FR Sport Exhaust Bite: Tomei Ti Expreme Prototype + 2015 Subaru WRX STI
Product P/N: 440018 Available now at www.frsport.com We drove our brand new 2015 Subaru WRX STI out on the local roads with a prototype (as of editing) ...
Short answer... Because Race Car haha. But in all seriousness, it's for extreme weight reduction and fastest possible exhaust airflow. By only having one route and exit, the exhaust air flows faster and more efficiently out of the car. By reducing the number of pipes to one, you also save the added weight of another exhaust pipe and Tomei charges you less money because they used less material in the process. Hope that helps. - JMR