Hood insulation... Is it necessary?

[Audone]

One corner of my hood insulation is peeling away and looks like crap, can I just take off the whole thing without worrying about heat transfer to the hood? (ie. paint)

[svirk2]

It also helps with sound deadening, I wouldn't remove it

[yObOyGeo]

its a fire blanket, in case your engine bursts into flames, the plastic screws would melt and the blanket" would fall on it

[seanj130]

its a fire blanket, in case your engine bursts into flames, the plastic screws would melt and the blanket" would fall on it

I have never heard anyone else say this besides my friend (Audi tech) and myself. Bravo.

It has NOTHING to do with sound. It is strictly for fire.

[B6JoeS4]

Take it off and throw it away. No, your paint won't bubble because of the heat.

It's going to stop the flames? Please, you have bigger problems such as the rubber fuel line to worry about, and the 10L of oil. And the other fluids, and the battery.

[Blackstallion]

Take it off and throw it away. No, your paint won't bubble because of the heat.

It's going to stop the flames? Please, you have bigger problems such as the rubber fuel line to worry about, and the 10L of oil. And the other fluids, and the battery.

Never fear..joes here!

[dparm]

Heat damage? Definitely not. Have you ever touched the hood of your car after the car sits in the mid-day summer sun for a few hours?

[seanj130]

Take it off and throw it away. No, your paint won't bubble because of the heat.

It's going to stop the flames? Please, you have bigger problems such as the rubber fuel line to worry about, and the 10L of oil. And the other fluids, and the battery.

Light a small fire, then go throw a blanket/ towel on it. When there is a small flame, the material can surpress the fire before it gets any larger, or before it hits the fuel line or 10L of oil. Do you think that Audi would waste time/money/research to add something to a car, especially when they sell 1,000,000 cars a year? I think not.. Not to mention all the VW's that it comes on.. Or Toyotas.. Or hondas.. It MUST do SOMETHING..

[B6JoeS4]

So you want to save your car that just caught on fire by containing the flames? I'd let it burn, no need to be a hero.

Do you know for a fact that the cover is designed to contain flames? I'd bet not. I would say its there for sound insulation more than anything else.

[BillyT]

I believe those things generally serve both purposes of sound deadening and flame suppression. But I don't think removing it is a big deal at all.

[CDN_S4]

I believe those things generally serve both purposes of sound deadening and flame suppression. But I don't think removing it is a big deal at all.

ditto - x2

[65vetteC6]

So you want to save your car that just caught on fire by containing the flames? I'd let it burn, no need to be a hero.

Do you know for a fact that the cover is designed to contain flames? I'd bet not. I would say its there for sound insulation more than anything else.

^this is my car caught on fire I wouldn't want it back. Let it burn.

[auxnbus]

Light a small fire, then go throw a blanket/ towel on it. When there is a small flame, the material can surpress the fire before it gets any larger, or before it hits the fuel line or 10L of oil. Do you think that Audi would waste time/money/research to add something to a car, especially when they sell 1,00,000 cars a year? I think not.. Not to mention all the VW's that it comes on.. Or Toyotas.. Or hondas.. It MUST do SOMETHING..

The thing is.... it's going to take ALOT more than a 'small flame' to melt those plastic tabs enough to drop the sheet and smother the flame. By the time the fire has gotten big enouigh and hot enough to melt all of the tabs you will have other things to worry about.

My take on it? Purely sound deadening. I took mine off and was rewarded with a bit more noise from the engine.

[emcaha]

I can tell you the main purpose of the insulation is for fire supression, sound deadening is secondary. If you look on some cars you'll notice they have foam-type insulation on the hood, my Corrado has this for example, this is meant to melt in the event of a fire and choke it out by smothering it. The foam is in sections too not over the whole hood so I doubt it helps much with noise (not that I'd want it to with that blower singing).

How effective this is is a whole different story. I'd guess it's not meant to protect the car as it is protect the passenger/driver and give them some more time to get out of the car safely. Could also be some kind of goverment safety regulation since it seems like all cars have this in some way or another.

[yObOyGeo]

Really guys ? Sound ? Heat ? Keep it cozy on cold nights ? Jeez

[Maddog3xx8]

if your shit catches fire your most likely already at a total loss! just get out of the car and watch that mother ****** burn! that shitty blanky isn't going to do shit!

Audi should of left that out during the build and invested the few extra dollars on the chain guides!

[BillyT]

I took mine off and was rewarded with a bit more noise from the engine.

What kind of noise? A tough meaty V8 growl or just more of that annoying whine sound?

[BillyT]

Everyone's commenting on the engine fire damaging your car when I'm sure the real purpose is making sure it doesn't burn your freaking house down while sitting in the garage over night.

"OMG MY AUDI'S ENGINE IS BURNT!!!! But my family all woke up alive this morning with our house intact."

[auxnbus]

What kind of noise? A tough meaty V8 growl or just more of that annoying whine sound?

Engine intake... good noise IMHO. It's only a slightly audible difference though.

[dparm]

You'll hear a bit more engine noise. It's not going to change any of the intake harmonics or whatever you want to call them...

[BillyT]

I wonder what it weighs too.

[auxnbus]

I wonder what it weighs too.

Not a lot... only a couple pounds.

[seanj130]

Everyone's commenting on the engine fire damaging your car when I'm sure the real purpose is making sure it doesn't burn your freaking house down while sitting in the garage over night.

"OMG MY AUDI'S ENGINE IS BURNT!!!! But my family all woke up alive this morning with our house intact."

Well said.. Glad someone can look at the whole picture.

[dolphin B6 S4]

If it's off in the garage I think theres much less of a chance of it catching on fire as compared to sitting at idle in traffic.

