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When I ran a vented hood, it really helped the turbo heat escape especially at a stop light. You could definitely roast a marshmallow over the passenger side vent. No data on it though
Edit: Well, yeah, ...just went back and looked at your set-up, forgot you've that huge turbo mounted up top right there. After a couple of runs...grilling marshmallows would definitely be in order.
Nothing like that..., but I've the same after returning from a drive...the vents definitely do a great job venting heat at a stand still. I'll have to do some testing to confirm what's happening at various speeds.
When I ran a vented hood, it really helped the turbo heat escape especially at a stop light. You could definitely roast a marshmallow over the passenger side vent. No data on it though
Noticed this with my vented hood too. Temps were relatively unchanged at cruise but as soon as I hit traffic or stop lights my temps were slower to rise. Prefer the look of my stock hood over the CF of my Seibon vented hood though so reverted back.
Noticed this with my vented hood too. Temps were relatively unchanged at cruise but as soon as I hit traffic or stop lights my temps were slower to rise. Prefer the look of my stock hood over the CF of my Seibon vented hood though so reverted back.
Agreed...I couldn't find a vented hood I liked..., too gaudy for my tastes, much less enough to drop 7 or more Benjamins. That's what prompted me to start looking for alternatives a) that I liked, and b) that weren't so expensive...though I'd have happily paid it, if I liked them.
edit: well I hope you saw that and understood into my previous words, because otherwise it’s a discussion that should be occurring in private and I still only wish the best for you no matter how incorrectly perceived my intent may be
Maybe I should have mentioned we went through all this many years ago to save you from all that typing. Seems like I had mentioned that stuff about the front of the hood 5+ years ago too. Well that’s ok, it’s still a good mod and it should be fine. Too bad there’s not a counter for just telling people you liked their post.
As indicated w/~3 dozen threads on the topic I didn't come across comments by you about dynamics at the front of the hood, but did see your below comment about the back of the hood...
Originally Posted by TeamRX8
Piece of cake and probably less cost compared to the hood vent, it sounds like the fun exercise concept lost its twinkle. It probably would have been just as effective to put spacers between the hood and the rear hinges to raise the back end of it up...
it just depends which direction you want it to go as I posted in the radior blockhead thread, it’s not just about getting hot air out, but cold air in too.
I’ve also posted on here, maybe even in this thread, that nobody has done more stupid stuff in their past than me. Nobody is born knowledgeable or wise, it’s usually gained in time. I still luv and forgive you bro, no matter what.
You're not alone, bro. You can't be outspoken and opinionated w/out ruffling a few feathers...or wishing you had a few backsies in your pocket. Been there and done similar too.
So, yesterday's tests were at end of day... losing daylight...and on wet pavement. So tests were at ~50 mph. But w/ dry pavement today I was able to squeeze in a few higher speed runs to round out the testing.
The indicators definitely show air flow out of the vents at all speeds. So, I'm pleased w/ vent placement. How much that reduces actual temps in mid summer heat?
Additionally, anecdotally...after returning to the house...I'm confident the entire engine bay, e.g. intake & charge sections, and components were definitely cooler than before the vent installation. It was worth the investment.
Excuse my ignorance, but how can you tell from the videos posted that the air is flowing through the vents? To me I cant tell whether its going right over the hood or through the vents. Is it the air space just below the vents? Would the string be flatter to the hood if the air was flowing right over the hood?
Excuse my ignorance, but how can you tell from the videos posted that the air is flowing through the vents? To me I cant tell whether its going right over the hood or through the vents. Is it the air space just below the vents? Would the string be flatter to the hood if the air was flowing right over the hood?
No worries...good question. Air will flow from higher to lower pressure areas. It's physics. It's very unlikely that the air pressure w/in the bay is precisely the same as the air pressure passing over the hood. While possible...improbable.
So, while three results are possible, I expected one of two: into or out, and expected the following indicator responses correlating to the flow direction of air:
air exiting ..............(indicators would "stand-up" / "dance about")
no noticeable air flow (unlikely, but possible) ..............(indicators would lay flat along the hood)
air entering ...............(indicators w/b sucked into the vents, i.e. disappear)
I'm confident that the indicators are standing-up" & "dancing about", which can only be the result of the force of air exiting the vents. You m/b able to see more clearly by intermittently pausing the vids to view "stills" rather than in motion. I also specifically posted vids starting from a stop or low speeds to see the transition.
you didn’t actually try lifting the rear hood though; go ahead and prove me wrong
. I'm good. I conceived my theory based on physics (CFDs), tested, and validated it experientially.
On what is your theory based? The same CFDs indicate PC is greatest at the rear of the hood, suggesting minimal venting; conversely, most likely ingestion of air..., increasing the bay pressure...we're trying to relieve to vacate heat...from the bay, AND increase rad/IC flow to reduce ECT & IAT. ???
Aside from "talking" and attempting to save face... what good do YOU *expect* it to do?. Where is the sense in doubling down on this?
Regardless, if YOU are confident it has value, ...why don't YOU test, and validate YOUR theory has merit?
Excuse my ignorance, but how can you tell from the videos posted that the air is flowing through the vents? To me I cant tell whether its going right over the hood or through the vents. Is it the air space just below the vents? Would the string be flatter to the hood if the air was flowing right over the hood?
I'm kind of on this same page..... Technically the faster moving air over the top of the hood creates a low pressure over the top of the fingers (think airplane wing) which would cause the finger to stand and "dance" regardless. Here's how I think a better way to validate this would be.
Connected the anchored ends of the fingers under the hood below the vents. Attached some fingers to the top of your hood (not on the vents) and see how they react. If you see the finger from under the vents pop out then voila, airflow from inside the engine bay to outside. The fingers on the hood are just more for curiosity and visual reference. I'd imagine them to either move straight back towards the windshield or "dance" due to the high velocity low pressure air flowing over the tops of them.
Last edited by RotaryMachineRx; 04-02-2020 at 12:40 PM.
I'm kind of on this same page..... Technically the faster moving air over the top of the hood creates a low pressure over the top of the fingers (think airplane wing) which would cause the finger to stand and "dance" regardless. Here's how I think a better way to validate this would be.
Connected the anchored ends of the fingers under the hood below the vents. Attached some fingers to the top of your hood (not on the vents) and see how they react. If you see the finger from under the vents pop out then voila, airflow from inside the engine bay to outside. The fingers on the hood are just more for curiosity and visual reference. I'd imagine them to either move straight back towards the windshield or "dance" due to the high velocity low pressure air flowing over the tops of them.
Jesse - Good idea. I agree...a more definitive test. I'll set-up and run that one as well.
Jesse - Good idea. I agree...a more definitive test. I'll set-up and run that one as well.
Giving this a bit more thought...my concern is having the indicators get "caught" under the vents, and giving a false negative. So, best I can think is to tape them kinda sideways as low on the vent fin as possible to avoid this...
I think what w/b ideal is affixing some kind of smoke generator on my undertray just in front of my rad. Then it's a simple matter of seeing if the smoke flows through vents.
03-30-2020, 11:56 AM
I'll have to do some testing to confirm what's happening at various speeds.
