Just thinking ahead with my rebuild, any recommendations for soundproofing under the carpets. Is it best to stick with a traditional kit cut from felt or better to use more modern adhesive type stuff like dynat? What do you think? Thanks again

 

If you can afford it, dynamat everywhere you can. Then put the OEM stuff on top. I have been in an XJS wwith this done and boy is it Q U I E T.
But, on the floorpans I would ensure you have painted on Rustbullet or PoR15 -type stuff before you glue anything down. The floorpans mainly rust from the inside out owning to damp carpets, water on shoes, etc etc. These coating effectively mean the water never gets to the steel.

 

Hello Brinny

I went with Chinese soundproofing over dynamat, mainly due to price. For the floor pans - instead of gluing the mats to the car - I glued them to the underlay of the carpet. That way I can remove them easily when needed. (As I have done on numerous occasions)

Cheers
Steve

 

I did the same thing, Steve... With lots of por15 Greg said. Glued the sound proofing I got from a great group in Mississippi (Albright Supply) to the metal (weldwood yellah),,, dabs here and dabs there,,, then glued SOME of the carpeting to the underlay,,, some not. Seems to be working ok...

 

Thanks for the assistance lads. What about any electrical cables if I use something that sticks down like dynamat? Do I bury them or keep them on top of the soundproofing?

 

On top, that is for sure!

 

Honestly,,, I didn't find much wiring in areas where there would be a permanent and complete seal of carpeting and underlay. There is the under console and interior tunnel area - loads there... I didn't go to crazy. I pushed and tucked underlayment where I could get, up as far as I could. At the rear the area that would be covered by the console/armrest and I COVERED a large bundle of wire that WAS covered when I went in, at the back of the arm rest towards the rear of the car... Seemed like the right thing to do. Believe it or not, in all areas it can get tight and fight back at ya in funny ways.

This is what I saw

 

Thanks. Are there any areas not to stick the dynamat too, like along the inside of the sills?

 

Hello Brinny

Along the door sils I have installed the mats - but have cut in access holes that will allow me to place the wax oil wand in there for yearly preservation services. Same for the boot area, so i can get the structural members oiled up, and along the area between the boot and rear bumper (where mine was really bad).

For the sils in front and behind the rear tires - I have left gap between the wall and the floor (so to speak) as this will still be a catch point for moisture and I think if you try to mat the base of these areas- you would just make it worse. I also have (or will have) access to put the wand in these area for the 12 month wax oil application

Cheers
Steve

 

I was thinking about areas where carpet needs to be glued specifically?

 

Hmm. The job is pretty slow going so I think that you'll find, no matter what I say, that you will be making judgments and basing your fitting on what you're seeing. I did cut out around the e-brake (if I'm getting what your asking) and I was careful about where the tread plates need to seat. Amazingly they have a pretty tight fit so pinning carpet underneath is about all they will tolerate. I am sure I only ran the underlay to about the upcurve on the sill and only carpet right up to the lip that separates the 'inside' from the 'outside' - if you know what I mean.

It DID NOT feel like a science to me when doing it,,, it gets a little "get it in",,,, if you know what I mean. Nipping and tucking. There is some wiggle room. The end product turned out great IMHO... I had never done anything like this before and me,,, well, I am not to hard on myself.

 

This is hugely subjective without instrumentation, but was it worth it? I don't know the condition of everyone's XJS, but one running properly, with the stock exhaust and proper door and glass sealing is still remarkably quiet by contemporary standards.

Are you Lexus quiet now? Any chance of a recording? (maybe you did a before and after?)

 

Just to return to this. Some areas have a factory fitted bitumen coating ie under the seat area. Would you go over this as well with the dynamat stuff ?

 

I didn't... I only went as far up as possible (with removing lots) at the peddles,,, and up and around and under where the dash starts to meet the console, then back a ways around the tunnel. I was mostly thinking about heat as opposed to sound. But both, ya know.

Mine was running so bad when I first started out (I didn't know how bad) that I was concerned about the amount of sound,,, but later, as I got things in a better place, it was more a heat thing. I'll have to say it was a bit of both.

 

Ok cheers. Did you find a difference both sound and heat?

 

I would like to say yes... But that would be dishonest...

I have NOOOO experience with these cars. The only only I've ever driven in, heard and felt the heat of is this one... I can only think that it (and 100's of other things I've done) is an improvement, lol... I have to think that OR,,, I'll go jump oft the Verrazano Bridge... Lol... This crazy car!!!

At least it's an improvement in terms of the car I walked up to 2+yrs ago now. Omgoodness...

 

And here I was thinking as I put the last bolt into my driver seat rail that I missed an opportunity to strip out the carpet from that whole side of the car while I had the seat out. Different strokes for different folks.

 

Which one lol

 

I would also recommend, on any space that is hard to apply a sound dampener, latex paint mixed with glass microspheres. You mix the microspheres into paint and then can either spray, brush or roll.

I did this on my car as experiment and was astounded at the difference it made.

If you wanted to be real cheeky you could use an oil based paint for additional rust proofing. But latex doesnt smell and is easy to clean up so that's what I chose.