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The Hellcat headlight intake sucks

26K views 71 replies 34 participants last post by  mikeychallenger 
#1 · (Edited)
Just installed the Hellcat headlight intake setup. Can't believe how much it ... sucks!

This was with my girlfriend revving it (which she was afraid to do) she said it only got up to 3000 maybe 3500 rpms.

...trying to post the video. Looks like I'll have to put it on YouTube first.

Here it is:
http://youtu.be/uhBYW74PgAs


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#4 · (Edited)
Just installed the hellcats headlight intake setup. Can't believe how much it sucks!

This was with my girlfriend revving it (which she was afraid to do) she said it only got up to 3000 maybe 3500 rpms.

Here it is:
http://youtu.be/uhBYW74PgAs
Really sucks in oustide air w/ throttle & add the ram air effect once you're moving!! DAMN!!! So glad I did this & opened the brake cooling duct in the lower compartment for even MORE fresh air!!

Woz.. THANKS!


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Oh WOW!!! So glad I did this mod!!!!
 
#8 ·
once i do this mod i make sure i tell my kids stay out of the front if you dont wanna be eaten...lol..good one
 
#10 ·
Haha. Awesome.

And I don't know if my driving is better or if the intake had anything to do with it but I was able to get a 4.3 second 0-60 today vs. my previous best runs of 4.4 seconds. I could very consistently get 4.4 before, and then today I tried 5 times and got 4.4, 4.3, 4.3, 4.5, 4.4.

I'll never know if the intake had anything to do with it but oh well!


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#12 ·
Went driving around town for about 30 minutes last night. Lots of stoplight sitting, some fun launches from lights and some cruising in the 30-40 mph range. Ambient temperature was 43 degrees. The intake temp seemed to want to stay right at 51 degrees. It would get up to 65-70 when sitting at a light and drop back down to 50-55 within a couple hundred feet under light acceleration. Under heavy acceleration the temps would drop down into the high 40's.

Unfortunately I've never really monitored the temps this much before around town. I have on the highway cruising at high speeds and with this cool weather it would always be within 5 degrees of ambient. I'm interested in seeing what it does tomorrow on the way to work.


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#17 · (Edited)
Ambient temperature was 43 degrees.
<snip>
Under heavy acceleration the temps would drop down into the high 40's.
Sounds like your IAT reads about 6 degrees high at that temp, like mine. You have to "calibrate" your IAT by looking at the difference between outside and IAT when you first start the car. I bet when you first start it, your outside temp is showing 43 and your IAT is showing 49. Drive off before the car can warm up and while driving, monitor it for like 1 mile to see if the IAT is staying +6 off. If so, that's your "calibration": you'll need to subtract 6 degrees from what the IAT is showing to give you the actual IAT (or at least one that is comparable to the outside temp reading).

Keep in mind that I've done a lot of IAT monitoring and it's not always off by the same amount. Mine is off about 6 degrees when it's 50 outside but only 3 degrees when it's 80. So basically, each time you monitor it, you need to take note of the IAT-versus-outside delta and go from there. I read many of you saying "mine reads 9-12 degrees above ambient at speed". That may not be true. You really have to "calibrate one to the other". You may actually be running right at ambient, even with the stock box!

Another tip: even if you soak it to 70 at a light, it will drop very quickly when you start moving (as you noted), but it will still be 3-5 degrees above ambient until you bleed off that last ounce of heat soak. That takes maybe a mile (with the hellcat box and brake duct mod... about 4-5 miles stock). After running it at speed for a mile or two, it'll settle at some temperature (let's say 49). At that point, mash the throttle at least halfway for 3-5 seconds. If it does not drop during that short acceleration burst (stays at 49) while the throttle is mashed, you'll know it's actually at ambient temperature. Typically when it goes down a few degrees when the throttle plate opens, there's still a tiny amount of heat still sitting in the system. And it bleeds off within a few seconds if you open the throttle plate and get good flow going.

Mike
 
#14 ·
With my luck I'd clip a bird through that vent going 70 mph. Birds have been known to take down jet airplanes on takeoff. I wonder what they can do to a car lol?:surprise:
 
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#18 ·
Yeah, the sensor could be off I suppose.


Or could it be off at start-up because the sensor is in an "insulated" area. Under the hood, inside of a rubber tube.


Just like why my insulated unheated garage is always warmer inside than out in the cold weather. As it gets warmer out though the differential is less and less...


Just a thought !


And for the brake duct I think I'm going to buy an extra duct piece and cut a hole in the top of it and epoxy a plastic duct piece to it pointing straight up towards the "rabbit hole" opening.
 
#21 ·
Yeah, when you first start up though after it sits overnight, everything should have equalized in temperature, so that's a good time to check it. Used to be, you'd have to drive over some speed (say 35 MPH) for a certain length of time for the outside temp to update. But at least on the 2015's, the temperatures update as soon as you start the car so that's a good time to check the differential between the readings.

I'm thinking about your idea to drill the duct. If you go that route, I think whatever piece you use to direct air upward should probably stick down into the duct a little. For people just drilling some holes in the duct, nearly all the air might tend to stay in the duct because there is very little restriction from that point out into the wheel well and with nothing sticking out into the stream of flowing air, not much may "leak out" through those side-holes.

One thing I thought of that you might consider. Imagine looking down onto the duct: in place as if everything were stock. What if you were to cut a little "flap" in the top of the duct and just push down and crease it so that the flap pushes down on the leading edge? I've attached a sort of "ignorantly crude" mock-up of what I'm talking about. Air coming in through the front would hit the flap and some of it would be forced up and out, right under the air box. You could cut that flap wider/narrower to taste: obviously the further down you push the flap into the airflow stream and the wider you make that flap, the more air comes up and out.

Mike
 

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#19 · (Edited)
:cowtounge:
Just installed the Hellcat headlight intake setup. Can't believe how much it ... sucks!

This was with my girlfriend revving it (which she was afraid to do) she said it only got up to 3000 maybe 3500 rpms.

...trying to post the video. Looks like I'll have to put it on YouTube first.

Here it is:
http://youtu.be/uhBYW74PgAs


Sent from AutoGuide.com Free App
Is it the low beam headlight that has to come out to do this mod. Will this work on my 2012 SRT challenger?.
 
#20 ·
It's just a cap in the center of the inner headlight that is removable. It is only on the 2015 models. You don't need to remove the headlight to do this.
 
#22 ·
Not a bad idea.


I'm thinking of attaching a duct piece that sticks up towards the "rabbit hole" maybe come within a couple inches of it. Ideally I think it would be awesome to have an actual duct piece that was made to connect the two. My thought is that when you punch the throttle and it has that large suction (the same suction that almost sucked that tissue through in my video) it will suck cool air out of the brake duct. While not under throttle it will still flow area to the brakes as usual.
 
#23 ·
Elbowing or deflecting the duct is not needed.. As long as outside air is in the lower compartment, it will get pulled up thru the filter.

Again, what I did in order to prevent the incoming air from going out thru the opening in the wheel well, was cut the back half of the duct & seal it with duct tape & re-insert it.

Now all incoming fresh air stays in the lower compartment with none going out thru the wheel well..
 
#33 ·
Great demonstration so bad@ss!
 
#34 ·
I gotta stop coming to this forum...every time I scan the threads I find another reason to spend money. I'm trying to buy a house fellas!

Awesome demo by the way!
 
#40 ·
Now, using this hellcat box, can a cai be added? Is there one out that will fit in the stock box with the top off? Or is the concensus now that we are better off with the stock (hellcat) air box and filter? Would be nice to fit a good conical filter in there.
 
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