Noise Reduction Options...

Some pic of the rusted out bolt location and the replacement:

 

Good job! I wonder if that type of insulation is available at Ace Hardware? Is it flame-resistant? I've been looking for a way to block some of the engine noise thru the firewall.

 

Thanks phoenixgreg. Search for Ultratouch. Yes it's flame retardant. I still have some leftovers for the interior firewall but I have to make sort of pillows of them cos it's quite fibrous and gets a bit "dusty".

 

Hi. You are right with those fasteners being really hard to remove if not you break them in the process. That photo you have with the liner off I'm going to tackle soon with my brush on undercoating as I've done the plastic liners with two topping off to maybe four coats of the spray on. The denim insulation (fire retardant, mold resistant, and pretty dense!) I lined the interior liners/wheel well area helped a lot especially at 100Kph and I'm satisfied with the results.

 

Hi phoenixgreg. I've been doing some research and stumbled upon Roxul Safe and Sound from Lowe's. It promising being flame resistant, and water repellant making it mold resistant so will make a good candidate for a liner even for a vehicle. It's rather thick at 3" I believe, so I'll be carving it to precisely fit that air gap by the rear well liner as well as the spare wheel area. At least that's the plan but I think it should work. I know your concern is the firewall and I'll do that as well but will demand more carving. The Roxul insulation from what I've seen doesn't dust up when cut unlike the denim insulation. We'll see...

 

I'd be interested in how you approach the outer firewall. I've looked at it and there's not much space between the engine and the firewall, not to mention all the connections, brake mechanisms, etc. to deal with. From the topside, it looks impossible, but then I wondered if insulation could be slipped in place from below? Of course there's the issue of removing the undercarriage plastic shrouding to get to it and then how to attach the insulation to the firewall staying clear of the exhaust manifold and cat converter. I will be interested in your progress and what you learn from it. I hope it works...I wish I had known about the denim insulation a few years ago when I did the Dynamat project on my car. Again, thanks for the tips on the Roxul...I'll do a search on it.

 

You're right about coming from the top. From the bottom I have to search for a thread on removing those panels... I think any insulation to the outer firewall be more towards the driver's side away from the ICE to avoid any heat/fire hazards. Meanwhile, when I tried to remove the front wheel liners it was such a pain so I abandoned it for the time being. I've seen from your pics that there is some exposed firewall when the liners were off so that will be a good place to start, firewall-wise. From your pics also there's that air gap between the frame and front quarter panel so gotta "remove" that gap too. Much of the noise anyways is airborne so insulating this will work much like soundproofing a home's walls right?
On a side note. I've been searching too about sealants and I've begun sealing gaps I see in the engine bay with high temp sealant. A bit hard cos space is really tight but workable. This might help but it's worth the try...

 

The front fender liners are not too difficult to remove. There's a variety of push-in plastic fasteners. One extra long one at front lower corner of bumper, and one at about 9 o'clock on the wheel well that has an integrated clip: it needs a 90 deg turn (and a bunch of wiggling) to release. Inside the fender well are a lot of simple, easy to release common ones.

The main problem for me was one towards the back, inside wheel well. If I recall correctly it's a screw going into a plastic push-in. The plastic seems near impossible to remove, you can see in pic it's still attached.

I'd be very disinclined to put any material in there, it's a grit and moisture trap.

Actually just occurring to me, maybe this is NOT the precise area you're targeting?

Anyway:

 

Thank you for the insights. My plan for the front will be in three (3) ways: First is to wrap the exposed frame of the car close to the suspension, the centre of the front quarter panel to the door, and the exposed firewall with BQuiets. Next, line the inner wheel liner from the top to about three quarters of the way w/the Roxul insulation. Lastly, "seal" the seams with brush and spray on undercoatings. I use Dominion Sure Seal from CT by the way. In theory, this approach should work and somewhat make my Prii come close to a Lexii. We're DIYers, we don't stop...

 

Hey guys, just wanted to share to you this hole/gap I noticed by the switches on the door armrest cos one time I rested my arm I felt a draft and then saw this. Your thoughts...

Note: It's just by the tip of the window switch to the edge of the panel, top right of pic.

 

kenniekenken, just wanna ask you for an suggestion, what would you recommend me doing for the first step to make the prius cabin quieter?
Thanks for sharing all your progress.

 

Reading the info on the SDS site is a good start.
www.sounddeadenershowdown.com
The treatments presented there are effective and not terribly expensive if you DIY and have a source for the materials so that the shipping cost doesn't kill you. Couple warnings... 1- count on it to be more difficult and time consuming than you think it's gonna be and 2 - as your car gets more quiet, you'll notice new noises and be tempted to chase those down.

 

thanks for your reply.

But that does not give me an exact answer what i should do first. Tires are already in my future purchase. I mean more for insulation type. and where?

