View Full Version : Question regarding sound insulation in the trunk
nucjd19
02-09-2021, 09:45 PM
Question to the FFR hive mind
I am currently installing Kool mat in my cockpit from Breeze which is an awesome product. So, I am looking to my trunk area and trying to decide what to do. I have installed the RT drop trunk and the FFmetal drop battery box. Finally I am installing the Breeze cubby mod.
So my question, is sound deadening beneficial in the trunk vs placing the carpet down to the aluminum? If yes then can I get away with a cheaper product like dynamat etc compared to the kool mat which is rather pricey.
thank you in advance for the advice!!! Pics for your time......
https://thefactoryfiveforum.com/attachment.php?attachmentid=142383&d=1612924670
https://thefactoryfiveforum.com/attachment.php?attachmentid=142384&d=1612924678
https://thefactoryfiveforum.com/attachment.php?attachmentid=142385&d=1612924693
Just my opinion but any sound deadening material on the aluminum seems to help take away the "tinny" rebound it gives off. I think you would be fine with using Dynamat and save a few bucks.
Nice job on the build! Your making some good progress!
nucjd19
02-09-2021, 10:21 PM
Thank you Fman!!! i was wondering about the overall sound of the car in total in addition to the trunk.
rich grsc
02-09-2021, 10:26 PM
If you're going to ride in the trunk, yes.
nucjd19
02-09-2021, 10:33 PM
If you're going to ride in the trunk, yes.
Good point! back when I was a teenager piling folks into my ride it would have much more of an issue :) To your point that was my issue. Does the sound of the rig really change from not insulating the trunk area?
edwardb
02-10-2021, 07:01 AM
This subject has been tossed around some. But likely all you'll get are opinions (including mine...) because no one that I'm aware of has done one with trunk insulation and one without and can provide actual evidence of the difference. If any. There is no question that bare aluminum has a different sound than aluminum that has been coated or covered with insulation. Easy enough to confirm just by tapping on it before and after. I'm convinced it makes a difference in the cockpit including the foot boxes where you're closest to the engine, pipes, road, etc. Aside from the desired heat insulation. But for the trunk? Probably not the same. I've done Lizard Skin in my Roadster builds. So it was easy to include the trunk area while spraying. Literally only adds minutes to the job. But I probably wouldn't have extended to the trunk if I were using one of the stick-on products. Having said that, I prefer carpet in the trunk. Both for the appearance and so junk I throw in there doesn't rattle. Whatever sound insulation that provides it just an added bonus. If you're planning on carpeting the trunk I'd recommend that's going to give you as much benefit as needed. Again though, an opinion. :p
Jeff Kleiner
02-10-2021, 07:44 AM
As Paul said, just opinions. For what it’s worth I have never insulated the trunk in any of the roadsters I’ve built but I have however carpeted the trunk in every one. Takes away the “tinniness” of raw aluminum and helps to keep items from moving around.
Jeff
boat737
02-10-2021, 10:50 AM
I did just carpet in the trunk on mine. (With lizard skin and carpet in the cockpit.)
Another one that just used the sound dampening in the cockpit, not the trunk. I did cover the trunk with a trunk liner, not carpet material, and have no obvious "tinny" sounds from the trunk area.
https://thefactoryfiveforum.com/attachment.php?attachmentid=93968&d=1537567921
Dave
AC Bill
02-10-2021, 01:05 PM
I carpeted just the trunk floors.
Never really noticed any tinny sounds. Rear cockpit bulkhead is insulated & carpteted, so perhaps that helped.
nucjd19
02-10-2021, 07:00 PM
Thank you for the responses everyone! I was planning on only carpeting the trunk but I had seen multiple builds like Edwardb's that did sound insulate and just wanted to make sure I wasn't making a mistake by not installing insulation in the trunk.
Nigel Allen
02-10-2021, 07:53 PM
Without trying to hijack the thread, is it worth putting sound deadener on the top half of the fuel tank to try and reduce the noise from the in tank pump. My Walbro is mildly annoying.
Cheers Nigel
Sdonnel
02-10-2021, 07:59 PM
I took pieces of sound mat and placed them across the top of my tank. My Walbro pump is barely noticeable even before the car is started. I simply tapped on the tank and found the spots that seemed to resonate sound and applied accordingly.
Scott
It doesn't take much to dampen the sound.
https://www.youtube.com/watch?v=5ZPT70Hteo4