Adding a hood scoop?
 

Would adding a hood scoop with the opening facing the windshield cause a significant decrease in MPG's? I have a 1995 acura integra that gets a pretty hot engine and wanted to add a scoop but not if it's gonna severely hurt my fuel economy.

There is probably an issue with the cooling system that should be dealt with first. Adding a hoodscoop would just be a bandaid.

agreed, might be better to get a coolant fush, or find out what's causing the high heat condition

Does it get higher then have way on the temp gauge?

No over heating issues. It just gets hot thats all. And I was planning to block off the front of the car for better aerodynamics but if a hood scoop hurts that then there isn't a point. Could I just get answers on the hood scoop question, not the car over heating question please.

In theory, I would think it would hurt your FE, as it would create a lower pressure going into your intake (because it's in a wake) Now, how much it would hurt I don't know. I've wondered myself about the benefits/drawbacks of a forward-facing hood scoop--it'll probably hurt aero but the ram air should help the engine. A rear-ward facing hood scoop would basically give you negative ram air I would think.

Cowl induction
 

Look up "cowl induction". There is a high-pressure area at the base of the hood on most cars (AFAIK); a hood scoop facing rearward at the rear of the hood will take in air from that high pressure.

I have no idea how it will affect the aerodynamics of the vehicle, compared to a forward-facing scoop on the front of the hood or no scoop at all.

Check your coolant/radiator thermostat. I had to replace mine last year. It was stuck halfway open, leading to long warmups and then running hot once it was warmed up.

get some exhaust header wrap and wrap your exhaust. That will reduce under the hood temps a little.

Yes I'm aware of cowl induction but most of those are for performance. I just want a little cooler air into the engine. The air wouldn't even hit near the intake at all more like the top of the block. I would just like to know if or how bad it would mess up the aerodynamics.

I guess I was wrong about the low pressure region. I didn't know about cowl induction (I'm always learning). And I misunderstood you--I thought you were talking to about connecting the hood scoop to your intake, not just into the engine compartment.

I am considering doing exactly the same thing. I seriously doubt whether you would notice any decrease in FE. It would also vent some of that hot air under the hood; and maybe give your radiator a little better cooling. There's only one way to find out though. Just do it and see what happens. You might surprise alot of people.

Actually, since its a high pressure zone, air will come into the engine bay at the hood/windshield transition point. This means more air goes under the car to an aerodynamically dirty underside. Thus, the aero is worse. Also, I do recall reading a while ago people using spacers to prop up the back of their hood. Some actually saw worse cooling with the hood spaced up. The airflow into the engine bay increases the pressure inside the engine bay. This in turn reduces the flow through the radiator and reduces the cooling capacity.

So your saying it would be a bad idea?

What you could try is to seal the bumper to front of the radiator, so the openings have to push the air past the radiator. That should help cooling some and when you are at it straighten out any bend fins on the radiator, they make a tool to do that but a cheap comb like they give kids on picture day will work if you cut the ends off.