Does under-hood sound insulation actually work? Testing says...

[BudgetBronco]

Based on my testing, the answer is yes and no.

It DOES reduce sound levels when the Bronco is idling, as measured outside the vehicle
It DOES give the hood a more finished look
It DOES likely make it easier to clean the underside of the hood, keeping mud and crud out of the recesses in the bracing

But, it does NOT reduce sound levels inside the cabin when revving the engine or when driving on the highway. That is what my testing revealed with the 2.3L engine and manual transmission with hard top. Here are the results of my tests, and below that a link to the full video if you are interested.

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[ctandc]

Thought I'd add to this - if you shop online Ford Parts sources, you can get the OEM Ford insulator pad for a tick under $80 SHIPPED.

Ford Part# M2DZ-16738-A

You need the retainer clips (I haven't checked how many yet). The Ford PT#w705002s300.

Great thing about Ford (and most every other Auto manufacturer) they use fasteners that are already in their parts system whenever they can - so these fasteners work on all kinds of different vehicles. This means the aftermarket normally already has an equivalent part out there. I can tell you from personal experience, high-volume body shops don't pay $3-6 per trim clip. They buy in bulk.

A quick search found these (I can't personally verify fit)

https://www.amazon.com/Lincoln-Insu...ix=w705002s300,aps,276&sr=8-2#customerReviews

Normally I measure the clip in question and I hit up a auto body clip / fastener supplier, such as:

https://www.clipsandfasteners.com/default.asp

There are several others. You can also spend $20-30 and buy a kit with a LARGE assortment of Manufacturer associated trim / molding clips.

The other thing, and if you explained it in the video I apologize, I think most people are thinking "16% reduction in decibels at idle? That's not worth $80."

You can't think if decibel reduction / increase as a linear progression or regression. For example - if you reduce the sound of the engine running by 10 decibels - in reality, to your ear, that is a MUCH bigger reduction that what it seems on paper.

Logarithmic scales are weird, just saying.

As for engine noise reduction in the cabin, I'd be curious to see pictures of upper trim levels (like OBX or LUX models) and the firewall insulation they have. Here's a pic of what Ford Parts Catalogs list:

HTH

 

[BudgetBronco]

Thought I'd add to this - if you shop online Ford Parts sources, you can get the OEM Ford insulator pad for a tick under $80 SHIPPED.

Ford Part# M2DZ-16738-A

You need the retainer clips (I haven't checked how many yet). The Ford PT#w705002s300.

Great thing about Ford (and most every other Auto manufacturer) they use fasteners that are already in their parts system whenever they can - so these fasteners work on all kinds of different vehicles. This means the aftermarket normally already has an equivalent part out there. I can tell you from personal experience, high-volume body shops don't pay $3-6 per trim clip. They buy in bulk.

A quick search found these (I can't personally verify fit)

https://www.amazon.com/Lincoln-Insulation-Retainer-Diameter-Qty-15/dp/B07FTSK8P5/ref=sr_1_2?crid=33G8NXQ038CEH&keywords=w705002s300&qid=1652789529&sprefix=w705002s300,aps,276&sr=8-2#customerReviews

Normally I measure the clip in question and I hit up a auto body clip / fastener supplier, such as:

https://www.clipsandfasteners.com/default.asp

There are several others. You can also spend $20-30 and buy a kit with a LARGE assortment of Manufacturer associated trim / molding clips.

The other thing, and if you explained it in the video I apologize, I think most people are thinking "16% reduction in decibels at idle? That's not worth $80."

You can't think if decibel reduction / increase as a linear progression or regression. For example - if you reduce the sound of the engine running by 10 decibels - in reality, to your ear, that is a MUCH bigger reduction that what it seems on paper.

Logarithmic scales are weird, just saying.

As for engine noise reduction in the cabin, I'd be curious to see pictures of upper trim levels (like OBX or LUX models) and the firewall insulation they have. Here's a pic of what Ford Parts Catalogs list:

HTH

Good post, thanks for adding that. I will make a few notes:
- Yes on the db scale, somebody made the same comment on YT, and that is a good point. In fact I just went to my YT channel and pinned that comment to the top, so hopefully others will see it. I honestly don't know if the free smartphone app I used is truly measuring in decibels. Either way I can very safely say based on my experience and testing: there is a noticeable improvement in noise outside the vehicle, but there is negligible improvement inside the cabin, as any small reduction in engine noise is offset by wind noise and tire noise. I think you will need some firewall insulation in order to see gains inside.
- If you buy the insulation from Ford, you will need 13 of the 'christmas tree' fasteners. I would definitely buy on Amazon and save a lot of $, they need to fit in a 1/4 inch hole, something like these should work: https://amzn.to/3lnN9rE

 

[soupcansam]

Based on my testing, the answer is yes and no.

