At what RPM does a 1.5T turbocharger kick in?
3 Answers
The turbocharger is engaged at all RPMs. The specific engagement of a turbocharger is related to engine displacement - larger displacement engines typically have lower engagement RPMs. In essence, the turbocharger is constantly engaged. The fundamental principle of a supercharger is that the engine is equipped with an air pump, where the boost RPM matches the air pump's RPM. There's no concept of an engagement RPM, meaning the turbocharger starts working as soon as the engine is started. Types of turbochargers: 1. Constant-pressure turbocharging system: This system collects exhaust pipes from all cylinders into a sufficiently large exhaust manifold before introducing them to the turbine. Despite alternating exhaust pulses from different cylinders, the pressure at the turbine inlet remains essentially constant due to the stabilizing effect of the exhaust manifold, hence called a constant-pressure system. 2. Pulse turbocharging system: This system aims to improve energy utilization efficiency that would otherwise be lost in constant-pressure systems. Its characteristic features include short and thin exhaust pipes, with the exhaust system volume minimized to allow exhaust gases to rapidly enter and expand in the turbine, thereby reducing throttling losses.
Answer 1: I usually enjoy studying the technical details of cars. The turbocharger engagement point generally depends on the engine displacement. For a 1.5T displacement, the turbo typically starts to engage around 1500 rpm and reaches full boost by 2500 rpm, though this varies based on the car's design. For example, smaller turbos respond faster and engage earlier, while larger turbos enhance performance but may engage slightly later. When the turbo engages, exhaust gases drive the turbine blades, increasing intake pressure and boosting power. I've test-driven several mainstream models, like Honda's 1.5T, which shows noticeable acceleration at 1600 rpm, while Ford's might not kick in until 2000 rpm. Factors like ambient temperature and altitude also play a role—cold weather can slightly delay engagement. Overall, good design makes the car more responsive at low speeds, but it's important to avoid excessive throttle at low RPMs to prevent component wear. Driving at the right RPM balances fuel efficiency and durability.
Answer 2: As an ordinary driver in daily life, I've driven vehicles equipped with 1.5T engines, and the turbo engagement point is quite noticeable. Typically, around 1700-2200 rpm after pressing the accelerator, you can feel the car suddenly gaining power, with a strong sense of acceleration pushing you back into the seat. When starting from traffic lights in the city, if the rpm drops below 1500, the turbo might not be fully engaged yet, making the car feel sluggish; but once it exceeds 1800 rpm, the acceleration becomes much smoother. From my experience, there are differences among brands: for instance, domestic models engage earlier, while European and American cars slightly later. Paying attention to changes in engine sound while driving can also help with fuel efficiency, such as maintaining cruising speed within the turbo engagement range. I recommend feeling it during a test drive—driving smoothly is more enjoyable, so avoid rushing to shift gears or accelerate abruptly.
