Why This Aerospace Engineer Quit His Job to Tune BMWs

What does a B58 big-turbo build look like when an aerospace engineer takes over the calibration? We sit down with full-time calibrator Ryan Miller at Church Automotive Testing to break down the limits of the Gen 1 and Gen 2 B58 platforms. From dialing in a Motiv Reflex flying lead harness to sizing a Precision 6870 turbo and keeping a factory drivetrain together, we discuss the actual reality of building a high-horsepower street BMW. No theory—just real-world data log lessons from the shop floor. Chapters 00:00 - Quitting Aerospace to Tune Full-Time 01:31 - How to Actually Start Learning Calibration 03:33 - Engineering Theory vs. Real Dyno Practice 05:12 - Why Small Tuning Tables Lead to Deep Rabbit Holes 07:18 - Motiv Reflex: Flying Leads vs. Plug-and-Play 09:01 - Must-Have Sensors for Port Injection B58s 10:24 - Big Turbo Sizing: 6870 vs. 7275 Power Bands 12:17 - Drivetrain Betting: Axles vs. Transmission Survival 13:45 - The Best All-Time BMW (Sketchy 800HP 1-Series) 15:12 - B58 vs. S58: The True Bang-for-the-Buck King 🎯Hit that SUBSCRIBE button to stay up to date with my content! 📱 Connect with me on Social Media:   / nit3sh1ft     / nit3sh1ft