510 HP Was Just the Beginning… Pressure Testing the 300 Series Part 2

Some people said the stock injectors were the limit… so in Part 2, we’re taking things up a notch. Welcome back to the Pressure Testing Series, where Just Autos puts the 300 Series LandCruiser through real R&D — no fluff, no shortcuts, just raw testing and data. In this episode, Matt swaps the factory injectors for a larger, high-flow set to see just how much extra horsepower and torque we can unlock. If we made 510 HP on stock injectors (with a little help from NOS)… 👉 what happens when we give the 300 Series the fuel it’s really been asking for? On the hub dyno, Matt pushes the Twin Turbo V6 harder than ever, testing power gains across Tow, Power, and Power+ tuning ranges — all while monitoring reliability, fuel delivery, exhaust temps, and how the new injectors change the engine’s behaviour. These tests are designed to educate, inform, and show the real limitations — and real potential — of the 300 Series platform. It also highlights why Just Autos calibrates every tune around drivability, reliability, and safe, usable power. As always, the Just Autos 5W30 oil and high-capacity sump are present for every test to ensure consistency across the entire series. 👇 Hit subscribe — Part 3 We test the new Sump for oil temperatures and pressures. Keep up to date on our social channels at FB:   / justautosmechanical   IG:   / justautosmechanical   TikTok:   / justautos   #JustAutos #TuningToyotas #DieselPerformance #300Series #DynoTuning #ECURemap #ExhaustUpgrade #TurboUpgrade #4x4Upgrades