It DOES reduce sound levels when the Bronco is idling, as measured outside the vehicle
It DOES give the hood a more finished look
It DOES likely make it easier to clean the underside of the hood, keeping mud and crud out of the recesses in the bracing

But, it does NOT reduce sound levels inside the cabin when revving the engine or when driving on the highway. That is what my testing revealed with the 2.3L engine and manual transmission with hard top. Here are the results of my tests, and below that a link to the full video if you are interested.

How has the hood insulation that you bought held up? I'm considering doing this to my Bronco but don't know (or if it matters at all) whether I should go OEM or something from Rongtaod or similar aftermarket?

 

[BudgetBronco]

How has the hood insulation that you bought held up? I'm considering doing this to my Bronco but don't know (or if it matters at all) whether I should go OEM or something from Rongtaod or similar aftermarket?

It has held up perfectly, looks as good as the day I installed it. As mentioned in my video, limited benefit on sound reduction, but it does give a nicer finished look.

 

[soupcansam]

It has held up perfectly, looks as good as the day I installed it. As mentioned in my video, limited benefit on sound reduction, but it does give a nicer finished look.

Yea, that's pretty much why I wanted it. And, the noise outside the car at idle as I live in an apartment complex and don't like disturbing others. But, this answers my questions perfectly, I'll go ahead and get the one you got. Thank you!

 

[choppersean]

Based on my testing, the answer is yes and no.

It DOES reduce sound levels when the Bronco is idling, as measured outside the vehicle
It DOES give the hood a more finished look
It DOES likely make it easier to clean the underside of the hood, keeping mud and crud out of the recesses in the bracing

But, it does NOT reduce sound levels inside the cabin when revving the engine or when driving on the highway. That is what my testing revealed with the 2.3L engine and manual transmission with hard top. Here are the results of my tests, and below that a link to the full video if you are interested.

With all due respect to the OP, my response is critical to the sound/noise aspect. If you want to use this as a shield for keeping shit out of the brace cracks and creases, well then knock yourselves out. The "more finished look" argument is subjective. As a sound attenuator, it is a waste of money.

What is meant by the footnote "NOT CALIBRATED TO TRUE DECIBELS?" I question the credibility by reading that fine print.

Also, if the numbers are supposed to be on a decibel scale, you realize that DBs are on a logarithmic scale and so the "DIFFERENCE" really couldn't be calculated as you have done here. Based on the IDLE numbers you have, the difference is actually that the "AFTER" is like 3.5x the strength of sound.

Lastly, this is my opinion that this is a HUGE waste of money given your results. Since Idle is the ONLY apparent difference.........and how often are you going to be at idle in a garage?..........but for comparison, normal conversation can be 60 to 70 decibels. I'll spend my money on other more impactful things for my bronco but trying to silence something that is already reasonably quiet just seems like a waste.

 

[BudgetBronco]

With all due respect to the OP, my response is critical to the sound/noise aspect. If you want to use this as a shield for keeping shit out of the brace cracks and creases, well then knock yourselves out. The "more finished look" argument is subjective. As a sound attenuator, it is a waste of money.

What is meant by the footnote "NOT CALIBRATED TO TRUE DECIBELS?" I question the credibility by reading that fine print.

Also, if the numbers are supposed to be on a decibel scale, you realize that DBs are on a logarithmic scale and so the "DIFFERENCE" really couldn't be calculated as you have done here. Based on the IDLE numbers you have, the difference is actually that the "AFTER" is like 3.5x the strength of sound.

Lastly, this is my opinion that this is a HUGE waste of money given your results. Since Idle is the ONLY apparent difference.........and how often are you going to be at idle in a garage?..........but for comparison, normal conversation can be 60 to 70 decibels. I'll spend my money on other more impactful things for my bronco but trying to silence something that is already reasonably quiet just seems like a waste.

Hey everybody is entitled to an opinion and I fully accept that with any post/video I am inviting feedback.

That said:
- Agree, 'finished look' is subjective
- By 'not calibrated' I meant I just used a free app on my phone to measure. Not a calibrated scientific measuring device. So when my phone app was reading 69.2 decibels, I have no way of knowing if that is accurate or not. I am not Project Farm (that guy has AWESOME measuring devices!)
- I do stand by my overall assessment: there is some noise reduction at idle when listening outside the vehicle. But from inside the vehicle the difference is negligible. So make any purchasing decision based on that info, and I do believe my data is helpful from that respect of helping others with this decision.
- Honestly I did forget that db is a log scale, it has been a looooong time since I studied that

 

[doyouglas]

I think more importantly it controls heat under the hood. Protect your paint by keeping the hood cool and protected from the heat of your engine. I think for 70 bucks it's worth it and is not a waste a money. Even if it lowers the sound by a small fraction, controls heat by a small fraction, and looks good. Why not?

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