Worked on the Hellcat airbox install. The reasoning I went with the Hellcat airbox is because I like using OEM parts where I can for best fit and function with real engineering behind them. Upon researching CAI and the Hellcat airbox the airbox looked to be a better choice and cheaper to boot.
Stock airbox
Hellcat airbox
The Hellcat box has a larger volume,a 3.5" dia hole on the front side for ducting and smoother walls with more gentle curves. It uses the same size and shape air filter as SRT,R/T and even V6 cars, with all using the same airbox lid.
With the box removed you can see where all the air enters the stock box through the triangle shaped hole leading to a cavity usually behind the foglight in the bumper cover. This area is completely enclosed except for 3 small holes that are approx 1/2" dia. Since the Pursuit version I have doesn't have fog lights the covers are solid letting in no additional air but not for long.
Here is a shot from the rear looking forward from the airbox perspective. Notice the black plastic piece next to the headlight. That is the radiator ducting piece.
76mm Holesaw later and direct flow from the grille to airbox.
I cleaned up the area and pulled the coolant pressure tank to clean out the grunge in it and allow for more room to work and photograph. Here's another shot without flash showing the back of the grill.
Sorry for the blurry shot, I was up against the garage door, but this is where a foglight normally sits and the area right in front of the cavity where the stock airbox picks up air from.
Once the hole was cut and cleaned I prepped the Hellcat airbox by adding foam piece to prevent rubbing wear, foam weatherstripping to seal the bottom of the airbox to the triangle opening and moved the rubber grommet and washer grommet from the stock airbox for isolated mounting.
To duct air on 2011-2014 Chargers that don't have the same headlight or routing paths as 15-16 Chargers I used an old hard tube from a shop vac. I cut 2 wedge sections out of the side and glued them back together to get a bend in the tube while maintaining the tube diameter. Here is a shot with it in place to show the direct path to the grill.
Here is another shot of the ducting tube with wedge cuts visible as well as the coroplast panel I added next to the side of the airbox to go along with a foam piece at the top of the airbox to prevent any engine compartment air from entering the airbox.
Here is a shot from the cavity behind the foglight. I had to take the picture blind by sticking the camera in the cavity but you can see the black plastic foglight blanking cover with horizontal slashes in the lower left of the pic.
Now with the airbox base installed and sealed at the triangle shaped hole at it's base you can see the limited air intake potential with just 3 small holes and the mesh on the fender liner that allow air into that cavity. Also note the foam at the top of the airbox lip sealing it to the core support.
New K&N panel filter installed.
I went with K&N as I have always had good luck with them in the past, even with MAF cars and I know they flow well. The interesting part of all the Chargers and Challengers using the same airfilter size and shape is that the V6 and R/T cars use 1 paper air filter and the Hellcat( and possibly SRT cars)use a higher flow rated paper filter with stiffening ribs in the center of the filter. Once that was done all there was left to do was button everything up wit the airbox lid.
The total cost to do the airbox install was about $100 since I had some foam,shopvac tube,and coroplast. I only needed to buy the Hellcat airbox base,K&N filter and small weatherstripping for the base inlet seal.
The charger has air inlet temp sensor so I will seal up the 3.5" opening on the Hellcat box and take some temp readings. Then open it and take some more readings. I already ordered left and right foglight bezel covers from Rock auto at $7.50 each to get more air into the base airbox opening so I will test that also once they come in and spring arrives for warmer temps.