The 2016-2018 Camaro came with a OEM sound tube system, on the ZL1 model the sound tube was deleted and a plug was used in the firewall hole the sound tube connected to. Remove this plug by unscrewing the small nut off the stud and pulling the plug cap off. This exposed the hole that will be used for the Foster SC sound tube kit.
Remove the inlet pipe with the MAF housing on open filter type intakes or remove box lid on closed system and drill a 1 ¼” (second to the last step on the bit) hole in the inlet pipe at the marked location. The hole is always drilled on the bottom of the inlet, the picture with the RED circle is a reference mark only, do not drill on the top of the inlet. Clean the edges of the hole with a razor knife and sand lightly. Install the rubber grommet and grease on the inside and on the 90 degree fitting and push into the grommet. This is very tight fit. This kit is designed to work on all inlet pipes and aftermarket CAI systems.
With some aftermarket intake setups there may not be enough room on the bottom to connect the sound tube. The alternate location may used on the side using the straight hose barb which will be pushed through from the inside.
Picture above is how the straight hose barb is inserted from the inside if using the side of intake or MAF housing.
With black RTV silicone make a nice continues bead around the hole like on the picture below (red circle is a reference mark for the RTV) keep in mind the size of the large rubber washer when doing so. With the rubber washer on the short end of the 90 fitting Insert the 90 fitting with washer into the hole keeping the barbed end pointing towards the driver side. From the inside of the car under the dash about a foot above the gas pedal you will see the fitting coming through the firewall now push the diaphragm cap on until its seated. You may need to have an extra set of hands to hold the fitting on the other side or wedge something to hold it in place while installing the diaphragm cap from the inside.