 

Hey VicD sorry for the late reply, been busy at work these past few days... Anyway, to recommend, this is a bit complicated, only a bit though, lol! But from my experience, the first time I really "felt" a considerable improvement in the cabin noise was when 1) I did the floor panels where both driver and passenger rest their feet. Then 2) was the application of undercoating of the wheel wells. I have posts of these as well.
Now, to the "complication" I mentioned in the beginning, I actually did my doors, hatch, spare tire well and hood before anything else. The hood somewhat made the ICE go bassy which I appreciated. Doing the doors will improve mainly the sound quality music-wise, plus I practically got rid of the tinny nature of the doors making it more like when you close a luxury car, tight and solid, even the hatch! Upto this time every time I open/close my door(s) I feel proud of my accomplishments, haha!
Going further... Travelling 100kph on the highway the interior noise is quite nice compared to when I first got my car. My concern now is when there's crosswind I can feel a whooshing by the windows so that's what I'm gonna attack next.
Still a work in progress cos I still haven't gone under the car for more undercoat but with what I've put into it so far I gotta say I'm pretty happy
Sorry if I may have given you too much info but I hope I was able to answer your original question. If there's anything else I can help you with please let me know.

 

thanks for your detail info. can you please list the material you use for your floor panel and undercoating of the wheel wells?

FYI, I actually called the company that makes Ultratouch product, they recommend me using the radiant barrier for automotive noise cancellation project. do you have experience with that?

thanks

 

I tried a radiant barrier/foam product in the doors and floor. It was not effective for sound proofing the car and I ended up pulling that material out and replacing it with a layer of 1/8" thick 1 pound per square foot mass loaded vinyl that I mated to 1/8" thick closed cell foam.

Watch this short video that illustrates how effective insulation by itself is, and then shows an effective noise reduction system by combining insulation with mass loaded vinyl and a decoupler

With my first post, I was trying to save you time, $ and frustration by directing you to the info that the owner of sound deadener showdown has posted on his site, so you could learn about the correct use of sound deadeners like Dynamat, sound barriers like mass loaded vinyl, and sound absorbing insulation material, and how they work together as system. That way, you could make informed decisions based on your goals for your car and how much effort and money you want to put into it.

On my 2014 plug-in Prius, I have treated the doors, floor and cargo area by installing a minimal amount of Dynamat, liberal amounts of closed cell foam and mass loaded vinyl, and a little bit of insulation. I added about 80 pounds of material to the car, the materials cost about $200 and I worked my butt off to do the install on my own. My Prius replaced a 2012 Mercedes coupe, the Prii's now doors close with the same solid "thump" as the MBZ and I think the cabin is now at least as quiet as the MBZ.

Getting that solid door closing thump was relatively easy and doors are where I recommend people start because that solid door closing sound is always satisfying and noticeable, and you can work on one door at a time so your car is not disassembled for very long at a time. Installing CCF/MLV panels between the door sheet metal and the plastic door panels will block a lot of road noise coming from your car and the car or truck driving next to you. Unfortunately, properly fitting the MLV is harder and more time consuming than it looks (but much easier than doing the floor and cargo area). I posted my install pics and experiences on the doors and floor in this forum.

Probably 70% of what I needed to know to do this to my car is on the sound deadener showdown site. I also have the luxury of living near a business that specializes in sound proofing for aircraft and buildings, and was able to pick their brains since I was buying sound proofing material there.

 

I've searched about their radiant barrier but I haven't come across it here in Canada. It's for auto/rv use so it should work but again I've no experience using it...

Now for the list and their applications: (Note I'm here in Canada so some items may vary w/ yours)
-BQuiet Ultimate - Hood and directly behind the speakers in the door panels;
-BQuiet Extreme - Floor + any exposed metal area(s) around it especially where the firewall/wheel well bulge,
doors, under rear seat cushion/wall, spare tire well, rear quarter panels, hatch, license plate;
-Resisto multi-purpose waterproofing membrane - parts of the doors, as a double layer to some Ultimates esp. in the
spare tire well;
-Dominion Sure Seal Rubberized undercoating (spray and brush on variants) - Wheel wells, engine wall up to the
suspension wells as far as I can reach;
-Dominion Sure Seal Rubberized Rocker Guard spray on;
-Ultratouch Recycled Insulation - behind the rear quarter panel liners, the plastic separator/bin in the trunk, passenger
footwell/under glove box.
-Batting material - additional layer to the door plastic panels.
-Generic (but heavy) Rubber mat - applied as a decoupler in the spare tire well and floor panels.
-Door Seal weatherstrip material - applied to the door seams front and rear, and sides of hood.

As of yet, I would say I have only 1/3 of the undercoating done, still have to do under the car itself. Haven't applied the rocker guard coating as well. Slow but sure progress though

If you have any other concerns please feel free to ask or PM me. Hope this helps.

 

Just as I suspected, no "sound pillow" here. That's why I can clearly hear those tires above 25kph. Also, phoenixgreg sent me pics of the front quarter panels and man, they're bare! Hmmm... yes this is a target area as well...

 

Just an update... There's a "sound pillow" present but so small and thin in my opinion is hardly effective... Anyway, I got myself "SprayDead" liquid sound deadener, brushed a couple coats to those fender liners, some on the frame and that black plastic thing that separates the fender/door. This virtually muted tire/road noise at 60 and 100kph. Most of the noise (my next target) now is at the rear, which I believe is coming from the back window/hatch area. Will keep you guys posted...