what would be better, getting cool air into the carb, or a vented hood that lets hot air out of the engine compartment?

 

Both.

 

Werd....but cool air in and blocking surrounding heated air from going in also is the way to go for cheapness. Build an aluminum or fiberglass box around the carb and duct it with 2 3" or 4" hose....what carb by the way...xtreme rotaries in AUS have a nice fiberglass bonnet for IDA's.

 

Jaime,
The custom IDA cold-air intake from Auz is a junk IMHO. I installed one in my buddy's red 1st gen (Dice) and it was too restricted. Very quiet as you cant hear the carb sucking air.

 

45 dcoe

 

Cool air to the carb is good,but can be overdone too.
Effective,sealed ram air will screw with the carbs metering ability since it raises manifold pressure through the venturi.Also,you run the risk of carb icing if its cool and moist outside.My Yaw carb used to freeze up solid after only a couple miles on the freeway.I had an aluminum duct from the pass. side turn signal hole to the stock aircleaner.Not high tech or sealed at all,but,even in well above freezing temps,on the highway the primaries would ice and the engine would stall.

Hot air out is always a good thing.Plus,any air you route out the engine bay above or beside the car(hood/fender vents),will increase high speed stability since there is now less air going under the car,trying to lift it up.