We are constantly talking about installing the most efficient parts on your car to produce better performance. For example, a free-flowing exhaust will increase the efficiency of the motor and in turn make power, but how do we apply this thinking to other aspects of the vehicle like, say, interior noise and the audio system? No matter how good your speakers are at producing music, they still have to overcome the ambient noise in the interior. Ever notice that your stereo sounds louder when you stop at a light? That's because the road noise cancels out some of the frequencies in the music. Road noise or big lumpy cams will have you turning the dial a few more clicks just so you can hear it. The best way to cut down interior noise is to cover the metal surfaces with products to increase their density to lessen vibrations or absorb sound waves altogether. 1 Here are the Boom Mat sound dampening sheets. Boom Mat features a foil top layer bonded to a dense layer of black stuff. For our subject vehicle, a ’70-1/2 Z28, we picked up the large box that came with 12 12x25-inch sheets. This is more than enough to cover the floor pan and some other areas in the interior.1 Here are the Boom Mat sound dampening sheets. Boom Mat features a foil top layer bonded Sound is just that, vibrations or waves that your ear converts to sound, so if you can cut out the unwanted vibrations it lets your ears just process the sounds desired, like your stereo or chatty passengers. Another added benefit to using these products is the insulation properties. You car will stay cooler in the summer and warmer in the winter-a major plus for classic car owners. One of the things we hear a lot is, "That sound dampening stuff is really heavy and I don't want it slowing down my car." To answer that concern, we are going to weigh the vehicle before and after so we will know exactly how much weight is added. This story will show you the newest sound dampening products offered by Boom Mat, a division of Design Engineering Inc. (DEI), and how to use them. The Boom Mat products are specifically designed to reduce road noise and dampen vibrations that plague older vehicles. Installing the products is pretty straightforward-peel and stick or spray and shoot-so most of your time will be spent disassembling your interior. 2 Here are the second layers of dampening products. On top is the Under Carpet Light (UCL) and on bottom is the standard Under Carpet (UC). The UCL looks very similar to carpet padding, but it’s an engineered product that has a lot of thought put into it, instead of just chipped up rags and lint squished together. UC is made up of a top layer of flexible, 1-pound-per-square-foot mass-loaded barrier material and a bottom layer of acoustical foam. We initially picked up the UCL to use on the roof panel, but because of how close the headliner is to the inner roof skin we decided not to put it up there until we have a headliner to check clearance.2 Here are the second layers of dampening products. On top is the Under Carpet Light (UCL 3 DEI offers all the tools and sundries needed to install the products. The roller and razor knife are pretty standard, but the company’s Boom Mat Hi-Temp Spray Adhesive is an awesome glue that can be used to stick down the UC and UCL. The Boom Mat spray is a unique vibration-dampening compound specifically engineered in spray form for hard-to-reach locations and irregular shapes. Total cost for everything used in this story was $743.76. The UCL is another $91.08.3 DEI offers all the tools and sundries needed to install the products. The roller and ra 4 To weigh the car before and after, we looked to Proform Parts for a set of four corner scales. The scales come with four scale pads with a 1,250lb capacity per pad, a battery-powered backlit display, carrying case, 20-foot cables, and even the batteries. These will not only help us with this story but will come in handy for setting up any chassis for a better-balanced vehicle. These are invaluable if you’re building a serious Pro Touring car or drag machine.4 To weigh the car before and after, we looked to Proform Parts for a set of four corner 5 Before putting anything down we stripped the interior, including all the factory tarpaper. After that we vacuum up any small particles or loose dirt.5 Before putting anything down we stripped the interior, including all the factory tarpap 6 After the car was stripped, we placed it on the scales to see just how much our ’70 Z28 Camaro weighs. The second-gen tips the scales at 3,190 lbs.6 After the car was stripped, we placed it on the scales to see just how much our ’70 Z28 7 With the surface ready, we laid out the sheets of Boom Mat to figure out the best use of the material. We pulled out three sheets and set them aside for the doors and upper inner quarter-panels.7 With the surface ready, we laid out the sheets of Boom Mat to figure out the best use o 8 Once we were happy with the layout, it was time to get sticking. The Boom Mat has adhesive on the backside that is exposed when you peel off the protective paper.8 Once we were happy with the layout, it was time to get sticking. The Boom Mat has adhes 9 The best way we found to apply the Boom Mat is to lightly drop it in place and stick down the center first, then work out toward the edges with