How much horsepower can a 4G18 engine be modified to?

[OEmmanuel]

4G18 engine can reach 140-150 horsepower after modification. Modification of intake and exhaust systems: The low power output of the 4G18 mainly lies in the engine's intake and exhaust systems. By modifying with a MIVEC system similar to Honda's VTEC, the valve timing and lift can be appropriately adjusted to achieve maximum combustion efficiency at both high and low speeds, thereby improving power output. Modification of high-angle camshaft: By modifying this component, the duration of valve intake and exhaust can be extended, significantly increasing power output. Additionally, the engine's intake and exhaust systems are polished to ensure smoother "breathing." Increasing the engine's compression ratio is also an important method to enhance the output of a naturally aspirated engine. Using thinner gaskets simply achieves the goal of increasing compression.