This example is the popular Killer B Motorsport 321 Stainless Steel 2-bolt Holy Header. This header and/or exhaust manifold is a great way to increase the exhaust flow due to the smooth bends in the design that will optimize the exhaust flow. This will help maximize the flow potential of your turbocharger which will also reduce the spool time. This is an equal-length design that will produce an aggressive exhaust note while improving the performance and response throughout the entire RPM band.
DETAILS:
CAST COLLECTOR: The collector is made of thick-walled cast 347 stainless. This design removes several welds which removes flow disruption for less turbulence. This also allows the collector to be designed as a true high-velocity merge.
SHORT EQUAL LENGTH PRIMARIES: Shorter length primaries make for an equal length header which means less header volume and quick spool up.
SYMMETRICAL PRIMARY DESIGN: A similar tube length and bend geometry keeps the pulse velocities high and consistent when compared to equal length headers with different non-symmetrical primary tubing geometry.
SMOOTH MANDREL BENDS: All the bends utilize a mandrel to promote non-restrictive flow, and Killer B uses the largest bends possible at every location.
THICK WALLED 321 STAINLESS STEEL CONSTRUCTION: 321 is alloyed with titanium which not only costs more but it is ideal to handle the elements of extreme heat found in the turbocharger. With that being said, the turbocharger will create heat that will surpass the limits of 304 stainless steel, and 321 is more robust to promote longer life.
2-BOLT UP PIPE CONNECTION: Allows for connection of 2-bolt flange style up-pipe connection
Weighs 17lbs
Works with OEM EJ25 oil pans along with the Killer B Motorsport Performance Aluminum Oil Pan
Made in the USA
NOTE:
May not fit some Forester, Outback, and Legacy models with the OEM oil pan and cooler