Removing the windshield cowl for better cooling? Thoughts?

[M-Sport fan]

^^^He is LONG GONE from this site (and I won't comment on WHY that is, or anything else).

 

[JDG]

^^^He is LONG GONE from this site (and I won't comment on WHY that is, or anything else).

@the duke is still here though and fairly active. Let's keep this on topic as I am also curious.

 

[TyphoonFiST]

Curious about what your results were? Did you do any testing with before/after engine bay temperatures? Happen to stick any string and tape to the cowl area with a camera (full ford gt style) to see what the air was doing as @the duke cautioned on?

SourSkittle is long gone my fellow Fister....The DHM debacle took him and them with the fiasco.

 

[The Cuzi]

@the duke is still here though and fairly active. Let's keep this on topic as I am also curious.

Agreed. I also vote to keep topic alive. Not keen on drama but would like to know more about airflow and fluid dynamics if @the duke can help. If not, I might pick a sunny weekend and rip it off myself for testing.

 

[PunkST]

I wouldnt pull that plastic. Its better to lift the backside of the hood or get a vent near the back side where its hottest. ( Maybe a proper cowl hood??)

 

[TyphoonFiST]

I wouldnt pull that plastic. Its better to lift the backside of the hood or get a vent near the back side where its hottest. ( Maybe a proper cowl hood??)

NACA duct time!

 

[AZSP33D]

Cooling airflow happens due to differential pressure in front of the radiator compared to the pressure behind... and the resulting airflow. Increasing the air pressure behind the radiator with cowl induction should reduce cooling effectiveness. Just some basics, and lots of references to this in books on aero, specifically on race cars as there’s lots of CFD data showing the high pressure zone there.

 

[PunkST]

Unless you grab that air and funnel it elsewhere 😉.
Air is dumb. You have to make it go where you want it too.

 

[PunkST]

Best idea i can come up with RN is to drill a hole in the lower cowl section. Then duct air down from there to blow on the center of the turbo. The HVAC pulls air from between the two cowl halves, so you might get some engine smells unless you figure out filter of some sort. Best thing about this idea is that it looks stock on the outside.

 

[The Cuzi]

Cooling airflow happens due to differential pressure in front of the radiator compared to the pressure behind... and the resulting airflow. Increasing the air pressure behind the radiator with cowl induction should reduce cooling effectiveness. Just some basics, and lots of references to this in books on aero, specifically on race cars as there’s lots of CFD data showing the high pressure zone there.

Makes sense. Not looking to pipe air in, but pull air out further amplifying the low pressure area.

 

[Matt.bo]

So haven’t had the cowl on my car for about 6 months because I was too lazy to put it back on. I forgot it wasn’t on and went through a car wash.... Obviously that was moronic but what’s done is done and now I can’t find the issues that I believe the water caused. So in all honesty, if you’re just using the car for the track, do what you gotta do. But for daily driving, I would leave the cowl on. Modify how you please though, some interesting ideas in here

 

[theblue]

you want to seal the back edge of your hood from the engine bay or it crates aerodynamic lift on the front end of the car. that's why all modern cars are like this. as said, this will bring air into the bay, not out.

 

[PunkST]

^that is only true if you do nothing to channel the air where you want it to go. Most of the vented hoods really dont do squat at high speed.

 

[the duke]

I know very little about fluid dynamics, but this seems to make sense. I could see the negative space between the hood and the windshield creating a burble. I was thinking of doing something similar though on a smaller scale versus removing the whole top cowl. I was thinking of putting a series of a few small pipes/tubes through the cowl area (from the engine bay through the bottom cowl through the top and protruding slightly to avoid water and drainage issues).

I am running the 2J Cowl Intake so the OEM intake snorkel is pushing air into an empty space in the engine bay. My thinking/theory is that a small 'exit' through the cowl would allow air entering from the snorkel to pass through the engine bay and out over the windshield. Do you think something like this could produce a flow of air through the engine bay and over the windshield vs down and under the car?

Honestly you're overthinking this. The car is not that sensitive to airflow at least something as small as that inlet, this isn't a full fledged race car or F1 car. The air entering the engine bay would likely slam into the engine/everything and disperse around. At that point as pointed our above you're just introducing more air and essentially creating drag. You could try to create an exit somewhere, but that doesn't mean the airflow is there. Proper race cars are ducted for this very reason. The air inlet runs off of the high pressure from the front of the car providing a wall and the resulting engine intake providing negative pressure (the turbo pulls in air).

Here's what you'd really want with that idea. There is an inlet in the bumper to the radiator . Both the lower opening and the twin openings in the center.

The inlet passes air over the radiator fins to provide thermal dissipation and then a duct/ramp behind the radiator creates a path for the hot, energized (and expanding) air to diffuse into. This path ultimately exits via a vent through the hood.
(Not an Integra, but here's an example of proper ducting)

Here's the hood vent. Notice it's kinda forward, as there's only so much room to before you run into the engine block.

This is over-simplified however you get the idea.

 

[the duke]

Best idea i can come up with RN is to drill a hole in the lower cowl section. Then duct air down from there to blow on the center of the turbo. The HVAC pulls air from between the two cowl halves, so you might get some engine smells unless you figure out filter of some sort. Best thing about this idea is that it looks stock on the outside.

OEMs have beat you to it. NACA ducts on the EVO X and new Type R serve this very purpose. They're actually present to cool the turbo.

 

[PunkST]

OEMs have beat you to it. NACA ducts on the EVO X and new Type R serve this very purpose. They're actually present to cool the turbo.

Thats where i was drawing inspiration from actually 🙂. If it works well enough on those cars. I cant see why it wouldnt on ours.

 

[TyphoonFiST]

Been saying this all along...NACA Ducts! I even put one on my Typhoon for a my CAI that has a box surrounding the Filter. It was genius! Doesn't allow Hot air from the engine in. But only incoming cold air through the duct.

 

[M-Sport fan]

I remember this pic/article in Racecar Engineering.

 

[Intuit]

1) Park near any trees lately? Car STANK when you run that A/C? Clogged drains will eventually result with full removal of the cowling. I actually went to the hardware and installed metal screening just beneath the cowling in a prior vehicle; as I got tired of having to pull it up and use a vacuum cleaner every spring/fall. Then there's the rumor that a large Cicada brood is to emerge this year.

2) Re heat, they intentionally run the engine hotter; for emissions and probably to help keep the cylinders clean. If one wants it to run cooler, can probably just replace the thermostat and/or radiator. But I can say from prior experience, this is also a bad idea. The higher hydro-carbon output eventually (took years) clogged my catalytic converter.

 

[PunkST]

A properly built duct will negate needing to clean the cowling out unless you park under trees all the time. In which case... Try not to park under trees??
Im not in need of a larger radiator. Dont want to change thermostat as i live where half the year you can die of exposure. I have a spare lower cowl section left over from a 2j intake. If i can get the oil temps to stay more consistent when up to temp with no other changes to the car by blowing air across the center section of the turbo. Wouldnt that be a win? Esp. For the folk running much larger than stock turbos and way more heat in that area?