Yep! Your intake box if your hood is adjusted properly will be right against the hood. It may rub.

 

In reading the posts from the link provided I saw a lot of different (and some strong) opinions on the question of heat soak, use of the insulation for sound deadening, a suggestion that it is valuable as a fire retardant, and one (possibly informed?) opinion below:

Who knows for sure and I hope I haven't opened that can of worms back up. Maybe we should merge this post into the original and let it RIP?

 

Oops I see I was late in posting the same message. Should have spend more time reading and refrain from stopping for a coffee in the middle of my postings (or learn to type faster).

 

I bought my HHR SS as a preowned vehicle and it came with hood insulation. Don't know why it's there or if it was a mistake at the factory or an add on by the previous owner. After reviewing some of the opinions from all of the knowledgeable and informed members, I became concerned.

As someone who deals with thermodynamics on a daily basis at my occupation, I ruled out the issue with heat containment/dissipation/transfer properties, but considered the possibility of sound resonance. But this is based upon my own experiences in the field and others are certainly welcome to their theories.

My concern was stress or chafing on the airbox, although I see no indication of it on the insulation or airbox at present.

As a static test, I placed pieces of painter's tape glue side up on all 4 top corners of the airbox and slowly but firmly closed the hood. Upon opening it, the tape was still on the airbox, undisturbed. I then tried the same test using some of my kid's modeling clay substitute, keeping the blobs relatively flat sticking to the top corners of the airbox again. Upon opening the hood, there was no evidence of contact. Maybe if I can get my hands on more of this stuff, I can determine what the approximate distance actually is. I'll follow up.

I got to thinking about what other vehicles with similar powerplants have in regard to the use (or lack of) hood insulation, so I checked pics on various websites. I posted the sites, but you would have to dig a little to see the pics that you want. I came to this conclusion:

The Pontiac Solstice is equipped with hood insulation
The Saturn Sky is equipped with hood insulation
The Cobalt SS is equipped with hood insulation


http://www.solsticeforum.com/photopost/
http://www.skyroadster.com/photopost/
http://cobaltss.net/gallery/
http://www.autoblog.com/photos/em-20...-turbo/460578/

It is my hypothesis that the most plausible theory is that of sound enhancement and possibly cost savings. In my opinion, I would not remove it if you have hood insulation, but I wouldn't add it if you don't.

 

Very nice analysis and nice logical conclusions. My only issue with cost savings is they eliminated it for the SS model only. If they REALLY wanted to save money they would have done it across the line not just on the relatively limited production SS. My guess from your work then is sound enhancement which you stated as the primary reason.

 

The bottom line is it is not factory for a reason and if the benifits out weight the issues GM would have put it on.

Some times it is a very simple reason but still a reason.

 

whatever....and more points to ponder....what is the big peices of insulation for that are stuffed in the rear of the front fenders ??? i hope they don't hold moister/water.....would they be there for the same reason that there is , or is not insulation under the hood ???

 

Often these pads are to prevent heat and noise mostly noise. THey are water resistant.

 

Might note the air box is different on the HHR and is close to the hood. THis may be why we don't get the padding. All the other LNF engines have different air boxes.

 

The new Mustang has a sound tube (or something like that) which connects the engine compartment to the passanger area so you can hear the motor louder. So it is conceivable that Chevy assumed people buying the SS would like to hear engine sound.

That said, I removed my liner several years ago. First, I show the car and it looks much better without it. Second, I prefer not to trap the heat under the hood. Third, even though it is only 3 pounds, it is positioned pretty high above the wheels which certainly wouldnt help the handling. Sure, it may be petty, but a pound here and a pound there...