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Discussion Starter #1
What are people doing with their Challenger HellCats after they remove the head light cap on the passenger side?
Are you just leaving it open to cool the windshield solvent?
Or have you plumbed it to send cool air to the air filter/box?
 

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Ive opened them up on all of mine and added D.I.P.S. screens to both sides on now 3 challengers. Just doing that on cars without heat extractor vents will knock down under hood temps considerably. That is reason for doing so on the passenger side. Direct air into the engine bay will help evacuate hot air by pushing it out the bottom as the car moves, as well as helps syphon the air layer flowing over/into the hood scoop(s) into this flow as well. The benefit of an open passenger side port is slightly less on cars that have the 2015 to 2018 hellcat hood, (and more encompassing under belly pans) that hood has heat extractor vents beside but just aft of the center scoop. I did my hellcat anyway, so that they match and given the amount of heat these cars/engines produce, more cool airflow is never a bad thing.
 

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Discussion Starter #4
Makes you wonder why people change there HellCat hoods or why did Dodge change them on the 2019 cars if heat is/was such an issue under the hood.
 

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The new dual scoop (Raisin Bran) Hellcat hood feeds cold air to the engine. The old hood with air extractors did not


A Guy
 

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Makes you wonder why people change there HellCat hoods or why did Dodge change them on the 2019 cars if heat is/was such an issue under the hood.
I cannot claim to know why people change, or would want to change out their OE hellcat hoods, for another style (??),
if there is anyone who has actually done that? (please show us some examples)... its normally the opposite - people adding hellcat hoods & look alike hoods, to non-hellcat cars. :rolleyes:

Ever walk up to a hellcat after its been driven hard or on a hot day??
There is an insane amount of heat bleeding out of the two hood extractor vents. In fact, it will noticably warm my 3 car garage if I close the garage door after pulling in. This same hood design was used on Dodge vipers before the hellcat was ever in production. Its purpose ( in simplified terms) is to do two things -
1. bring cool air in from a fwd raised position in the hoods center boundry layer and ALSO
2. bleed hot air out and push it off to the base of the a-pillars, by way of two depressed leading edge airfoil shape vents, which produces evacuation lift at speed.
Lets assume there is a very good reason why Dodge and many other High perf car manfs, race cars, etc, want to extract hot under hood air/reduce underhood temps.

The new 2019 hood was about increased air flow into the intake system to achieve a HP bump. Dodge basically took the demon hood design and layed flat a channel in the middle, forming two scoops. This was done soley to gain back some of the areo drag penalty caused by the Demons 42 sq. in. scoop, which as it has it, reduced under hood temps by some 30 deg. (again, due to increased airflow) Dodge has already made public statements pretty much to that fact.

Dodge (for the sake of this discussion) does what they do however, out a median consumer/product manufacturing cost/design parameter need basis, gauged for simplified mass production over multiple years & potential cross platform utility.
This in now way makes any system that moves into final vehicle production, ideal for everyone or every driving situation. It also does not negate possible or potential improvement. Otherwise, we'd all drive bone stock cars with no deviation other than paint color, having no need to make anything "better".
Bottom line is underhood heat can be an issue for a variety of ways. The less air there is under there and perhaps more importantly, the less air flowing on, over, under, at & around an engine clamped down inside a metal container (ie: oven), the less efficient that engine is. Hemis are particularly prone to heat soak and temp related timing retardation.
The more air, The better...even if its opening a simple 2.5" hole in the passenger side headlight. (y)
 

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I love the look of my 2019 Hellcat Hood. I know the air flow is better for induction.(10 more HP) because of the hood. But I do believe the old style was probably better for engine cool down. Either here or on Hellcat.org someone posted a pic of the passenger side vent and it didn’t look like it did much. I liked my 2017 Hellcat hood but when they started to put them on Scatpacks it kind of pissed me off. They should have made something new for the Scatpack.
 

