Generally speaking, larger pipe diameters will result in better horsepower output performance at high rpm range. However, this isn’t to say that larger diameters equate better highend performance; when the diameter size is too large, exhaust gases will not be able to fill up the holding space of the exhaust pipe and the exhaust gases will create turbulence and exhaust outflow issues , which will negatively affect performance. Exhaust pipes with smaller diameter sizes are perfect for torque output under low revs. When the car is operating under mid to low rpm range, exhaust gases can be released quickly, but under high rpm, large volumes of exhaust gases will be blocked inside the exhaust system and subsequently increase the exhaust temperature. Therefore, the Fi Team designs and customizes every exhaust pipe with precision and utmost care based on their original fittings, with the aim to greatly increase horsepower and torque performance through an optimal diameter ratio. With our exhaust systems, you will see a breakthrough in sports car-like sound performance not available with the stock exhaust systems. Fi Exhaust Team will be looking forward to seeing you enjoy the exhaust system that are the culmination of our determination to bring you perfection, and the persistence on the finest details.