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©2018 Willow Performance

Willow Performance are excited to introduce our 4.0" Catless Downpipe for BMW N55 Engines. This will fit a range of different platforms with the N55 Engine, main ones being:

M135i, M235i, 335i and 435i. 


Please note this will NOT fit N55 engines built before July 2013. 


We chose 4.0" to avoid a step when going from the turbo to the downpipe in order to improve overall flow and decrease backpressure from turbulance caused if we used a 3.5". Our catless downpipe has been fitted to our M135i demo car and has not only vastly improved turbo spool, throttle responce, sound but is also allowing the turbo to perform in cooler conditions with less back pressure prolonging life. 


Expect gains of around 15hp from this one modification. This has been proven by multiple dyno's. This is truly a must have for N55 engines and really do wake them up. 


Please be aware that it can take up to 2-4 weeks for delivery if the item is out of stock. 

BMW N55 Decat Downpipe