While developing our 700S and 750R turbo packages for the 997TT, it became quite apparent that the stock exhaust manifolds were not up to the task of maximizing power output. However, it was also obvious to us that proper header development was more than just a matter of larger piping.
In order to equalize flow across all the cylinders, careful study of the available space was in order. Also in order to provide adequate road clearance while not taking any shortcuts with tubing arrangements, we painstakingly digitized the interface between cylinders heads and turbos and then CAD designed a primary and secondary tube solution that far exceeds in quality any other design currently on the market. This highly engineered approach also ensures fient that is unparalleled in the industry.
During chassis dyno testing, we experimented with different tubing diameters, and zeroed in on 1 5/8 inch primaries for an excellent balance of quick turbo spool up and massive high rpm flow. Larger diameters proved to seriously harm low end power and turbo spool characteristics. We also experimented with various heat barriers and coatings, but in the end could not make a case for them on this car.
Extensive data logging and track testing also exposed the need to use 321 grade stainless steel to ensure long reliability of header assemblies. These are the only 321 stainless headers available for the 997TT. Further, our headers are TIG Purge welded in house to ensure the strongest of weld joints and the smoothest of internal flow. We're so confident of our headers to withstand the extreme temperatures seen in turbo charged power production, that we offer a lifetime warranty to the original purchaser.
As with all AWE Tuning exhaust products, each TIG weld is hand finished internally, only butt-welded junctions are used, and flange openings are size matched to their ports, all to produce the smoothest flow possible. It is this intensive attention to detail that sets AWE Tuning exhaust products heads and shoulders above the rest.