Radiator air venting through the hood

**Evolution1980** · 01-14-13, 02:02 PM

"Why let the hot air pass over the engine when you can evacuate it outside?" I think this is a great idea!
But I have a question that always comes to mind when I see cars with open hood scoops / vents / etc... "Where does the water go when it rains or you wash your car?"
On most cars(?), I reckon most of it splashes in the engine bay. This looks like a closed system, but I figure there has to be drain holes or something on the radiator core support.

**2VettesMike** · 01-14-13, 02:27 PM

Two benefits come to mind, one covered during the reveal last night.

Opening near the front of the hood increases downforce by reducing front end lift.
Secondly, getting the hot air out before it goes over the engine reduces heat soak into the intake manifold and air charge going into the cylinders.

Mike

**Tom73** · 01-14-13, 02:53 PM

Originally Posted by 2VettesMike

Two benefits come to mind, one covered during the reveal last night.

Opening near the front of the hood increases downforce by reducing front end lift.
Secondly, getting the hot air out before it goes over the engine reduces heat soak into the intake manifold and air charge going into the cylinders.

Mike

But what about air intake for the cabin? Normal way is to take in air at the cowl. Wouldn't that just put the hot engine air and fumes right in with the passengers?

Tom...

**Evolution1980** · 01-14-13, 03:11 PM

Originally Posted by 2VettesMike

Two benefits come to mind, one covered during the reveal last night.
Opening near the front of the hood increases downforce by reducing front end lift.
Secondly, getting the hot air out before it goes over the engine reduces heat soak into the intake manifold and air charge going into the cylinders.

Thanks, Mike. But my question was rhetorical in nature.

I meant for it to be posed as the "obvious" question. I have since gone back and tried to make it appear more that way.

Originally Posted by Tom73

But what about air intake for the cabin? Normal way is to take in air at the cowl. Wouldn't that just put the hot engine air and fumes right in with the passengers?

There are no fumes generated. All it's doing is taking fresh air and passing through a tunnel in which the radiator is in the middle. Fresh air in, fresh air out.

As for being heated, in another thread, I already conjectured that when the car is moving, the air coming out of the vent will be cooled enough that it's temp will be negligible by the time it reaches the windshield (top or bottom).

**Tom73** · 01-14-13, 08:24 PM

Okay, the air comes in the front, through the radiator, then out the hood. Where does the air for the engine intake come from?

**Evolution1980** · 01-14-13, 09:16 PM

Originally Posted by Tom73

Okay, the air comes in the front, through the radiator, then out the hood. Where does the air for the engine intake come from?

Really? You have to ask?

It's MAGIC!!! DUH!!!!

...Seriously, though, I hadn't thought of that. Without going back and inspecting some of the pics, I'm gonna guess there's a splitter somewhere in the front fascia or a smaller opening specifically for the air intake. Wouldn't surprise me if the engine sucked it's air from an intake split between the two sides of the front bumper.
*thinking out loud* That setup should(?) also make it easier to do a twin force-fed setup too! Twin turbos anyone???

**Tom73** · 01-15-13, 03:37 PM

Originally Posted by Evolution1980

I hadn't thought of that. Without going back and inspecting some of the pics, I'm gonna guess there's a splitter somewhere in the front fascia or a smaller opening specifically for the air intake. Wouldn't surprise me if the engine sucked it's air from an intake split between the two sides of the front bumper.
*thinking out loud* That setup should(?) also make it easier to do a twin force-fed setup too! Twin turbos anyone???

Seems that there would be four ducts on the front; one for cooling, one for the engine intake, and two for front brake cooling.

tom...

**David-F** · 01-15-13, 05:00 PM

I realy want to see what they are doing here if they are directing all the air coming from the radiator this could come back and bite them in a big way, just think about the Fero remember engine fires? there was not enough air flow over ther engine and things would get so hot coolant woulf burn if you look at rear engine cars thek have to vent air around the engine to help keep them cool one of the things against rear engine cars. Typical of front engine cars is air flow through the engine bay from the radiator opening, the Corvettes cut vents in the side of the fenders to vent air out the side instead under the car, but it not keep air from flowing through the engine bay. What is one of the problems with putting the trans in the rear of the car(C5, C6) lack of air flow around the trans they installed oil coolers which help but they still operate hotter then they would up closer to the air moving through the engine bay. If I had to make a guess this will not last long and they will make it just show in the future.

**AK Drop Top** · 01-20-13, 01:53 PM

You should check out the C6R program! Been doing this in the race car for quite sometime. Ever see the air box removed from the race car? It's huge, ya kinda wonder how they fit that box in there with the engine and keep the low profile. Engineered excellence for sure.

**jlakowicz** · 01-21-13, 12:44 PM

I had a Viper with open hood scoops. The hot air from the engine came out of the hood but if the windows were open the hot air flowed into the car. I don't know if this will happen with the C7.

**1analguy** · 01-21-13, 04:27 PM

I brought this point up the other night, right after the reveal. What happens to the warm radiator air that's supposedly flowing smoothly over the top of the car, when you remove the top? Someone posted back that the air would be nice and cool before it got that far. I still have my doubts...

**Evolution1980** · 01-21-13, 06:08 PM

Originally Posted by 1analguy

I brought this point up the other night, right after the reveal. What happens to the warm radiator air that's supposedly flowing smoothly over the top of the car, when you remove the top? Someone posted back that the air would be nice and cool before it got that far. I still have my doubts...

Originally Posted by Evolution1980

As for being heated, in another thread, I already conjectured that when the car is moving, the air coming out of the vent will be cooled enough that it's temp will be negligible by the time it reaches the windshield (top or bottom).

There are footnotes to my reference.
1) If the outside temps are 85°F or hotter, then you're probably gonna feel hot air regardless.
2) "When the car is moving" fast enough that you'd notice any cockpit turbulence in general.
3) Negligible being a keyword.

(Although I also realize that's an arbitrary point of reference...What is considered "negligible"?)

**1analguy** · 01-22-13, 07:32 PM

And, when you threw in the exhaust analogy, I was completely sold. But then came this:

Originally Posted by jlakowicz

I had a Viper with open hood scoops. The hot air from the engine came out of the hood but if the windows were open the hot air flowed into the car. I don't know if this will happen with the C7.

Which briefly caused me to doubt again. I wonder if what he was really feeling coming in through his windows was actually heat radiating off of the engine and coming out of the side vents...

**Evolution1980** · 01-22-13, 08:32 PM

Originally Posted by 1analguy

And, when you threw in the exhaust analogy, I was completely sold. But then came this:
Which briefly caused me to doubt again. I wonder if what he was really feeling coming in through his windows was actually heat radiating off of the engine and coming out of the side vents...

I would say you are correct. The air passing through the channel on the Vette, as I understand it thus far, is only passing through the radiator and that's it. Yes, the air coming out will be warmer than when it entered, but that's barely anything, temp-wise, respective to the hot air coming off the engine heads and exhaust manifolds.

**jlakowicz** · 01-25-13, 04:39 PM

I think it was hot air off the hood. I say this because in almost any weather when at a stop light you can see the wavy patters due to hot air when looking straight ahead over the hood vents. I have no proof that is the same air that came into the passenger compartment. It made in unpleasant to drive with the windows down even in moderate weather.