Engine Cover?

[Ec0b00st]

Does this thing help or hurt?

In theory isn't it just heat soaking the shit out of the motor?

 

[6500rpm]

I can't speak for the SHO, but on most of the new generation of direct port fuel injected vehicles it's most useful purpose is to hide the clicking sound of the high pressure injection system. (They actually put noise dampening material all over the engines).