As promised, the missing updates from my sound deadening project
Sound Deadening Part 8: Wheel Arches - June 2019The factory sound deadening on the arch liner for comparison
I found that the combination of foam on the wheel arch and wheel arch liner meant the liner stuck out just a bit too far and rubbed on the wheel when I turned it full lock. So I had to take it off again and remove the foam from the liner and just have the foam on the arch instead.
I don't remember this making that much of difference to be honest, but that might be because of the extensive work I had already done making it quieter already.
Sound Deadening Part 9: Door Seals - July 2019I can't remember where I got the idea from, but I bought some fish tank hose and some WD-40 silicone lubricant and fed the tube into the existing door seals to pack it out a bit more to create a tighter seal.
I think that either it didn't work well or I found a better solution, but I ended up buying 15 metres of
8mm thick Neoprene Sponge Black Cord and using the WD-40 silicone lubricant to feed it through the door seals.
I bought 8mm, but I think you could get away with 10mm
It worked great, and at first the door was a little hard to close, but after a bit of time the seal settled in and closed fine.
I also ordered a seal for the gap between the two doors. This was pretty easy to fit and is holding up well over 2 years later.
The one I purchased is no longer available, but this is basically the same product:
https://www.aliexpress.com/item/10000287853842.htmlSound Deadening Part 10: Making the plastics fit better - August 2019I ended up removing a some of the sound deadening because the plastics weren't fitting well. I think I ended up removing about 6kg worth.
I also removed the butyl that was on the pre existing sound deadening to save a bit of weight
The bucket full of removed sound deadening
Sound Deadening Part 11: The Final Verdict - What I learnt and Was it worth it? There is surprisingly little official information about sound deadening online (mostly stuff from other DIY folk), and a lot of conflicting information as well.
So much I learnt from trial and error and just tonnes and tonnes of research. Including looking at Lexus car plans and seeing how they get their cars so quiet (mostly sound insulation, but also double paned windows, which I can't do anything about in the Jazz).
Here's the important stuff I learnt:
The Butyl layer doesn't need to cover everything. From research, only 33% coverage is really needed, anything more is just diminishing returns. So just putting squares on the areas that resonate most is all that is needed really.
Most of the people who need to cover every surface are people who enter professional car audio competitions, which is where most of the information on sound deadening largely comes from online. I found much better information when looking for sound deadening when converting a commercial Van into a mobile home.
The 3 layers of sound deadening:Butyl: stops panel resonance/vibration
Closed Cell Foam: sound insulation absorber (and also a needed barrier between Butyl and MLV)
Mass Loaded Vinyl: Sound blocker (not absorber).
If I was doing it all over again, I would not use anywhere near as much Buytl, I would buy the thinnest Closed cell foam and focus on the coverage with the MLV, as the MLV is what really makes the difference when it comes to sound deadening, so the maximum amount of coverage with MLV is best, but MLV is the most expensive part, and it isn't self adhesive like butyl/CCF, so getting it to stick to surfaces is a pain.
Was it worth it?No, no it wasn't worth it, given the cost (£500), time (100s of hours), added weight to the car (50-55kg) and amount of research and trial & error I had to go through to get to where I am now, it wasn't worth it.
But would I do it again with my next car, given what I now know and the experience I have?Absolutely! The car is significantly quieter and nicer to drive and just feels so much more premium. Hearing the soft door thud every time I get in the car is so nice. And when I'm a passenger in any other car and hear the loud clang of the door closing and all the road noise that gets let it, it reinforces how much nicer it is with all the sound deadening. Motorway conversations are also so much nicer, no raised voices. The insulation also helps keep it warm in winter and cool in the summer.
So I guess it was worth it then! I just hope I don't have to do it all over again in a hurry that's all! I plan on keeping the Jazz for the foreseeable future.
Hopefully this wrapping up of the build helps anyone thinking of undertaking this themselves.
If anyone has any questions, please feel free to ask!
Hopefully it will notify me this time!