Project 981 Cayman - Soul Performance Exhaust System (Episode 8)
Project 981 Cayman - Build Series
On this week's episode we install the Agency Power Headers and Soul Performance Valved Cat-Back exhaust system.
The factory exhaust system creates a civil tone but has a lot of restriction in order to meet emission and sound compliance. The factory headers use ovalized crushed runners that feed a massive catalyst constraining exhaust flow. The factory mufflers are large and shove the air into a T exit.
The install is straight forward. We began my removing the cat-back and then the headers. The headers are secured by 9 torx bolts on each bank. The flanges that mate to the cat-back are secured by 2 bolts. We recommend replacing the header gaskets when replacing the headers. The Soul Performance exhaust came with new flange gaskets. Everything goes back on the way it came off.
Agency Power Headers vs Factory Headers
Factory OEM Exhaust
Agency Power Headers
Soul Performance Cat-Back
We ran the vacuum lines down from the engine bay and utilized zip ties tucking the lines behind the factory heat shielding near the bumper. The wiring was a little trickier. We tapped a hot 12V source from the fuse box in the trunk on the passengers side. We had to remove some panels and trim to conceal the wiring. We ran it into the engine bay along with the factory wiring harness. We put a small cut into the rubber that protects the factory harness and sealed it up with some silicone. We then programmed the homelink buttons inside the car to open and close the valves.
With the valves open, the exhaust sounds brutal. A cup car sound, very aggressive. It's loud and powerful sounding. Tons of crackles and pops when you lift off throttle. Cruising with the valves open isn't terrible but there's a good amount of drone in the cabin. Once you close the valves, the drone goes away and the car becomes much more composed. You still have a nice exhaust note but no loudness inside the car and a civilized sound when cruising.