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Installing CAI on brand new car

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7K views 36 replies 16 participants last post by  Michael Plummer 
#1 ·
I just got my 2017 TH with 24 miles on it and i wonder is it OK to install CAI now or should i wait for say a 1000 miles ?


Also what type/brand of CAI you guys recommend ?
 
#2 ·
Congrats on the purchase. I like the new styling and extra options on teh 2017 but I couldnt wait the extra week for one (I should've). I cannot confirm if it would be bad. Personally I would wait as I like the sound it makes and am not gentle on the throttle. I just hit 2000 miles and ordered a spectre intake. It is almost identical to the K&N except it is $130 cheaper. Mine will be going on today. I also put a pedal commander on but am most likely sending that back as it does nothing for me, other than not require me to mash the pedal as hard.
 
#5 ·
If you have a 3.6L, then right now K&N is the only company that has released a 2016-17 intake for the new engine design. 2015 and older intakes wont fit.

The first pic is the 2016-17 intake, next is the 15 and older.
 

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#16 ·
I'm interested in Volant. Does anyone hear/feel/see any difference by adding the CAI? Sound Better, better acceleration, better gas mileage, or nothing at all?
 
#19 ·
Has anyone had their v6 on a dyno that can qualify a performance improvement? I have a new TH and have been going back and forth about installing a CAI. I want the small performance boost more that sound, so if it doesn't add anything but noise I'm not interested.

Thanks all
 
#25 ·
#26 ·
The issue with the 3.6 is that the intake tube is so long and exposed to hot underhood air. For a CAI to do anything useful it needs to be insulated. On a hot summer day a steel or aluminum tube delivers hotter air to the IAT sensorr at cruise than a stock plastic one.


Question is what do you want ? Sound, appearance, or function ? If the latter then you might just order a stock intake "tube" that breathes over the radiator support, and modify to remove all the extra chambers and furnaces. You also get a spare IAT.
 

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#27 · (Edited)
The issue with the 3.6 is that the intake tube is so long and exposed to hot underhood air. For a CAI to do anything useful it needs to be insulated. On a hot summer day a steel or aluminum tube delivers hotter air to the IAT sensorr at cruise than a stock plastic one.
You bring up a valid point, that's where a plastic tube may be more beneficial. But once the vehicle is moving the difference in air temperatures isn't that significant. And at WOT air is moving to fast and isn't really affected by the temperature of the intake tube (aluminum or plastic).

Things of importance:
1) The more air that enters the engine, the more fuel can be burned. This will increase a vehicles maximum power output.

2) IMPORTANT: This will only be of use at WOT and not part throttle.

3) When the throttle is not fully open, the throttle plate is restricting airflow into the engine. No matter how much you decrease airflow resistance before the throttle plate, airflow is still at the mercy of the throttle plate.

4) The throttle plate is there because an engine will pull in more air than it needs at lower RPM. The only time an engine will struggle for air is at WOT and high engine RPM. This is where a little more airflow may be of some benefit.

I hope this helps
Michael Plummer
 
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#29 ·
You can't burn more fuel if the computer doesn't deliver it, timing helps.
The thing I found is the OE intake on a 3.6 even with the silencers/resonators can deliver as much air as the 3.6 could ever use. Volume wise it's more capable than the K&N, and the turbulence created by the small openings is negated. I ran both and "tested" for temps and agree mostly.

What I like is that every engine and every intake are different and that is where the "it works" argument gets lost between party noise maker and more horsepower. I do think that if we made a real cold air intake with a good initial opening the v6 would see gains. But even a cone filter in a box pulling from the stock location isn't going to show past the dynos error rate. Mostly opinion.
 
#30 · (Edited)
Q) You can't burn more fuel if the computer doesn't deliver it, timing helps.
A) If more air enters into the engine, the processor will deliver more fuel(by increasing the pulse width on the injectors) to meet the increase in air flow. Not sure why this is a hard concept to understand.

Q) The thing I found is the OE intake on a 3.6 even with the silencers/resonators can deliver as much air as the 3.6 could ever use.
A) If the OEM is going to cheat somewhere, it's going to be the air intake and the exhaust manifold. The stk. paper air filter is restrictive. The stk. OEM resonator is designed to reduce noise, hence the name resonator. And anything designed to reduce noise will kill air velocity because of the air turbulence in causes with stuff protruding into the air path. The net effect is less velocity and air flow going into the engine. Not sure why people can't understand that?

Q) Volume wise it's more capable than the K&N, and the turbulence created by the small openings is negated.
A) Not correct

Q) I ran both and "tested" for temps and agree mostly.
A) Temperature difference is not the issue here. If I have time this weekend, I'm going to do a video of the temperature difference between the stk. air box and a CAI at cruise and WOT. You'll see how fast the temperature drops when the vehicle starts to move with a CAI among other things.

Thanks
Michael Plummer
 
#32 · (Edited)
Q) If that helps you sleep at night, keep telling yourself that.
A) The four things needed to make an engine run are, Air, Fuel, Spark and Compression. Spark and compression aren't going to change without aftermarket parts. You increase air flow and don't increase fuel then you run lean. The short and long fuel trims will adjust fueling to meet air flow demands and that's a fact. If the vehicle has a Mass Air Meter, the meter will measure (the beauty of Mass Air) the increase in airflow or air mass and the processor will make the necessary changes to fueling to meet the commanded Lambse.


