Hood Insulator Question

[DWC]

Why is it that some Corvettes, particularly C-5s and older C-3s, have hood insulator blankets and C-4s do not. The only C-4s that received hood insulator blankets from the factory were those being shipped to Canada.

GM makes a hood insulator blanket for C-4s but they must be purchased and installed by the owner.

What is the purpose of the insulator blankets? Are they to protect the fiberglass hood and paint from the heat generated by the motor? What is their purpose?

[Redbob]

The hood insulation for the Canada C4's is for reduced exterior noise, per Sae J986.
It will also give a VERY slight reduction in interior noise. You'll need good ears to pick this up, though.

Regards,
R

[88canadianvette]

my 88' doesnt have a hood insulator..i cant even find the mounts for any insulator. and it is a canadian car.

Why would you want to lower the noise of the engine!!!!

VRROOOOOOMM VROOOOOOOOOOOOOM!



Fiddler

[Redbob]

Originally posted by Fiddler's Gold
Why would you want to lower the noise of the engine!!!!

VRROOOOOOMM VROOOOOOOOOOOOOM!



Fiddler

To pass the noise test.
So GM can sell the car.
Unlike the ZR-1, which had a "defeat" algorithm in the engine control software that detects when a noise test is being performed (constant 30 MPH for 'x' seconds, followed by WOT) and dials back the horsepower by about 50%!

Regarding interior noise, the hoodblanket reduces the annoying high-frequency stuff (noise stuff, that is) that comes off the valvetrain.
Actually improves sound quality, unmasks the low-frequency rumble that we know and love.

My setup is completely UNMASKED!!! VRRRROOOOMMM!
Plus we don't have any smog or header restrictions in LA so I guess I didn't know that there was a problem with it.

Whatever soothes your ears!

Fiddler

[Redbob]

My apologies for posting a technical reply.

No offense meant to you.

Sincerely,
Fiddler