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On my R/T, I have the lower Hellcat box and tube on the driver's side. I bought a cap that fits into the back of the "tube" on the passenger's side light and removed the center cap. When I park my car for the winter I remove the cap and run the wires from my trickle charger through the opening to the "charging terminals" under the hood I will reinstall the cap on the back side of the headlight.
 

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Discussion Starter #10
Great input people, I too like my 2016 Cat hood the best, and I have noticed the heat coming out of the vents which makes me believe that the hood works.
I get that the 2019/2020 hood rams in more air to the intake, so does that mean the 2015-2018 Cats under hood temps are less than the 2019 and up temps.
Ten more HP, can you really tell the difference?
And yes I too hate that Dodge put the HellCat hood on other cars, that hood was part of the cool factor in buying the HellCat.

DSCN0351.JPG
 

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Although I can't remember where I read it now, I think one reason the 2018 Hellcat hood was used on the ScatPack, particularly the widebody, is that it extracts heat well, and its design relieves air pressure on the front end to help keep the front end down and maintain control at higher speeds, which was a goal for the widebody to improve handling. Certainly, the negative pressure created by the rear-facing design pulls hot air from the engine bay. Even passively it vents a lot of heat. I am amazed how much I see coming out while idling at a stop light.

I do wonder about the differences between air pressure and air temps for operation of a CAI. The stock airbox ran about 10 degrees plus over ambient and it heat-soaked easily in regular driving. With the hellcat lower airbox mod, it runs about 5 over and heat declines faster after idling or low speed driving. I've seen it run as low as 2 degrees over ambient at highway speeds. So that temperature difference likely translates into some gain, given that is all that is needed to get 10 hp out of the standard Hellcat. (That cracks me up, there is nothing standard about a Hellcat!). But, for a 392 it is likely less than 10hp. Does the extra pressure from the ram air also help? Which is more significant? Temperature or pressure? The reason is, if one had a hood-sealed CAI like the JLT or even the older 6.4 SRT Mopar CAI, would the hood venting be a problem (except for driving on a rainy day)? It seems with the positive pressure from the headlight ram and the negative from the hood vent, it would be moving a lot of cool air over the whole unit, and benefit from closer to ambient temps and rapid cooling. But one would lose the advantage of the higher pressure or mild ram effect. With the other vent open, and with the passenger ram open, there would still be considerable cool air brought in to the engine bay and pressure relief for good handling. I wonder how this airflow looks in a wind tunnel.

Sorry for rambling...
 

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What are people doing with their Challenger HellCats after they remove the head light cap on the passenger side?
Are you just leaving it open to cool the windshield solvent?
Or have you plumbed it to send cool air to the air filter/box?
I have a Scat Pack, but did install the HellCat air box. So I wanted both sides the same so I removed the passenger side cap and installed a rubber 90-degree elbow. It just blows air down into the engine bay but both sides look the same from the front. I couldn't care less if I get more cold air to the engine I just wanted the functional air scoop and both sides matching.
 

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I get that the 2019/2020 HC dual scoop hood does a great job getting fresh cold air in, but why didn't Dodge also add extraction vents on the hood also? You'd get cold air coming in from the scoops and hot air released via the extraction vents: win-win.
 

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I get that the 2019/2020 HC dual scoop hood does a great job getting fresh cold air in, but why didn't Dodge also add extraction vents on the hood also? You'd get cold air coming in from the scoops and hot air released via the extraction vents: win-win.
The dual scoops get air into the engine intake, but extractors behind them would accomplish that and look pretty cool. There is a hundred ways to that hood. Maybe they will one day.
 

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I get that the 2019/2020 HC dual scoop hood does a great job getting fresh cold air in, but why didn't Dodge also add extraction vents on the hood also? You'd get cold air coming in from the scoops and hot air released via the extraction vents: win-win.
it would have looked really busy for one

take a look at the 2020 Toyota Supra - too many styling elements going on without much real estate the spread it over. Then again, that could be applied to many vehicles in Toyota and Lexus lines - a once stodgy company has gone off the deep end with the styling

Restraint in styling has its advantages
 
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