1. Hard to understand? It's not. But how do you know the stock tune would account for any potential gains in airflow? I don't think you know, but of course you could get a custom tune. But you're still at the mercy of the throttle plate as you said, which could be a restriction - do you know?
1A. I do know but I'm not sure if I understand your question. The processor will account for increases and decreases in air flow. Again the processor will adjust fueling and you can see those changes in your short and long fuel trims. If you have a handheld tuner, I know they have those as parameters you can view. I'll be happy to explain in more detail how those fuel trims work. Like I said before, a CAI is beneficial at WOT because the throttle plate is basically taken out of the equation.


2. Have you cut open the resonator - how do you know it's not just an open box?
2A. I've seen inside the 5.7 resonator but not the 3.6. By definition a resonator is designed to reduce noise, that's its main function and not increasing air flow. So if you can remove the obstructions air velocity and air flow will increase.


3. Even if it does slightly reduce air velocity, who says it's reducing it to a point that actually affects the power of the 3.6?
3A. As a rule of thumb, 10 degrees of cooler air inlet temperatures will increase power by 1%. 5 degrees cooler air, power increases by 0.5%. So slightly reducing air velocity will net you lower HP. Is it significant? No. But to verify, you can test your parts on a dyno or at the track to see if increases in HP or TQ were measured or loss.


4. Doesn't matter how fast the temperature drops. Point is, it's going to be sucking in much hotter air than the stock setup whenever the vehicle is sitting for any period of time.
4A. You are correct about sucking in hotter air at idle. But hopefully, everyone is more concerned with performance and air temps when the vehicle is moving and not at rest. I tested this the other day. I let my vehicle idle for 20 mins. Air Inlet Temperatures (AITs) got as high as 91 degrees. Ambient temperature was 39 degrees. As I drove the distance between three telephone poles AITs dropped to 46 degrees that fast. And my vehicle speed was 20-30 mph.


5. "Cold" air intakes are a waste of damn money for a lot of vehicles, these included. The stock paper filter and box that flows the 3.6 and 5.7 is the same box design for the SRT. It is slightly restrctive on the SRT and is a worthwhile upgrade (prior to 2016 - they finally made it bigger on the newer vehicles by the looks of images on Jeep's site).
5A. I agree on smaller 4 cylinder engines a CAI isn't worth the money on the vehicles I tested (Honda, Subaru, Golf and Scion). On vehicles where the stk. OEM intake has less restrictions the HP increases may also be not worth it. But how do you know? Someone, somewhere, has to test it. And hopefully they'll use a dyno to verify if gains were noticed or not.


6. So explain to me how the filter/box that works on the SRT is tragic for the 5.7 and 3.6? It's not.
6A. I'm not sure what the stk. OEM air intake system looks like on the SRT. On the 5.7L and 3.6L engines, I have dyno results from my own vehicle and I have a friend with dyno results on his 3.6L. We both have HP and TQ gains to the tires. The main advantage of a dyno is quantifying the results of a change, hence the reason why I and others use them.

7. And even if an intake does add a few ponies, they're still not worth the money.
7A. If that's how you feel that's cool but that's your opinion. But to blindly say something works or doesn't work when you have no type of data to back up you're saying or information to point to, isn't cool.

8. These are Jeeps. Not high performance vehicles. Who gives a damn if it makes a few more HP, because it really doesn't matter. If you want aggressive sound, or cosmetic looks, then by all means.
8A. I know what Jeeps are, I've had 3 of them already. If I want to spend my money on these so-called performance parts that's my concern and not anyone else's. If I go out and spend my money on dyno testing and quarter mile runs down the drag strip I do it for me. And I also use this public forum to share information to others who may not have those resources available to them.

9. But if anyone buys an intake thinking they are going to have some noticeably positive effect on power or fuel mileage, they're just going to get the placebo effect or disappointment.
9A. I believe I mentioned in one of my posts I couldn't really feel the difference in HP when I went from my custom tune to the stk. tune and that's because it takes more HP to the tires to actually feel a difference in the car. If someone says they can actually feel 10-15HP increases, then they have a better super duper calibrated butt.

Thanks
Michael Plummer
 
#34 ·
Information on how the Jeep's 5.7L Engine Management System (EMS) works is almost non-existent. I did some data logging today and found out a little bit more on how the Jeep's 5.7L EMS works.

Since the stock O2 sensors are narrowband they only work around 14.7:1 and that's it. The processor will calculate the airflow into the engine, based on the following sensors and information: the size of the engine in liters; the intake manifold absolute pressure, as determined by the MAP sensor; engine rpm and AIT sensor. The air temperature is a factor because a change in temperature will cause a change in the density of the air.

The processor learns in closed loop fuel mode. By keeping the engine in this mode, you can cover enough locations in the Volumetric Efficiency (VE) table to get an overall view of your engine's tune. Covering every single location is not needed, nor is it possible as the VE table covers areas the engine will never run in. When you get into WOT this will turn off closed loop fuel mode. Short Fuel trims learned will be copied to the long fuel trim and then applied to WOT.

Thanks
Michael Plummer
 
#37 · (Edited)
Silroc88,
Thanks for the kind words but I don't have all the facts (trust me). My Engine Management experience is on Ford Mustangs (1989 - 2016) with Mass Air, so it's a learning curve for me.

Based on the limited data logging I have done, combined with what little information I have found online, I'm trying to get a better understanding on how the 5.7L engine management strategy works but every time I think I understand, other information pops up and proves me wrong.

Once I can confirm how it works, I'll be sure to post the strategy here in a new thread. It should take the guess work out when someone is trying to understand how the processor deals with so-called performance items.

Thanks
Michael Plummer
 
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