Tuft test on 2021 Wrangler hood vent

[@JoelDevich]

I found the same thing when I cut mine. My temps went up. I covered them back up with the underhood pad. So it does let more hot air out but still blocks the flow back down

[@betweenthepines4000]

I worked for FCA years ago, left in 2017. I had a few people who loved the ram 1500 sport and the sport hood. They would always ask why the hood scoops weren’t functional and dumb it was. No, its actually smart. At speed those hood scoops would actually create positive pressure in the engine bay and not allow front end air to pass through the front end as easily, thus compromising cooling during heated operation. Although different as these dont scoop, they cowl, but almost creating the same affect as you can see here. Very not scientific but you get the idea. As for slow operation, yes they could help in say Moab or other low speed engine operation.

[@overlanding21]

And that was my main reason behind wanting to do it was for low speeds. This was to show what opening the vents would do at higher speeds. We had this done half a year ago and our engine Temps aren't noticeable different on the highway in winter or summer driving.

[@gawdzinner1561]

I don't think the air is getting "sucked in" at highway speed, rather, the air is getting "pushed in" by the higher pressure on the outside of the hood versus the pressure under the hood.

[@mallkrawlerz620]

vents aren’t meant to make an engine run cooler. the engine is set to run at a specified temp for many reasons including emissions and even something as simple as… those are your engines normal idle or running temp parameters. But The vents are more to dissipate heat at low speeds which helps avoid future damage or damage from heat long term on other components that aren’t meant to run as hot as the surrounding areas. With that’s said, that process seems to work best at low speeds because at higher speeds pressure changes can occur and vortex patterns can occur as seen by your video, thwarting the hoped for, upward air movement. They’re def not for esthetics when understanding what’s they’re job really is.

[@cirquedumike]

Its more for reducing heat pressure in the bay overall and any more excessive overheating when driving hard

[@richardmoore2003]

Thought...wonder what would happen if you put a clear cover over the top front of the vents. Kind of like what goes over a roof top RV vent. Then you would remove the highway speed turbulence from the test and isolate the yarn to see if any air flow is coming from under roof.

[@overlanding21]

not sure, but i wouldnt want to add more covers to my hood, I did my vents like that for the low speeds when I offroad. Made the video for a viewer that was on the fence of doing the hood vent mod to see how well the air flowed at highway speed. While off road i do see heat coming out of the vents so to me it at least gives me that warm and fuzz feeling that it is helping.

[@junkemails5050]

Iam not even looking for dontht on a jeep, but on a mk4 tdi 1.9 jetta, i just wanted to run the intake lil cooler, the problem i Have is intake temp at 100 plus on sunny says around 60f and 78 on around 35f

[@overlanding21]

Take the rubber seal off on the front and back of the hood, it will let more air in and out. Did it on my mazdaspeed3. Good luck

[@junkemails5050]

Damn man i loved the idea, didn’t think about it. I will do it, not sure if would get water on rain or at least heavy rain, but i can always put back on.

[@casper-photonvideo]

Was this just an air test to see if there's any flow in or out?? or did you actually open them up trying to create a little more ventilation?? There are a couple companies now that make vent replacements that will make them into functioning vents.

[@overlanding21]

They were opened up in a previous video, a viewer requested the tuft test to be done to see how the air flow would be at higher speeds. I did it to help air flow at trail speeds.

[@lanckie]

So, opening the vents is not for driving... it is when you are wheeling it let's the hot air out of the engine bay to keep engine cooler. I opened mine and the jet of a fan hardly ever comes on now and I wheel pretty hard sometimes

[@endeavourco]

"jet of fan" do you mean jet of air? lol

[@overlanding21]

Yes, I opened mine up for when I go offroad. When i was in California my engine fans used to kick into high do the the engine heat getting very high. This was in hopes to mitigate that, with the JK i ended up taking the rubber seal off the back of the hood to allow more air to exit from under the hood. But with the vent opened i did not expect that air would be getting sucked into the engine bay. I would have expect some air to be escaping through the vents out of the engine bay and not the other way around.

[@lanckie]

@@endeavourco no, the JL radiator fan literally sounds like a jet getting prepped for takeoff... its horrible when you want the serenity of the woods I wheel in

[@zerodrift1]

First off, thanks for taking the time to document this! And secondly, how about that! I did not think air would be sucked into the engine bay while driving. If anything, I would have guessed it would have been neutral or just a little more turbulent, but certainly not flowing in the opposite direction. Aerodynamics are a really tricky thing to pin down, but there are things you can do to manipulate airflow. At the top of the first vent, if you have a raised lip, it will cause air to flow upwards. This creates a vortex of lower pressure behind, which should encourage airflow to exit. Here is an example of a race car in a wind tunnel: kzbin.info/www/bejne/f3KkepR5m7yDj7c Notice the first vent is nearly vertical. That is what catches and trips the air behind it. Now that I've my Gladiator, I'll be trying this out soon and will let you know if I can get any improvements. I will say that this will certainly help with low speed crawling as the hot air will rise and be drawn out more easily. At freeway speeds, it may actually have a negative impact on the cooling capacity of the radiator, though that would be very difficult to test/prove. Again, awesome test! When I get results, I'll share them.

[@overlanding21]

I appreciate the idea, I started watching more videos on aerodynamics to see if my friend that does metal work can make something to replace those plastic vents. Would love to see your results.

[@zerodrift1]

@@overlanding21 sounds good! I'll work on this over the weekend and will see about getting a video posted.

[@salvatorecipolla1441]

Hi Where are you that area is Beautiful

[@overlanding21]

This video was shot in North Carolina. But there are install videos in PA and FL.