the roller to prevent trapping air bubbles. To get the full benefit of the Boom Mat it has to be stuck to the metal, so if you happen to trap an air bubble use the razor knife to puncture a hole and let out the air.9 The best way we found to apply the Boom Mat is to lightly drop it in place and stick do 10 The stuff doesn’t really stretch, so in the low areas just cut a relief so the material will fully stick to the metal.10 The stuff doesn’t really stretch, so in the low areas just cut a relief so the materia 11 It’s a good idea to save all the little scraps, as they can be used to fill small voids.11 It’s a good idea to save all the little scraps, as they can be used to fill small void 12 We split one sheet diagonally and used that for the upper rear quarter area.12 We split one sheet diagonally and used that for the upper rear quarter area. 13 Here you can see where we used some of the scraps to fill small areas. 14 Now it’s time for the UC, which will be the second layer of sound dampening. The UC material is pretty thick and is a bit harder to work with than standard carpet padding. The UC comes in three different sizes (24x54 inches, 48x54 inches, and 54-inch widths sold by the linear foot), and we chose to get a few yards in a roll. Since the roll is 54 inches wide, we split it down the middle and created two pieces that are 27x60 inches. These will be used for each side of the floor pan. This will leave a bare strip along the tunnel that will be easy to fill in. You will run into this pucker issue at the front corners of the toe kick area.14 Now it’s time for the UC, which will be the second layer of sound dampening. The UC ma 15 After marking a line along the fold we sliced it with the razor knife to relieve the pucker.15 After marking a line along the fold we sliced it with the razor knife to relieve the p 16 Then, to cut off the extra material, just slip the tail under the cut and mark it.16 Then, to cut off the extra material, just slip the tail under the cut and mark it. 17 Now you will have a perfect line to trim along. 18 We also wanted the UC to tuck under the gas pedal mount, so we traced around it, cut slightly inside the line, and then pushed it over the mount.18 We also wanted the UC to tuck under the gas pedal mount, so we traced around it, cut s 19 After we had the piece trimmed, we folded it back over itself and sprayed both sides with the Boom Mat High Temp adhesive. Per the instructions, we sprayed both sides and let the glue tack up or dry slightly. Basically the glue should still feel sticky to the touch but not wet.19 After we had the piece trimmed, we folded it back over itself and sprayed both sides w 20 After the glue tacked up, we stuck it down inch by inch until the fold finally flipped over flat. An easy way to locate the seat and seat belt holes is to use a scratch awl pushed through the hole from the bottom.20 After the glue tacked up, we stuck it down inch by inch until the fold finally flipped 21 After repeating the process on the passenger side, it was time to cover the center of the tunnel. The reason we decided to cover the floor front to back instead of side to side is that it’s much easier than having to cut around the floor shifter and also deal with the puckers in the toe kick areas at the same time. If you are well versed in upholstery techniques, then we suggest going side to side, but the front to back is easier for the novice. We cut the center pieces a bit oversized and stuck them down, then we used the same tuck, mark, and cut to create a perfect seam.21 After repeating the process on the passenger side, it was time to cover the center of 22 We used some duct tape to cover the seam. We know it’s not pretty, but once the carpet kit is placed over the top it’s not really going to matter.22 We used some duct tape to cover the seam. We know it’s not pretty, but once the carpet 23 With the floor done, we moved to the doors. One sheet was cut lengthwise down the middle and those two pieces will be used to run lengthwise along the bottom below the impact beam. If there was no impact beam we would have used more of the Boom Mat, but there just isn’t enough room to properly work the stuff so we covered as much as we could.23 With the floor done, we moved to the doors. One sheet was cut lengthwise down the midd 24 To dampen the rest of the door skin we sprayed as much of the Boom Mat spray as we could without stripping out the door glass. We also used the spray on the package tray and the trunk divider.24 To dampen the rest of the door skin we sprayed as much of the Boom Mat spray as we cou 25 With that we were done, and it was time to put the car back on the scales. All the stuff we put into the car only added 8 lbs to the total weight—a hair more than adding one gallon of fuel. The additional 8 lbs is well worth the nice, quiet interior we will have. If you want your car to be quiet, solid, and cool, you should look into using Boom Mat materials for yourself.25 With that we were done, and it was time to put the car back on the scales. All the stu SOURCES Design Engineering 604 Moore Road Avon Lake OH 44012 800-264-9472 www.designengineering.com Proform Parts Roseville MI 800-521-1005 www.proformparts.com By Calin Head Enjoyed this Post? 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