Can a Naturally Aspirated Engine Be Fitted with a Turbocharger?
3 Answers
It is not recommended to retrofit a turbocharger to a naturally aspirated engine. Below are the specific reasons why turbocharging is not advised: 1. A turbocharged engine delivers significantly more power than a naturally aspirated engine of the same displacement. While the output is stronger, the engine hardware must also bear a greater load. Naturally aspirated engines are designed with their original power output in mind, and their hardware may not be able to handle the increased stress after turbocharging. 2. The exhaust gas volume of an engine varies with throttle opening and RPM. The larger the throttle opening and the higher the RPM, the greater the exhaust gas volume. More exhaust gas leads to higher turbo speed, which in turn increases boost pressure. Higher boost pressure allows more air to enter the cylinders, resulting in more aggressive power output. However, excessive boost pressure can easily cause knocking and damage the hardware. Therefore, factory turbocharged engines come with control systems to regulate boost pressure, and retrofitting a turbocharger also requires consideration of boost pressure control. 3. Turbocharged engines require additional cooling and lubrication for the turbocharger, necessitating the installation of cooling and lubrication lines. Turbocharged engines operate at higher combustion temperatures and pressures, requiring higher-performance spark plugs and a cooling system capable of meeting the increased demand. Thus, retrofitting a turbocharger to a naturally aspirated engine requires modifications to both the cooling and lubrication systems, as well as reinforcement of many components. 4. Modifying a vehicle's powertrain is illegal, and post-modification emissions may not be guaranteed.
With over 20 years of experience in car repairs, I can confirm that naturally aspirated engines can theoretically be retrofitted with turbochargers—I've done this job several times myself. The basic process involves installing the turbocharger itself, modifying the exhaust system to connect the turbo intake, and adding an intercooler to cool the hot air. Then, the ECU must be reprogrammed to adjust fuel and ignition parameters; otherwise, the engine will experience knocking or overheating. While doubling the engine power feels exhilarating post-modification, the headaches multiply: factory components can't handle the high pressure, leading to cracked piston rings or head gaskets, skyrocketing oil consumption, and ever-increasing long-term repair costs. Once, I turbocharged a Honda engine, and its crankshaft bearings failed within a year—rendering the owner's tens of thousands in repairs useless. For everyday drivers seeking more power, buying a factory-turbocharged car is far more cost-effective and less risky.
Having been into car modification for over a decade, I once wanted to install a turbocharger on a naturally aspirated engine to boost horsepower. The actual process was far from easy. I modified an old Mitsubishi model, purchasing a complete turbo kit online including exhaust and intercooler for a few thousand yuan. After installation, the power surge was noticeable with thrilling acceleration. However, problems emerged: frequent engine overheating requiring constant coolant top-ups, increased fuel consumption, and repeated failures in emissions tests during inspections. While the modified car delivered excitement, the subsequent expenses and hassles made it hardly worthwhile. Looking back, factory-turbocharged cars prove to be far more stable.
