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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #1
My current CAI setup is not a store-bought one, nor is it an OE one. It is in fact a combination of both.

I'm sure you're full of questions at that stunning admission, but let's just keep going before I stop for questions, as I'm sure most of your questions will be answered in some form below.

My first attempt at adding a CAI to my 3.5L started with an el-cheapo unit I bought without doing much research beforehand. As it turns out, the material it was made from left it extremely prone to heat-soak and the HP/TQ-sapping KR spikes that go along with it. Details and photos can be found below in the post titled "Not All CAIs Are Created Equal"

My second attempt at running a CAI was in response to the negatives of the first version and was the result of combining elements from the aftermarket version, my original OE intake unit from the the 3.5L, and part of the intake unit from my 2011's 3.6L. Details and photos can be found below in the post titled "Duct Tape Really Does Work"

My and third (and final?) attempt at running a CAI grew out of a desire to rectify the negatives of the version above obviously, and is the result, yet again, of combining elements from the same 3 air intake units mentioned in the 2nd post. Details and photos can be found below in the post titled "Embrace the Heat Soak"


And now I'll answer any questions that were not answered by the other posts...

Q: "Nuke, what the hell man. You've got duct tape holding your CAI together?!?!"
A: Actually, it's Gorilla Tape, not your standard Duct Tape.

Q: "Okay, so it's Gorilla Tape. WTF?!?
A: I needed a way to attach the two pieces and that was the best way to do it given the pieces I had on hand.

Q: "Aren't you worried about it leaking vacuum at that joint?"
A: I was, but I've logged enough miles with it in place and the datalogs indicate there is no vacuum leak in the intake system.

Q: "But the air you're drawing in isn't as cool now as it was when you were drawing it in from behind the fog light."
A: Yes, but the issue of heat-soak with this particular IAT sensor design meant my PCM never knew the real temperature of the incoming air charge until it had gone WOT for several contiguous seconds. Therefore, the colder air wasn't doing me enough good to offset the lost low-end throttle response.

Q: "Nuke, come on man, it looks like it was designed in a trailer park meth lab and built by a hillbilly with an eye-patch."
A: So, it ain't an SRT. It's a 7 year old glorified SE. In my opinion a little duct tape might increase the resale value.

Q: "But Nuke, what about..."
A: NO MORE QUESTIONS!!
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #2 (Edited)
"Not All CAIs Are Created Equal"

This was my first attempt at getting cooler air into the engine. And while it looked good and worked for the most part at getting the cooler air into the engine, it stunk at actually increasing performance.

3.5 with CAI a.jpg

3.5 with CAI b.jpg

3.5 with CAI c.jpg

The problem is with the stainless steel or aluminum or whatever the intake tube is made from. It soaks up the heat and doesn't let it go even when going WOT. So the cooler air I was drawing in was actually working against me since the IAT was telling the PCM that the air was much hotter. My datalogs had more KR spikes than something with a lot of something else!

Conclusion: the design was fine, but the implementation was severely flawed.
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
Joined
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6,180 Posts
Discussion Starter #3 (Edited)
"Duct Tape Really Does Work"

This version came about by combining the OE air intake tube from my 3.5L, part of the air intake tube from my previous Challenger's Pentastar, and the air filter element (plus joints) from the aftermarket CAI:

FrankenCAIv2a.jpg

FrankenCAIv2b.jpg

FrankenCAIv2c.jpg

While this version virtually eliminated the drawbacks of the previous version, it suffered from a noticeable lack in low-end throttle response, not to mention a hesitation of WOT take-off at highway speeds. Nothing in the datalogs could be used to prove what that might be linked to, but I suspect it was due to increased turbulence in the incoming air stream from the according style tubes used along the whole length of the setup. The KR spikes were gone, but losing ANY low-end TQ in a setup that only has 250 ft/lbs to begin with is unacceptable.

Conclusion: almost there, but still lacking...
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
Joined
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6,180 Posts
Discussion Starter #4 (Edited)
"Embrace the Heat Soak"

This is the current setup I have, and it's by far the best performing of the three:

FrankenCAIv3a.jpg

FrankenCAIv3b.jpg

The KR spikes are still absent and I'm able to up my WOT fuel to +5% in ALL THREE RPM RANGES before seeing anything bad. In addition, the low-end throttle response has returned, and there is no more lag when going WOT at highway speeds.

Now, I can already hear the howling from those of you who will say all this is impossible because I'm no longer pulling the coolest air available from behind the fog light. Well, you're wrong. But don't feel bad, I was right there with you. I refused to believe I could run better without pulling from that cool air pool, but the data shows it is true. And it's not so hard to believe if you think about it.

The engine can only make use of the cool air if it knows the temperature of that air. That is not always going to be the case with a MAP (versus MAF) system. In fact, for the majority of the time my engine is operating, the IAT sensor is telling the PCM that the incoming air charge is quite a bit warmer than it actually is (due to the sensor's design leaving it open to heat-soak). The only way to get the IAT to read the correct temperature is to go WOT for several seconds.

But since I spend more time at non-WOT than I do WOT, I figured pulling air filter element back up into the engine compartment somewhat would benefit the performance from that heat-soak point of view. Sure, the air charge wouldn't be as cool, and therefore as dense, but it would be closer to what the IAT was reading more of the time. Which means less KR spikes from the incorrectly mixed a/f charge, and less KR means more power.

Conclusion: it may look like crap, but it runs good (relatively speaking of course), much better than stock and the previous two incarnations. So for now, I'm sticking with it!
 

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Super Moderator
2016 SXT Plus Blacktop
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17,003 Posts
You had me at "duct tape" ;) Very inventive Nuke!

A Guy
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #6
You had me at "duct tape" ;) Very inventive Nuke!

A Guy
I'm here to tell ya, if you got a problem, and it can't be solved with a roll of Xtra Wide Gorilla Tape (3"!), then that's a problem that dont need to be solved!!
 

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Super Moderator
2016 SXT Plus Blacktop
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17,003 Posts
Amen...

7214525854_733237dd83_z.jpg

A Guy
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
Joined
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6,180 Posts
Discussion Starter #9
Here's another automotive use of duct tape.
While duct taping a turd car with two morons inside it to the bottom of a washer/dryer set is technically an automotive application for the tape, I have no intention of ever buying a washer/dryer set that runs on turd cars and/or morons, so I'm not sure how useful that example is?
 
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