A flat painted sheet metal panel is not going to dissapate very much heat, so I can't buy the reduce heat reason, and that hood is sealed to both fenders and the firewall, so thats not it. I believe its a cost or sound issue, as the engineers mentioned in more than one interview the notion of maintaining a "tuner" sound. OR, it could be an interferance issue with the air cleaner box, as it sits pretty high. Actually, I don't mind the sound as much as its when people look at the noise in a parking lot, kinda like squealing brakes.

 

The hood insulation is going to hold the engine heat in not insulate the outside heat out. Also the way that the hood is sealed is such that it actually allows air flow to exit through the gaps. The lack of insulation and space between the hood & fenders is not the result of cost control or poor workmanship on the SS.

 

Thank's jx3, I Totally Missed That One

 

The purpose of hood insulation is sound insulation, not heat insulation. Yes, it can hold some heat in, but my argument is that a painted flat piece of steel is not going to be a big radiator of heat. Now if it was vented that would be different, but air flowing thru the engine area is going to pass off alot more heat than trying to pass heat thru a hood's sheet metal. The SS hood is also sealed by a one piece weatherstrip down both sides and across the back, mating to a flat bead all the way around the same area on the hood. The only place air would flow, would be in, thru the gap at the front above the radiator. I don't understand where you are referring to air flowing out the gaps.
Fact is the less expensive a car, the less chance it will have a hood insulator, and its because of noise abatement and cost, these guys leave out the smallest things to save a buck. Notice you don't have a light in the footwells? Well, Buicks, Caddies, and upscale Chevys do, just not Cobalts, HHR's, ect. I also never mentioned poor workmanship. The HHR is a great car for the money, an excellent value, especially the SS, but it doesn't mean you can't upgrade a few things for the better, which brings us back to the original question: Would adding the hoodliner from the LT quiet the SS down a bit?

 

Why not try it and find out and post the results?????

 

Waste of time and money from my perspective. But then I love the sound of open headers on a Big Block Chevy also.

Heck turn the radio up a notch and be happy :-)

 

Dynomat?

 

This is a liquid-cooled engine, not air-cooled. Engineers design the engine compartment to ensure that air is brought through the radiator then back under the car, not through the top of the compartment. There's no good reason why someone couldn't insulate the underside of the hood.

 

You ever wonder why GM designed the SS without a liner?

 

Actually, no, this is from the www.GMLAUNCHES.COM/chevy/hhrss/faq.asp

The turbocharger on this vehicle seems to make quite a bit more noise than some of the other turbocharged sport compacts in its class. Why is that?

The HHR SS is targeted for a tuner market, where waste gate noise is expected. The HHR SS design allows for more additional noise levels to meet this expectation.