My $67 sound dampening / undercoating

[CTScott]

I have been meaning to paint the inside of the wheel wells since I bought my Yaris to get rid of the patchy look of some visible paint and some patches of seam sealer.

This Saturday I was planning on doing an oil change and figured I would do something with the wheel wells while I had it up on the lift. Doing a little research on coatings for the wheel wells, I found that Herculiner paint-on truck bed coating seemed to be a good choice. It is a urethane rubber based coating and is promoted as being for both truck bed protection and undercoating. For $67 for a gallon, I figured it was worth a shot. I wanted something that could be brushed on to avoid the mess of overspray.

Herculiner.jpg


I initially applied two coats to the wheel wells. I then got under the car and coated the floor pan. This morning it was done curing, so I took it out for a test run. The roads were wet and coated with sand from Saturday's snow storm. I was extremely impressed with the sound dampening that the coating provided.

Yaris - Undercoating.jpg

Yaris - Undercoating2.jpg

Yaris - Undercoating3.jpg

[Altitude]

Nice. Very jealous of your lift.

[fnkngrv]

Additional weight?

[enviri]

nice! I went with the more traditional fatmat at 1$/sq foot lol. I used only 50ft out of the 100 i bought, but plan on using a weee bit more when it warms up for the extremely noisy engine.

[CTScott]

Originally Posted by fnkngrv

Additional weight?

Negligible as compared with something like dynamat. An entire gallon weighs about 10 lbs and I only used about 1/3 of the gallon. I think I have enough left to do Crashy and my Tacoma.

[fnkngrv]

Originally Posted by CTScott

Negligible as compared with something like dynamat. An entire gallon weighs about 10 lbs and I only used about 1/3 of the gallon. I think I have enough left to do Crashy and my Tacoma.

wow...very nice! you should coat all over crashy...haha...that would be interesting

[Deathegg]

Originally Posted by fnkngrv

Additional weight?

Even if it weighed 50 lbs, it would have a negligible effect on...well, anything! I plan to do something like this soon, the road noise is bad on these cars. Thank God the engine is fairly quiet at speed.

Good job! I never thought of bed coating... It dries very hard then?

[mazilla]

Man, that lift is awesome...I'm drooling all over my desk!

[josh044]

Very nice - I'd love to do some sound deadening work at some point. It would be interesting to see someone do a before and after sound level test. I wonder what fixes have the most payoff.

[CTScott]

Deathegg - The Herculiner cures firm but flexible. It is urethane and is probably about half the durometer of roller blade wheels.

Josh044 - On Sunday night I was watching Wheeler-Dealers and they bought an old pickup to resell. The thing was loud as could be, so they bought a sound insulation kit for it. Before and after they did a sound level test and I sat there watching it going - Dang, I should have done that. I even have a good sound meter app for the iPhone.

[yarisugi]

Looks like $67 well spent. Did you have to pressure wash the dirt out before applying or just slapped it on?
Also curious about how much sound it helped block out. Damn your iPhone and that hindsight of yours! heehee.

[CTScott]

Originally Posted by yarisugi

Looks like $67 well spent. Did you have to pressure wash the dirt out before applying or just slapped it on?

I pressure washed it with Simple Green (and vacuumed all of the pebbles out of the leading edge of the rear wheel wells) before painting it.

[fnkngrv]

Originally Posted by Deathegg

Even if it weighed 50 lbs, it would have a negligible effect on...well, anything! I plan to do something like this soon, the road noise is bad on these cars. Thank God the engine is fairly quiet at speed.

Good job! I never thought of bed coating... It dries very hard then?

Not to burst your bubble, but you are incorrect. I can attest to that easily. 50lbs is 50lbs and will affect acceleration and braking. I see a very noticeable difference rolling on 15s as opposed to my 18s as well as whether or not I have my subwoofer box in the trunk or do not. Performing a spare tire delete even makes a difference. Every change you make to a car that is designed like the Yaris has an impact and you need to weigh the pros/cons. An example is going boosted and not only that, but whether or not you go SC or turbo when you gauge your FE. You very well trade FE for power.

[Deathegg]

Originally Posted by fnkngrv

Not to burst your bubble, but you are incorrect. I can attest to that easily. 50lbs is 50lbs and will affect acceleration and braking. I see a very noticeable difference rolling on 15s as opposed to my 18s as well as whether or not I have my subwoofer box in the trunk or do not. Performing a spare tire delete even makes a difference. Every change you make to a car that is designed like the Yaris has an impact and you need to weigh the pros/cons. An example is going boosted and not only that, but whether or not you go SC or turbo when you gauge your FE. You very well trade FE for power.

Wow, you must have a very sensitive backside if you notice the performance difference in 50 lbs. That's about 8 gallons of gas in the tank. If I take out the spare tire, my butt will not notice the difference. I would have to have a ScanGauge or similar instrumentation to tell the difference in MPG, acceleration, etc. Now, if you're talking about wheels and tires, that's a big difference in unsprung weight between 15" and 18". You'll notice that more than other weight reduction/increase.

[Viperoni]

Originally Posted by Deathegg

Wow, you must have a very sensitive backside if you notice the performance difference in 50 lbs. That's about 8 gallons of gas in the tank. If I take out the spare tire, my butt will not notice the difference. I would have to have a ScanGauge or similar instrumentation to tell the difference in MPG, acceleration, etc. Now, if you're talking about wheels and tires, that's a big difference in unsprung weight between 15" and 18". You'll notice that more than other weight reduction/increase.

Completely correct, you're noticing the unsprung weight difference, which coutns 4-10 times more than regular weight.

I can just barely feel the difference when I pull my sub box + amp out... and it's pushing 90lbs.


CTScott, do you have any vids of your mufflerless exhaust? Just wondering how it sounds.

[CTScott]

Originally Posted by Viperoni

Completely correct, you're noticing the unsprung weight difference, which coutns 4-10 times more than regular weight.

I can just barely feel the difference when I pull my sub box + amp out... and it's pushing 90lbs.


CTScott, do you have any vids of your mufflerless exhaust? Just wondering how it sounds.

It's actually the stock exhaust/muffler with a Toyota Thailand dual exhaust tip.

[Viperoni]

Originally Posted by CTScott

It's actually the stock exhaust/muffler with a Toyota Thailand dual exhaust tip.

I'm going to go ahead and delete my post, I just missed the forest for the trees lol.

[PHXDEMON]

Originally Posted by Deathegg

Even if it weighed 50 lbs, it would have a negligible effect on...well, anything! I plan to do something like this soon, the road noise is bad on these cars. Thank God the engine is fairly quiet at speed.

Good job! I never thought of bed coating... It dries very hard then?

50 lbs is noticeable in the yaris.