Thread: 4cyl Header Design 101

Header Design Part One

By Sarah Forst
*help from Mike Kojima

A header is one of the first bolt-on modifications most tuners undertake but there are many factors involved in how to choose the best header design for your ride. Let’s get into the detail behind header design and how to choose what will work for your ride! Part 1 of this article will discuss the components of a header and the materials used to manufacture them. Part 2 will go into detail on how a header makes power and what design will produce your desired powerband.



A stock cast iron exhaust manifold is designed for quick cat light off, clearance around the engine and low cost before power production



This AEBS header is a unique design as it merges the primary pipes from the cylinders adjacent in the firing order, yet it still makes decent horsepower.



This Nissan SR20DE header made by ASP features equal length primary tubes and 321 Stainless construction. It makes lots of power

part 1

part 2

BTCC golf with a tasty 4-2-1



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most street DE/VE headers ie eBay, SSAC, fuji, hotshot etc would appear to be paired wrong?
does length relate to pairing *sounds rude LOL

1&4 with 2&3




1&2 with 3&4



good little read

david