tanks to maximise charge air cooling and minimise pressure drop.
- Massive 5 inch competition core with flowed cast end tanks
- Four extra rows at the front to increase the external surface area
- Internal guide fin on the intake side to direct airflow through the top four extra cores
- Approx. 11.5 kg total weight
- Near 100% more internal volume and around 90% more external surface area vs. the standard intercooler
- Core dimensions: 520 mm x 210 mm x 130 mm (same overall dimensions as popular Wagner units)
- Direct-fit, plug-and-play installation; typical fitting time around 1–2 hours
Proven cooling results
Road-tested over five back-to-back pulls, both the stock intercooler and the upgraded core saw intercooler intake temperatures of approximately 135–140 degrees. At the outlet into the engine, the stock intercooler measured around 75–80 degrees, whereas the upgraded intercooler consistently delivered outlet temperatures in the high 20s over all five runs. The result is repeatable performance with less heat soak.
Decat downpipe specifications and benefits
- Machined from T304 high-grade stainless steel
- TIG welded in-house; fabricated in the UK
- Laser-cut flanges, 10–12 mm thickness for durability and perfect sealing
- Mandrel bent for superior gas flow and maximum internal diameter
- Sharper throttle response thanks to faster turbo spool
- Lower exhaust gas temperatures and reduced backpressure; improved cylinder charge
- Substantial weight saving versus the factory catalytic converter
Tested power increases of approximately 10–15 bhp have been observed with the decat downpipe.
Installation, fitting and support
- Direct-fit kit for listed N55 models; professional installation recommended
- Intercooler install typically 1–2 hours; downpipe fitment time can vary by vehicle
- We recommend using a Lambda (O2) Sensor Spacer to help prevent an engine light in most cases; available separately from us
- Want this fitted? Nforcd offers professional installation in Warwickshire. Request a fitting quote at Sales@nforcd.com
Warranty
This product comes with a lifetime warranty for peace of mind.
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