The collector has a smooth low-turbulence merging junction for all of the primary tubes flow and has the tubes merge in the order that provides maximum separation between cylinders on the exhaust cycle and overlap in the firing order. This reduces the chances of reversion from a high-pressure exhaust pulse back-contaminating a cylinder on overlap.
Backpurging can increase the fatigue strength and crack resistance of a weld in a tube by as much as 50%. All welded junctions and merges are hand ported during the fabrication process to ensure perfectly smooth joints.
Having brand new fresh gaskets with your headers is very convenient and means you don’t have to source this stuff at the last minute when installing the headers. Porsche claims the gaskets are reusable, but in the words of Vektor Performance principal, “I never get a warm fuzzy feeling installing used gaskets, so we will include new gaskets with our product.”
We love the World Motorsports dyno for doing super accurate tests on Late Model cars with highly adaptive ECUs. The super high airflow and the ability to carefully control engine and intake air temperatures help us get consistent results quickly.
The World Motorsports dyno is also probably the best dyno in California for tuning for these reasons as well. We would recommend their facilities over any other in our area for serious testing and tuning work.