The early version of the 1GR-FE comprises a heavy crankshaft, heavy pistons, and a single VVT-i system on the intake camshafts. In 2009, newly modified 1GRs equipped with a dual VVT-i variable valve timing system on the intake and exhaust were introduced to replace the initial launch of the 1GR. Dual VVTi adalah teknologi yang memungkinkan buka tutup katup otomatis tepatnya di bagian katup intake dan exhaust valve. Inilah yang menjadi perbedaan VVTi dan Dual VVTi. Pada tipe VVTi, hanya katup intake saja yang dilengkapi dengan fitur pengatur waktu buka tutup. Wrong.". "The stock 1JZ bottom end is good for 650-700, which is 260 - 280 hp/liter (650hp/2.5liter=260hp/liter). The stock 2JZ bottom end in good for around 800, which is 266hp/liter.". "Both of these engine's bottom ends have been pushed way past the numbers I've just quoted. The VVTI gear moving forward has a range of motion not just an on/off function. As a result you can have VVTi partially activating to different extents depending on throttle input. You can feel it working from near 3000 rpm and up under 1/2 and above throttle press. It will feel like its pulling harder in a certain RPM range. Vay Nhanh Fast Money.

single vvti vs dual vvti