Road Noise Reduction
My 88 S4 has always had lots of road noise. My first tires were Goodrich Comp T/A's, and now Dunlop SP8000's. The Dunlops are quieter than the Comp's, but not my much. I suspected that much of the noise is getting into the cabin via the rear wheel arches, so I deceided to do a bit of soundproofing. I removed the rear wheel inner fenders, and found that the factory undercoating is very thin. After carefully cleaning the area of loose road grime, I used four cans of rubberized undercoating spray per wheel (total of 8 cans), slowly building up a coating of close to 1/4 inch. I only sprayed the stuff on the metal surfaces that form the wheel arches inside the cabin, and was careful not to plug up any drains. I just drove it today.. the results are stunning.. It was really effective and much quieter. I am very pleased, and maybe I can get even better by getting quieter tires next time. I'm not suggesting it will work for everyone, but it sure worked for me.
Keep the shiney side up :)
88 S4 Granite Green 38K and rising
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