Reducing NVH
 

Anyone have any tips to reduce NVH in your CRX's? I'm running a bone stock 91 CRX HF and am rebuilding this car with MPG and daily drivability in mind. The car is pretty loud and was hoping people had tips on some low hanging fruit to reduce noise and vibrations to the cabin. It seems the POLY inserts in the rear engine mount were a bad idea though, lol, which is a shame because the car becomes much more responsive on the road.

Some of the thin dynomat will help without adding too much extra weight to the car.

Where are the best places to put it?

When I still had it, my Dodge Caravan appeared to be a collection of parts flying in close formation, and none were especially respective of each others' personal space. It was a rattly, squeaky disaster.

I spent a couple of hours one weekend before a big trip, taking every interior panel off and reinstalling it with a thin piece of leather under each contact point. I got the leather from a messed up jacket someone was throwing away, so my entire investment in the project was time. It helped a lot, but it wasn't everything. An old CRX should have some opportunities for you to find attachment points and make necessary modifications.

I think Dynomat works best on larger thin metal panels. Your CRX has some tar-like matting already. I usually scrape the factory stuff out because it's heavy. I don't notice a difference in noise.

My Wagon with a gutted interior is really loud inside. It's mostly tire noise. Insulating the floor and wheelwells should help.

I want to make my CRX a lot quieter than my Wagon without adding much weight. Please post any noise reduction results here.

I'd do was gasoline fumes mentioned about dynomat on the wheel wells and floors and add that a piece on the roof will help too. Some NVH can be address by just making things tighter like elhigh did in the interior but also making sure exhaust hangers are tight too....at 2000rpm my Focus exhaust rattles like crazy in the cold. New Weatherstripping for the trunk and doors will help reduce wind and road noise too if yours has seen better days.

When you're next to a hard acceleration truck and crack open a window, notice that even the tiniest opening lets in 90% of the noise. Start by sealing up any gaps where factory grommets and seals have degraded over the years.

Second thing I realised about sound proofing is that you'll always be limited by the car's glass, most of the noise in my Renault comes in through the large areas of glass, sound proofing the rest of the car is of little value, unless you have a specific problem.

My Wagon got noticeably louder when I removed the passenger's seat. I'm not sure if the seat was blocking noise from the rear tires or absorbing the noise. Maybe both.

You have poly inserts in the rear engine mount only? Can you take them out and try stiffening the front mount instead?

The front mount isn't there anymore. I changed my front crossmember to an aftermarket unit and there's no mount there for the motor.


I think i may make an underbody panel for aero reasons and try and seal it well from bumper to bumper. I'm hoping this will reduce some noise as well.

I was thinking about trying to dynamat the floor and up the firewall, then realized good floor mats would essentially do the same thing with almost 0 effort. Got some universal mats from weather tech, and thought they helped