Noise Killing
Niva isn't the quitest car on Earth ... Some say World War I tanks were louder but I doubt it...
Materials used:
Total cost - about USD 350.
Tools:
The job:
First, all interior is gutted to the steel (excluding roof). Now it's a good time to examine the firewall and decide on wiring layout.
Starting with engine space and firewall - laid down one layer of metallized QD (don't use hot blower under the hood!). Inside, removed the steel sheet covering the fuel tank rack, and padded this hidden compartment with QD strips. Sprayed the steel surfaces with undercoating. Then dumped a few blobs of foam in between the tank and body panels - so it's secured tightly but not blocking moisture. Later, same sort of treatment secured the inner and outer door panels.
Priorities were first firewall, floor and and gearbox tunnel, - then doors and rear fenders, - then trim panels. I didn't focus on doors a lot since the 1999 install didn't use door space.
Firewall and floors received 1-2 layers of metallized QD, then another layer of plain QD. The trickiest point was getting behind the heater (which I didn't want to remove) where the engine noise penetrates the cabin. Then, laid 5-mm metallized PE mats on the floor. Laid down power wire (in a PVC tube, right floor edge), acoustic (flat on the floor) and RCA (left floor edge). Some drilling was required to pass the cables through the seat support structure. Power wire is construction-grade Pirelli 36 sq.m. (AWG3), means I got it free. Bends easily, heat-rated to 400"C ambient.
Acoustical cables are flat and need no special protection, just a stock rug, but the RCAs needed special treatment. Using three layered PVC sheets, I buried them as securely as possible. Here's the sequence.
BTW, the layers of metallized PVC are actually one large capacitor with some foils grounded, some floating. I don't know if it's good or bad, I never experienced any electrical noise problems - the car is computer-free, the most compleõ native piece of electronics is the ignition switch.
This is a perfect moonscape , what's left outside the picture is a lot of work quieting down the plastic trim pieces.
Results:
Frankly speaking, the engine is still noisy, and so is transmission but the noise spectrum changed. All low rumble is as it was but the mid-frequency noises - fan, trim squeaking, wind noise - are suppressed very effectively. And when the common folks ask me 'what the hell is this and that' I can proudly knock on the hood and leave them bewildered by this quiet 'thump thump'...
