Sound Deadening Part 6: Main Interior Closed Cell Foam and Mass Loaded VinylSo It's been nearly a month since my last update, and most of that has been me doing research and getting all the materials needed for the next stage of sound proofing.
This stage has been one of the most painstaking ones, not just because I had to remove the whole interior again (twice), but also because of getting things to fit back afterwards.
This build really isn't for the faint hearted, and part of me is regretting even starting this build! But I've come this far, and it's all about learning and trying new things.
So first step was to completely remove the interior (again), and cover the floor/boot in Closed Cell Foam.
I wanted to try and get as close to 100% coverage as possible.
So I removed the hand brake and placed a sheet underneath and cut out the holes for the screws, paying special attention that the main handbrake surround was still touching bare metal (for the grounding):
I was hoping to fit the Closed Cell Foam and the Mass Loaded Vinyl both in one day, but as per usual, I underestimated how long things take! So I managed to get all the Closed Cell Foam done in a day, and had to put the interior back in (just the Carpet, centre console and seats), as I had work the next day and needed to drive the car:
I used Gorilla Tape to tape up the gaps in the CCF.
So fitting the MLV took a total of 1 and a half days to do. I did the main interior on Saturday, and finished the boot area yesterday. This was such a pain in the arse, and made me want to give up the whole project because of how annoying the whole process was. None the less, I managed to get it done.
I used a sheet of
Dodo Barrier MLV 1.25m x 2.05m for the main interior, and I purchased a 5m x 1m sheet of slightly thinner MLV from
Car Insulation UK to do the rest of the interior (and possibly other areas depending on how much was left over). Total weight was about 26kg
I wanted to cover as much as possible, as MLV works best with total coverage, and I noticed that there was a nice big gap where sound could come in under the gear linkage. So I followed the service manual very carefully and removed the gear linkage:
Then applied some Closed Cell Foam:
And finally a layer of MLV, and fitted everything back:
Next step was to do the same with the Hand Brake. I wanted to make sure everything was easy to access if it needed to be adjusted in the future:
I wanted to put sound proofing over the cover for the fuel pump, as sound could get through that way, but I didnt want to cover it with CCF then MLV and for it to then be hard to access when the eventual time comes to replace the fuel pump/fuel filter. So I cut out a square of CCF and a square of MLV to cover it, and then stuck the CCF to the MLV, and then placed it on top, so when the fuel pump/fuel filter eventually needs replacing, the sound proofing can be easily removed for access:
The MLV was a nightmare to fit, as it doesn't stretch, and isn't self adhesive. So I had to make lots of cuts to get it to wrap around the contours of the interior:
I tried to get the MLV as high up the firewall as possible, but it was a nightmare to work with, had to settle at this height:
After running out of the Dodo MLV, I switched to the other MLV, which was so much easier to work with, due to being thinner. Did the rear seat area first, then put the interior back in:
There was a noticeable gap on the air ducts, so I taped them up just to be safe:
I fitted the side plastics first, and I'm glad I did, as they wouldn't go back at all, I ended up having to lift up the carpet and remove a large strip of the CCF to have enough room for the plastics to fit back. I wish I had used a thinner CCF, something like 5mm or 3mm to do the interior in hindsight:
After removing some of the CCF, the plastics did eventually fit back on, but there are still some noticeable gaps that I will just have to live with. They aren't too bad, but they are just annoying because everything doesn't look flush and perfect:
Side plastics and centre console all fitted in. Centre console was difficult to fit back in, but I got there:
Next was the boot area. I may have rushed this area a bit, as I was pretty annoyed by this point and just wanted it over with, so I may go back and tidy it up a bit at a later date, but it seems to fit ok for now:
I used all the off cuts of MLV and some of the stock Honda sound insulation that I had removed from the Door cards and rear plastics to stuff the void gaps above the rear wheel well:
So at present everything fits back in "ok".
I am having an issue with the rear seats at the moment.
I couldnt fit the base plate that the rear seats lock into on the floor, so I had to completely remove all the sound deadening around that for it to sit flush again. But now the rear seats don't lock into place when you put the seat part down (in normal position). I think this is due to the carpet being slightly raised from the CCF and MLV underneath.
I don't know if this is an MOT fail or not, but my MOT is due in less than a month, so I don't want to risk it, and I'd feel safer in the knowledge that it locks down like it is suppose to, so I'm going to investigate this issue tomorrow and see if I can fix it.
Initial thoughts after installing the CCF and MLV in the interior:
So, driving it for the first time, I noticed when the car is stationary and driving at very low speeds (up to 10mph), the car is near silent, like luxury car silent. But then the moment you get above 10mph, then the road noise just comes straight through. It is slightly more muffled, but still really noticeably loud.
I put this down to the tyres. It has Bridgestone Turanza ER370 tyres on it, and they are the standard tyres it came with from the factory. The front ones are nearing their limit, so I would imagine they have gotten louder over time, and are at their loudest now they are nearing the end of their life. I am looking at replacing them with some Yokohama BluEarth ES32's, which seem like a good all round tyre, and have a noise rating of 68db. But I'm not going to do that until the tyres actually need replacing.
There is still a lot of engine noise and I have a few tricks up my sleeve that I'm going to try (Mostly a complete bonnet liner (20mm insulation) and putting some MLV on the fire wall under the cowl), but I'm not going to get my hopes up. We shall see.
I also notice that now I have basically eliminated all the places where noise can come through, there is noticeable noise coming through the windows (like when other cars drive past). This is something I think I'm just going to have to accept I cannot fix (bar thicker glass).
I am also going to go down the door seal route, and see if that makes a difference.
I think when I'm done, I'm going to go down to my local Honda Dealer and ask to test drive another Jazz Si so I can actually see the difference for myself. As I have done all this gradually, so I'm not going to notice that huge difference I would have if I had done it all at once.
I did get the chance to drive my Landlady's New(ish) Mini Cooper not long ago, and one of the things I noticed straight away (apart from how poor the visibility was), was how loud the interior was, so if that's anything to go by, the sound deadening seems to have worked well.
More Updates to follow soon, and I will conclude this thread with all my research, products purchased, and the Do's and Don't's that I have learned along the way, so please bare with me.
Thanks