[erode]

It also helps with sound deadening, I wouldn't remove it

It was probably just because I was an 18 year old punk, but removing the hood insulation was one of my favorite mods to my E36 M3. Suddenly I could hear all the thousands of dollars I had poured into that engine. As an adult, I don't think I would like it.

[BillyT]

If it's off in the garage I think theres much less of a chance of it catching on fire as compared to sitting at idle in traffic.

I've actually watched my parents old station wagon burn to the ground and it didn't happen sitting in traffic with the coolant flowing and fans blowing. It happend about a half hour after parking it straight off a long drive coming back from a camping trip. Luckily it wasn't parked in the garage.

[beemercer]

Do you know for a fact that the cover is designed to contain flames? I'd bet not. I would say its there for sound insulation more than anything else.

fuck the blanket, I put out an engine fire on the A6 with 4L of coke on the way to waterfest 2011 lol

[BillyT]

As long as your garage is not attached to your house. :)

[LOUDERPLEASE]

what

youse are seriously living in the belief that the hood liner will fall onto the engine and put the fire out

ahhhhh-HAHAHAHAHAHHAHAH!!!!

[BillyT]

what

youse are seriously living in the belief that the hood liner will fall onto the engine and put the fire out

ahhhhh-HAHAHAHAHAHHAHAH!!!!

The under hood insulation from 20 vehicles were tested using a cone calorimeter
to assess their fire resistive/burn properties. Including the repeat tests a total of
27 tests were performed. The cone tests were conducted according to the
procedures in ASTM E 1354-03 standard. The mounting clips for each of the
liners were also tested to determine the temperature at which they would melt,
disengaging the liner from the vehicle hood.
Of the insulating under hood liners tested 5 did not ignite. An additional 7
insulation samples that did ignite exhibited a short time to flameout with
comparatively low peak heat release rates. These samples with the inclusion of
the non igniting samples show the most potential for smothering an engine fire.
The Cone Calorimeter testing indicated that the application of a metal foil to the
engine facing side of an under hood insulting panel can significantly enhance the
fire resistance of an insulating material by preventing ignition.
If an under hood insulation panel is to smother a fire the mounting clips affixing
it to the hood must disengage from the hood under high heat conditions of an
engine compartment fire. The mounting clips for the under hood insulation from
the twenty different vehicles tested disengage from the supporting structure at
temperatures ranging from 133 °C to 268 °C. Furthermore the results seemed to
indicated that the design of the mounting clips may have an influence on the
deformation pattern and the temperature required for the insulating sample to
disengage.
Given that fire resistant under hood insulating panels were identified amongst
the small sample of vehicles examined, the possibility of the panels acting as a
fire blanket and smothering and engine fire is feasible. However, the
effectiveness of such a system can not be determined strictly from the component
tests that were performed. Ultimately, the typical temperatures of an engine
compartment fire need to be lower than the flaming temperature of the
insulation and higher than the melting temperature for the mounting clips.
Simulated engine compartment fires are needed to determine the actual
effectiveness of a fire resistive panel at smothering a fire.

http://www.mvfri.org/Contracts/Final...Insulation.pdf

[LOUDERPLEASE]

ahhhhh-HAHAHAHAHAHHAHAH!!!!

[troyguitar]

It's purely designed to be a sound insulator. I'm an engineer at an OEM supplier that makes those things along with other acoustic and thermal solutions.

Insulators in the engine bay are required to not burn for more than 38mm or 30 seconds when exposed to a flame for 15 seconds, but they are not put in the car to suppress fires. They are merely allowed to be put in the car because they won't make a fire any worse.

That polyurethane foam actually puts out some very nasty smoke even though it doesn't burn very much.

[BillyT]

It's purely designed to be a sound insulator. I'm an engineer at an OEM supplier that makes those things along with other acoustic and thermal solutions.

Insulators in the engine bay are required to not burn for more than 38mm or 30 seconds when exposed to a flame for 15 seconds, but they are not put in the car to suppress fires. They are merely allowed to be put in the car because they won't make a fire any worse.

That polyurethane foam actually puts out some very nasty smoke even though it doesn't burn very much.

This seems to be saying otherwise.

http://www.mvfri.org/Contracts/Final...Insulation.pdf

[event]

This seems to be saying otherwise.

http://www.mvfri.org/Contracts/Final...Insulation.pdf

From what I read that test only checked the resistance of the insulators and clips, nothing more. It even states that the smothering capability is only "feasible" and "cannot be determined" with the approach they took. How is that saying otherwise to what troyguitar said?

[LOUDERPLEASE]

ok so - riddle me this.

when the hood is closed - the liner is practically pressed down to maybe a couple of fingers distance between the sheet metal above, and the raging inferno below. The clips *eventually* melt.....the liner drops.....a little bit.....

sorry but the whole concept / visual of the thing acting like some sort of superman-cape miraculous fire blanket falling from the sky and saving your S4's from a fate worse than plastidip is really making my day!

[BillyT]

Feasible and inconclusive to you says otherwise?

It clearly refutes your statement that "It's purely designed to be a sound insulator", whether super effective or not.

[event]

It clearly refutes your statement that "It's purely designed to be a sound insulator", whether super effective or not.

Wow, you really just read and take in what you want huh?

[BillyT]

Wow, you really just read and take in what you want huh?

You're the one pretending that they went to all that effort to do fire tests on 20 cars complete whith a section on the plastic clips they say are meant to melt off... on a device that was... "purely designed to be a sound insulator".

[BillyT]

And the word "sound" shows up in that study exactly zero times.

[BillyT]

it was suggested by both Ford and Toyota dealerships that the under hood insulation in their F-150 and Sienna respectively were designed to descend and smother an engine compartment fire

Straight from that study.