here's a very nice write up on the hellcat box
Prop's to this person for testing
taken from another website (not allowed to say I guess- dumb)
Hello all, let me first say this post will be long and detailed, just so it's clear as to what took place.
I did 4 different acceleration tests and they were:
30-100 starting in 3rd gear
50-140 starting in 3rd gear
40-120 in 5th gear
60-100 in 8th gear
I did 3-4 runs in each test. I had put 265 miles on the AFE Intake when I started the runs and it had 310 on it when I did the last run. The 265 miles originally were put on in mixed city and highway driving, everything from cruising, stop and go traffic, to WOT blasts in low triple digit speeds. So I gave it plenty of mixed adaptation miles.
I filled up the tank both times with the same 93 Octane from the same gas station hours before the testing.
I have a dedicated road that is basically deserted, with no homes, no buildings and no side streets on either side of the road. Large grass median in between and grassy woods on each side of the road.
I start the tests in the exact same spot each time, crossing this black sealant strip line on the road and then I go full throttle.
I would not do the runs if there was any other cars in the area, I would pull onto the shoulder and wait for that occasional car to pass, no matter which direction they were traveling in.
Elevation of street is 10 feet above sea level.
Outside air conditions were:
Stock runs:
79-80 degrees
77-78% humidity
29.95 Barometric Pressure
Gives a DA of 1597 feet
AFE Intake runs:
81-82 degress
80% humidity
29.98 Barometric Pressure
Gives a DA of 1725
As you can see the temps and conditions were almost identical. I couldn't wait for the temps on the AFE to drop any further as it was already midnight, and the low last night was forecast to be 78 degrees at 5 am. The stock runs were done at 11 pm and it was 80 then and dropped to 79 midway through the testing. So that 2 degrees difference was minor but I'd of needed to wait till 5 am to match the temps, but usually humidity is highest in the morning so that would of cancelled out the 2 degree temp drop if humidity went up 5-6%
I was monitoring and recording Oil Temps, Coolant Temps, Intercooler Temps, and the all important Intake Air Temps for each run. Keeping them all about the same, but occasionally if they were different I did a run to see how it affected the times. I learned that anything from 120-140 IAT's seemed to matter none. On one run after idling for an extended period of time the IAT reached 154 degrees and the oil temp was 210 when I pulled out to go and it still matched the prior run when the IAT was at 134 and oil temp at 190.
However on another run when the IAT was at 147 and the oil at 217, it was one tenth slower from 40-120 than it was when IAT was at 133 and oil at 210.
So as stated before, the times on this car are amazingly consistent no matter what the temps are at. As long as you drive it a bit prior to the run, the engine normalizes the temps and all is good.
If you sit there idling for 10 minutes there is no air going in and around the engine and it does warm up a tiny bit, but even then it seems to have little effect on the times. So the car is amazingly good at keeping "cool" or at keeping to a temp that doesn't have much affect at all on it's performance. That may be different on a race track where you are lapping and going full throttle a lot more for a lot longer duration.
So here's the numbers:
30-100 Stock averaged 6.9 seconds with a best of 6.8
30-100 AFE averaged 6.825 seconds with a best of 6.8
50-140 Stock averaged 11.533 seconds with a best of 11.5
50-140 AFE averaged 11.566 seconds with a best of 11.5
40-120 Stock averaged 13.633 seconds with a best of 13.6
40-120 AFE averaged 13.566 seconds with a best of 13.5
60-100 Stock averaged 20.7 seconds with a best of 20.5
60-100 AFE averaged 20.56 seconds with a best of 20.4
So as you can see the only test that had a notable improvement was the 60-100 speed time in 8th gear.
This is of course the most irrelevant of the tests and nobody ever will do a test like that in real life. I did it because I wanted to do a "top gear" test and lug the engine in a big way to see what the results would be. It seemed the AFE was able to help the engine along best in that test.
I know one could say, "wouldn't the times be a bit better if the AFE tests had the same DA as the stock?" Well, first, 128 feet difference in DA is almost nothing, maybe .03 seconds difference, however, I went to my testing location in the middle of the day the other day too, when it was 88 degrees outside and I had only 165 miles on the AFE Intake. I did one of the runs for fun, the 30-100 starting in 3rd gear test, to see what it would do at that point. I got a 6.8 second run. It was the exact same time I got on the stock intake's best time, which I was excited to see that the AFE was able to match the stock intakes time when it was 10 degrees hotter with a DA of 1935 feet (338 feet higher). But it ended up also being the best time I could get on the AFE intake last night too even with a DA of 210 feet lower than that. So again the Hellcat seems to be really consistent even when temps and conditions vary by 10 degrees and 300-350 feet difference in DA. So the 128 feet difference in DA from the AFE runs and the stock runs doubtful it would make any difference at all.
My thoughts: I'm a bit disappointed. I was hoping for a .1-.2 second improvement in every test to show that the intake actually opened up some power for this car when on the road.
As it stands, it did .14 seconds better on average in 1 test, but the one with the least meaning for me and everyone else.
It did minuscule amounts better on average in 2 of the tests, and actually a minuscule worse on average in one test (though that test also had the AFE matching the stock intakes best time).
One one test it did an acceptable job of improving the time but again it was a 8th gear WOT pull that you'd never do on the street or on a track.
The AFE did have one test 40-120 where it's best time was .1 second faster than the stock intakes best time, but it wasn't consistent as the other runs equalled the stock intakes time.
The test that is probably most meaningful is the 50-140 test. It's the biggest speed spread, covering 90 mph in the lowest gear, and it's the one test the AFE did the worse than the stock intake on average, and only matched the stock intakes best time.
So to me, the AFE is doing very little in the power adding department, sadly the same results DAK found out on the dyno. I truly felt the intake would shine on the road tests compared to the dyno, but it didn't. This engine is amazingly capable and consistent no matter if it's on a dyno with limited fans or out on an open road. I don't think I've ever had a car that has such consistency in all areas like this.
Sorry so long, but needed to be detailed.
I have a feeling that without other supporting mods, an aftermarket intake on these cars is pointless and unnecessary. With a pulley and tune these aftermarket intakes would probably be more necessary and show gains over just the pulley and tune by themselves.
I have sent the email for a Return Authorization. I will be returning the intake, as I have no plans to add a pulley and tune to my Hellcat.
Thanks for reading this long and detailed post.
Cheers