I added sound insulation to my Kona Electric

[EVPower]

rear left wheels arch done.

After some clean up, you can see that Hyundai has put some noise insulation on the plastic and some rust proof too. I added some noise deadening on some element of the suspension, the accessible part of the battery case that sounded more hollow and way more inside.

From the driver perspective, the left rear sound is less louder now. Can't take a spectrum and db test because I was alone. Will have a metric really soon from the rear position like last time.

 

[EVPower]

I had time and a driver to test now and the frequency reduction is between 70 hz and 85 hz since the insulation. DB hasn't changed but from the perspective of being in the back but seem a bit lower but not by much. Keep in mind that the plastic cover is not reinstall but when I will, I think the sound will be more muffled.

 

[EVPower]

Rear Right wheels arch done.

 

[EVPower]

Roof Deadening done :

I have install the closed foam almost on all the right side. Will compare temperature between metal, stock insulation and mine.

 

[electriceddy]

Roof Deadening done :

I have install the closed foam almost on all the right side. Will compare temperature between metal, stock insulation and mine.

Looks like one of the roof support trusses bent down a bit (adhesive let go).
Was that from forcing off the finish material a bit too hard when removing, and did you re-apply adhesive to repair it?

Be careful around those curtain airbags. Also... if you could take a closeup of the removed covering around the front mirror camera area, would be appreciated

 

[EVPower]

Yeah, I forgot to mention this but I was careful when removing it but yeah a support was unglue and this part support the rear passenger side middle light. Will try to fix it but don't know with what for now.

The airbag are a pain in the a**, there are everywhere, for a reason, I know. But just trying to unplug the cable from the front left side behind the pillar took me more than 10 minutes.

Will take you asked photo soon

 

[EVPower]

Roof continue .... and temperature.

 

[EVPower]

Roof completely done.

The metal bend was my fault. I tough that the rear middle light was only snap it and pry a little. Afterward I remove the plastic and saw the two little screw. The metal are only glue. I try my best to correct it buy adding more soundeading to the bracket.

Anyway, all is done now and reinstall.

Sound test will be done soon.

 

[Vince08]

Thanks for sharing the photos. Good reference if I ever decide to do the same DIY.

Off topic, some of your images clearly show the side and curtain airbags. My car comes with rear dashcam but not factory installed. The installer ran the wires along the edges of the roof liner and A-pillar which will potentially block the air bags from deploying properly. Your image clearly shows the areas that must be kept clear for the air bag to work properly. I am arranging with the dealer to re-wire the rear dashcam before someone gets injured.

 

[EVPower]

Glad it can help someone. Hope they did correctly for you.

 

[mikael nielsen]

Maybe it will be possible to make a directional sound measurrement to locate the worst noise sources and start with those. Anyone thied this or have the equipment to make that kind of measurements?

 

[EVPower]

Don't have the equipment for that. I'm open to a meet and compare my car almost completely done vs a stock with a good equipment. Right now, i'm was only a phone with a decibel app. Better then nothing but not a professional metric.

I didn't post my last db test for the roof, because I changed phone and the db measure wasn't the same as my old db measure tested. I saw no improvement except that when raining, I hear nothing compare then without any insulation.

 

[EVPower]

Strory short : Needed to replace the gearbox oil (43k km) and check the sound insulation near there at the same time.

The trip before mod : avg 74 db
After : 73 fb

Installed noise deadening on many bracket, under the upper cross beam, wiper motor, etc.

Added some Foam to the accessible firewall (20% at most). To many stuff needed to remove to correctly done it.

Done the wheel Arch that will surely help.

Added noise deadening and full undercover motor.

So I call it a wash. But saw I change in frequency over speed bump and less high frequency in highway speed. The remain are all road and tire noises. So I can diffidently close the case. Cannot optimize it further except by buying a newer ground-up EV.