400HP SLEEPER PEUGEOT 309 GTI! Acceleration & Sound by turboandstance - October 12, 2025 This isn’t your average retro Peugeot… what started as a classic 1989 309 GTI has been transformed into one of the most savage old-school hot hatches we’ve ever featured. Under the bonnet is a 2.0 16-valve XU10 turbo engine from a Peugeot 406 Sri Turbo with forged internals, paired with a Mi16 head from a 405 Mi16, standalone ECU and a T34 turbocharger — producing over 400BHP while weighing just 875kg 🤯 In this video, we meet the owner behind the build, break down exactly how this insane setup came together, dive into the engineering and fabrication work, and finally take it out on the road to see how it performs in the real world 💨