Young Version — April 1998

I have a question and decided to write. There are turbo and naturally aspirated versions of mufflers—what is the difference? If I install a bolt-on turbo on a naturally aspirated car, is it bad to keep the NA muffler? For a turbo setup, what pipe diameter is best? In the future, I plan to buy an Integra Type R and install a Kakimoto exhaust. (Katsuya Nakamura, Hita, Oita)

Generally speaking, the biggest differences are pipe diameter and the muffler's internal design. Turbo mufflers usually have larger pipes for better exhaust flow; internal construction varies by maker—for example, a straight-through design for turbo models and baffles for NA models. The choice depends on whether you want peak power or stronger midrange torque. A naturally aspirated car with a bolt-on turbo does not necessarily have to use an NA muffler. Choose the muffler to suit the level of tuning. Consider the turbine size, engine modifications, and boost pressure, rather than choosing solely because the car is turbocharged. Budget and appearance matter too, and it's best to consult a shop with plenty of experience and data.

People say the 13B-T has a short life, but in practice it isn't necessarily much less durable than a piston engine. Tuning can reduce durability, depending on the modifications and how the car is used, so it is not accurate to call it simply weak. With ordinary use, you probably don't need to worry too much. A rebuild may be needed depending on mileage, but it takes time and effort; another option is a good used engine from a salvage yard or a rebuilt exchange unit. Exact prices vary, but budget around ¥300,000 plus labor…