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Discussion Starter #1
Well I'm going to have to test and find out. Interested if anyone else did any before or after"Air Charge mg/charge" readings thru data logging.


You would think if it can feed 707 hp hemi that it would not be a restriction for a supercharged v6.

Sent a 1/4 mile run to Jay from Sprintex, says I have an intake restriction killing about 12% of air flow by 6800 rpms.


Well I looked at the data log, sure enough, I didn't see it, but yes I'm loosing air flow.

So right around 5000 rpm I have around 1480 mg/charge

At 6800 I have around 1324 mg/charge

Drops off the hardest past 5900 rpms.


So I'm going to pull the hellcat box and filter and put my custom fender pull in and filter to see if the numbers come up. If the numbers don't change then it is something past the box possible "elbow" to the tb or it can be the supercharger itself causing the lose.


I'll post my results when I'm finished.
 

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Discussion Starter #2
Little update.

Since this is a supercharged 3.6 v6 I thought I should rule out any belt slippage on the blower, so I did install a smaller belt, tighter fitting.

I also only swapped out air filters.

I removed the factory Hellcat filter and installed a K&N drop in filter.

Bottom line I have more airflow into the engine via the K&N filter. So at least in my testing the K&N filter flows more than the hellcat filter.

So here are the numbers

Hellcat air filter:
6800 1324 mg/charge
6500 1334
6200 1380
5900 1403
5600 1406
5300 1426
5000 1480

K&N drop in filter:
6800 1333 mg/charge
6500 1361
6200 1392
5900 1417
5600 1440
5300 1449
5000 1505

The engine is getting more air, but changing filters did not resolve the PERCENTAGE drop, so I must dig deeper. I'm wondering if it could be the v6 upper air filter lid, the hellcat units have a much better design lid with larger outlet to throttle body.
 

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2015 Dodge Challenger R/T Scat Pack
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It makes sense the K&N filter flows more as they filter less. You did pick up some airflow, but it's less than 1%. I still think a stock Hellcat paper filter is the best all around for our cars. They filter great and provide excellent airflow. The K&N will let in more crap, but it won't destroy anything either, talking negligible amounts. Either one will be fine in the long run.

To my knowledge the fastest Hellcats are running the stock airbox setup. Several guys tried different aftermarket setups only to find they did nothing for performance. A buddy of mine bought an LMI fender pull intake and he said it did absolutely nothing over his stock airbox except make more noise. He calls is the LMI Noisemaker. He put the stock airbox setup back on.

But your car is different, it is not a Hellcat, it is a supercharged V6, so you have a much different setup. It will be interesting to see what you find as to where that restriction is coming from. Keep us posted!
 

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Discussion Starter #4
Another update, so I ported the upper air box lid to smooth it out similar to the hellcat lid, well for right now that looks to have been a mistake, my air charge numbers dropped.

I would have liked have done a back to back comparison once again to confirm it wasn't weather related, but I had only the one lid, so I'm in search of another factory lid.

I also went ahead and did a back to back comparison with my custom cai fender pull and that came up short. the air was cooler sooner to the engine but it was only marginal, I think the restriction in my custom cai is that it was made out of 3" pipe which is smaller than the stock cai lid. The custom cai I built gave me the best mph and e.t naturally aspirated but proves to be a restriction now with the supercharger since the air demand is much greater almost double. It would probably need to be made out of 4" tubing

So right now it looks like from my testing the best combo will be the hellcat lower box, K&N drop in filter with a stock lid, this provided me with best 0-60 times and highest air charge numbers. I will get a new lid and confirm ported lid to stock lid in an A to B comparison.
 

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I think the LMI fenderpull uses a 4" tube. From what I read that was a big deal as most were only 3". You had to cut away some metal in that area to fit that big tube down there. Makes sense.

Have you tried pulling your air filter completely for passes at the track? I always do that. It seemed to make a difference when I first tried it, so I've been doing it ever since. I drive there and back with it in of course, but pull it out for passes. Zero restriction then.
 

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Discussion Starter #6
I went ahead and bought the hellcat upper lid, maybe by chance the lid was designed a little better for air flow and I'm going to try some testing between what I ported and the larger hellcat lid, I know I will have to make some adjustments to make it work since the upper hellcat lid has a larger outlet, try and keep everything as smooth as possible with any transitions, maybe I will just build a new "elbow" to the throttle body, one way or another I will find the right combo of parts for the best airflow thru the data logging. I may try the 80mm throttle body last, I'm thinking the drop in air flow numbers really come from the supercharger, it's a smaller unit that just probably can't move all that air in the upper rpm range, I may have to try short shifting see see if that brings down my e.t. and raises trap speed mph

The no filter thing I have thought about but I may only do that once as a hail marry at the track if i'm really trying to get that extra .10 or so, it's not something I want to do on a regular basis.
 

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Discussion Starter #7
I got the hellcat upper lid, that outlet is huge, it has a 4 1/2" outlet on the hellcat upper air box lid.

I wanted to post the diameter of 4 1/2" outlet just in case some one else is looking for that outlet size, I looked for several hours to try and find the outlet size so I could order parts, didn't find it anywhere one place did say 3 1/2 and 4 1/2 but that person wasn't clear or sure of the size so I went ahead and ordered parts for a 4" outlet...................oppps! I got my upper lid and it was 4 1/2"

So I had to order a reducer from 4 1/2" to 4" since I was building my tubing from the air box to the throttle body out of 4" plastic tubing.

Formula say's 25% larger tubing than the throttle body, my throttle body is 3 1/4" and I went ahead and made it simple by adding 25% to get 4" tubing, so that is big enough to feed the throttle body.

So the hellcat air box outlet is 4 1/2" that will reduce down to my 4" plastic pipe and that will reduce right down to 3 1/4" at the throttle body. I like to think the air will pick up some ram effect by reducing it down a little as it goes.

Before this change it was 3 1/2" to 4" down to 3 1/4", the v6 upper lid has the tiny 3 1/2" outlet and then the air dumps into a large 4" area, I would think that would have some negative effect on airflow as minor as it might be any improvement is better than no improvement.

No way there is any air restriction to the throttle body now. I will do some testing and post results.

Next step will be a larger throttle body to an 80 mm and see if there is any change in air charge numbers. If anything it will give me more power at launch since the program does not allow full throttle til 4900 rpm, a larger throttle body opened at same percent has more airflow, so I should have more power for launch.
 
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