wheatswake

Solved! So there are 2 outlets on each muffler. In reference to a single muffler, one outlet has a flapper/damper in it and the other one does not. You can see this with a flashlight looking into the exhaust pipe. I want both outlets open. I connected the two vacuum lines in the trunk (bypassing the relay) with a 1/4" barbed hose union. Flapper/damper on both mufflers are open with car off and on. When disconnected you can hear the loss of vacuum and the flapper/damper closes. The pop/crackle is not achieved from what I can tell but at least I know all 4 exhaust pipes are open and not just 2. I did not check to confirm that with relay hooked up factory style, if flapper/damper is closed in eco or open in sport mode.

cyberay

Yes, I see that you did not bypass the relay, but you are on the right track now. Simply join the 2 vacuum hoses of differing diameters with a coupling and you’re done. There will be no crackles or pops because that requires ECM intervention. But the exhaust will have a very satisfying tone.

wheatswake

Cyberay,
Think you are looking at dbrown pics. I did bypass the relay. I just wonder if sport mode actually does open the flapper/damper when connected factory style to the relay. I never checked. One other thing I found while doing this is I thought the main batt. was under the spare tire tool/3D sub area. I have the 3D sub. My batt. is behind the backseat carpeted panel.

cyberay

Sport mode does open the valves though I’m not sure if they are constantly open or modulate at certain engine speeds or with other factors. All s coupe batteries are behind the passenger seat. Cars without the 3D sub have additional storage space under the trunk floor. Enjoy your modification.

wheatswake

So I have noticed after the car sits for more than 5 hrs the flaps go back closed, probably cause the valves on top of the muffler leak and do not maintain a vacuum. Hoping this will not be an issue. When I do start the car, they go open immediately.

cyberay

Five days is about right. Vacuum loss occurs very slowly with engine off. Mine is about the same. Dbrown167, on the other hand, has a constant vacuum loss because he used a tee instead of a coupling and seems to have left the unused port open. It’s a relatively small loss, but I would not want it.