It was a lot of work, but I successfully retained my stock heat exchanger, and added dual exhaust to the mid point of the car. This exhaust is similar in design to the factory Hawaiian exhaust with out the heat exchanger. I am so happy with the newfound torque improvement , it is unbelievable !!.
https://www.youtube.com/watch?v=6tUZ2rViWuw
Mark Portland Or.
The 2014 National Microcar Show is at www.gpnwmme.com and is sponsored by www.mphspecialties.com