Competition Series 4" Catless Downpipe for the N26 (4 Cylinder) Engine e91 Because low back-pressure and high

Because low back-pressure and high velocities allow the turbocharger to spin faster

Plenty of days

it will still be a question people will ask and the simple answer is on average

When intake air starts to reach the speed of sound (Mach 1) the piping size itself becomes a restriction (and yes

This expansion disrupts internal flow and causes turbulence

Competition Series 4" Catless Downpipe for the N26 (4 Cylinder) Engine e91 Because low back-pressure and highIntroducing our new Competition Series 4" Downpipes for your N26 four cylinder turbo engine! Fits all 2012+ 328i, 320i, 428i, 420i, 228i with the N26 engine (does not fit N20 engine). We've made a simple guide to help you tell which engine you have in your car. Click Here: How to tell if you have an N20 or N26 Engine. Key Features: Made in the USA! Manufactured in house. Now available for the 2012+ BMW 328i 320i 428i 420i 228i N26 Engines! Horsepower