Universal Adjustable Turbo Boost Controller 1-30PSI - Manual Closed Loop Turbocharger for Car Modifications - Perfect for Performance Tuning & Racing Applications

I hooked it up to pressure-regulated air, and tried to set a 20-25psi “opening point”. Not even close.Took it apart, stretched the tiny spring. Still not close.Added a second spring. Closer, but unreliable.Bought a $30 one (with click-stop adjustment; accurate and consistent), and wow! A quality part that was far more adjustable and did what it said. More importantly, wow! What a change in performance.Avoid this product. Save your time and money and spend a little more to get a lot more.