It's easy to spend a fortune for little results. I hope this posts helps you to get effective results. When done right, the engine and exhaust is more audible, and they general driving experience is greatly enhanced.
Weight? for all this weighs? if you really that worried, go on a diet and get a thinner bird lol.
Your problem areas are the doors, boot floor, and rear quarters. I'll tackle each individually.
Materials that are effective.
Dynamat extreme - not the std stuff which will peel off in the cold. Effective to stop panel resonance, also good for creating enclosures to make proper seals in cavity's etc.
SA25(FR)SA from http://www.soundservice.co.uk/Soundabso ... erials.htm. This self adhesive model is very good at tackling tyre roaring. It can be applied to the boot area, rear quarters, and between the door card and the inner skin. Being foam there is no weight penalty.
Noisekiller Lead Sandwich - http://www.noisekiller.co.uk/materials.php. Make a tight fit under mat for your boot carpet. Very effective. Can also be applied under your floor carpet.
To the job next.
The doors may not seem a big problem, but when you sort the boot and quarters it will become the main one.
Use dynamat extreme on the outer skin, but dont over do it. Cut smaller bits and use them to seal up the openings in the door before refitting the plastic sheet. Apply SA25(fr)SA to the inside of the door card where it will allow you to.
The quarters, famous nissan problem. Line the arches with a double layer of dynamat extreme, along with a single layer on the outer skin. Fit SA25(FR)SA in double layer over the wheel arch and single layer on the outer skin. If you feel rear adventurous, try using a dyn ext to create a seal for the inner skin leaving a little of the backing where the seat belt does through. Add SA25(fr)SA where it allows on the inside of the cover panel.
The boot. Remove the boot panels around the side and stuff all the SA25(fr)SA where ever it allows.
Cut some Lead sandwich the same size and shape as the boot carpet (leave it a little big and trim in place) so as it seals the lower boot area.
You should now have a very low road noise, so you can hear the excellent exhaust and engine.
For those who really want to go to town on this-
remove the interior, and fit the lead sandwich to cover the floor, you will have to make a few cut-outs for things. You could even put some under the back seat if you wish.
And for the perfectionist, dynamat the inside of the roof skin, believe me this actually makes a difference! as sound radiates through the panels to this one which is closest to your ears.
borrowed