SKU 425 SKU 430 SKU 435 SKU 440 This upper kit offers increased levels of rotor sound (whine) within the cabin but does not require drilling through the firewall.
Upper Sound tube
1 3/4” hole saw
1 large grommet
3 nylon spacers
1 large grommet
1 6mm nut
1 zip tie
Cut the OE sound tube in the middle at the point of the yellow line (see image). Install in the stock location using the supplied 6mm nut. Cut the OE sound tube in the middle at the point of the yellow line (see image). Install in the stock location using the supplied 6mm nut. Remove the white or black foam from OEM sound tube
Remove the 3, 10mm nuts from the accelerator pedal and remove the pedal. Once pedal is removed cut around the opening of the sound tube entry hole (see diagram) using the supplied blade. Check that the sound tube seal lips are completely inside the firewall and completely pulled all the way through the firewall.
If necessary use a small flathead screwdriver and a pair of needle nosed pliers to pull them through over the firewall.
Place the supplied 3/8” nylon spacers on the studs and attach pedal.
Image shows nylon spacer installed
Drilling the airbox with the air filter in place using the 1 3/4” hole saw supplied in the kit.
Mark a point 1.5” down from the top of the box and center it between the brass studs and drill.
Insert the large grommet (supplied) into the drilled hole in the air box to secure the sound tube.
Push the grommet into position into the hole using WD40 for lubrication.
Insert the larger end of the supplied sound tube into the rubber grommet using WD40 (pinch the tube ends to help compress it into the tight fitting rubber grommet) so approx. 1” extends through into the box.
This needs to be a tight fit between the sound tube and the grommet. Use your fingers to pinch the end of the hose while pushing hard to insert the hose into the grommet.
Install the Sound tube over the hard plastic OE tube previously cut and installed into the firewall in Step 1.
Use a lubricant such as WD40 or a soap & water solution to facilitate the fit.
This is a friction fit and no additional fastening is required. The installed upper sound tube is now visible in the image and the install is now complete.