Revision 1.2 | Revised CUSTOM Exhaust Collector
Revision
Upgraded exhaust collector for improved flow
The exhaust collector for the EVOheader has probably been the most challenging component to produce. The original mission of fabricating a true bolt-on header for the 07K engine that actually worked and increased performance required a very very tight header design due to the limited space available. Although the exhaust primaries could somehow be routed in many different ways, a hard fact was that at some point, these 5 tubes would need to meet and transition into a single tube before meeting the exhaust downpipe. The required exhaust collector would need to be much shorter than anything available in the market, back then and even today. A design had to be drawn from scratch. Aside from its reduced height, this shallow design would also need to be gentle and smooth in its internal geometry to the traveling flow, thus minimizing any gas velocity losses. In 2008 a precision metal stamping shop specialized in high-end medical and aerospace components agreed to develop the tooling dies and handle limited production. The cost was very high, and kept creeping up through the years. It ultimately forced us to pause the production. The year was 2014. As a result of this situation, a new non-bolt-on version, or Gen 2 of the EVOheader was developed, one that utilized an off-the-shelf 5into1 exhaust collector. Being a much taller unit, the regular collector prevented the resulting header design from meeting the stock downpipe fixing point. This forced the need to offer a new bespoke downpipe section (with a high flow catalytic converter) along with the EVOheader Gen 2. They were sold as a package. Even though the performance increase remained intact, the community’s mixed reaction to this change, which eliminated the bolt-on feature and brought in an important cost increase (as more parts were required), was loud and clear. A few sets were sold while we worked at finding a new stamping supplier. In the meantime, the interest in the 07K engine started cooling down during those years. This was mostly attributed to the introduction and early popularity of the new 2.0 FSI turbo engines at the time. Eventually in 2021, a very strong new wave of interest and attention to the iconic 07K 2.5L engine motivated us to more decisively produce the critical exhaust collector. Our newly found vendor was able to produce the shallow exhaust collector much more efficiently and guaranteed quick turnaround times allowing us to reissue an improved version of the original bolt-on EVOheader. Through the years, the EVOheader remains a clear must-have when pursuing proven and solid performance gains for the venerable VW 07K 2.5L engine.
