Could a CF hood be heavier, what do they weigh ? A Z32 aluminium hood with insulation and trim is about 7.9Kg, where a Maxima of the time is about 19.4Kg. Only reason for CF is for looks or vents as BB said. But unless its needed its a shame to disfugure one of the most beutiful hoods ever made IMO.
if there is a cf hood produced via vacuum sealing process i think its called. then possibly as the thing that will weigh it down is the resin used to make the hood. It could be lighter. But most carbon fibre hoods are produced with a layer or 2 of carbon fibre then just a bunch of fibreglass below, that will most likely weigh the same as the aluminium hood.
Having held the two back to back the carbon hood on my car does not feel heavier than stock. I will weigh them one day to confirm.