Advanced Tuning Products, Inc. (ATP Turbo) is a company dedicated solely to turbocharging. Their goal is to engineer and manufacture turbocharging components that make sense. While turbocharging itself is not "new", many of the components that they create are of "fresh" ideas that come from applying the basic principles of process improvement and re-engineering to turbocharging systems. Adhering to these principles has helped them to design and re-design components for turbocharging, that are often more simplified, but function better, and are more reliable.

T31 (T3) turbine housing with 4 bolt outlet. Fits turbine wheel found on GT28RS, GT2876R (GT25/40R) and all GT2871R turbos. Turbine housing A/R is Garrett T3 .63, or .82 A/R. Turbine flow rating of .63 A/R T31 is comparable to T25 flanged .86 AR.