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Discussion Starter #1 (Edited)
For those curious, I did some data logging regarding the air intake temperatures between the stock air intake setup and the C&L Intake setup.

Concern: C&L aluminum and metal tube CAI heats up the air intake temperatures in comparison to carbon fiber or molded (like the stock intake) tubes.

BLUF: Air intake temperatures were generally the same between the stock and the C&L setups.

Ambient Air Highway: 53 deg
Ambient Air City: 56 deg

Stock Intake
50-70mph highway driving
IAT Reading: 62.8-64 deg
10-40mph city driving
IAT Reading: 70-75 deg
Idle
IAT Reading: 75 deg slowly increasing to 80

C&L Intake
50-70mph highway driving
IAT Reading: 63-64 deg
10-40mph city driving
IAT Reading: 71-75 deg
Idle
IAT Reading: 75 deg slowly increasing to 80


Overall, intake temperatures for both applications were 10-15 degrees above ambient during highway driving and 18-24 degrees above ambient in city/idle driving.

So for those concerned with purchasing cold air intakes, the difference between an aluminum intake tube and stock intake tube had little to no change to the air intake temperatures at operating speeds/idle.

Also, it should be noted that I tested the C&L with and without the air box. The main difference in temperatures without the air box was +2 degs in highway and city driving and the at idle temperatures increased more quickly and rose to 90 deg. The bottom line, having separation between the engine and the air filter will help increase the amount of time it takes to heat up the air filter due to hot engine air. Think of it as housing insulation.

From a performance standpoint, I see it as more reasonable to say that your HP gains from aftermarket Cold Air Intakes is not because it pulls in cold air, but rather it increases the amount of air available to the engine and reduces the restriction of air compared to the stock setup.

Hope this helps your decision on Cold Air Intakes and helps eliminate some of the fear factors.
 

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Interesting figures! I hope you consider collecting some more data once the summer months roll in, again. Got to admit, sub-60 deg ambient temps kind of helps the whole situation along on its own. ;) When you are surrounded by nothing but hot air, that's where heat soak really takes a toll, imo.

I would also concentrate on city driving tests (since hwy driving tends to arrest the condition itself out of reliable, constant air flow), beyond 20 min. If you get to sitting still in traffic a few times after that point, there are few sources left for local sources of cooling, and that is when the intake temps rise up considerably. After the 20 min point of vehicle running, you should be into at least the 1st/2nd cycle of the radiator fluid exchange. Once the fan gets to blowing with the radiator at full temp, the hot air soak circus gets cooking inside there.

I'm not suggesting that the temps would really be that different between different intake parts, but I would target those scenarios where heat contamination would really see a heavy stress test.
 

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True, it's all good right now. July/August is a different story.
 

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Thanks for taking the time to test it.
I must admit, the Mopar CAI would heat soak my engine and create a very rich idle in the Summer with temps in the 80's and 90's. It would just dog the engine off the light. The aluminum intake would also stay extremely hot to the touch for quite some time. Even the stock air box performed better in the Summer when idling.
 

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Thanks for the numbers. I was on the fence with the cold air setup since it would be drawing underhood hot air unless it sealed completely to the hood. I think I might stick with the stock box and try to get some flow out of the bottom snorkel. Any ideas?
 

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For those curious, I did some data logging regarding the air intake temperatures between the stock air intake setup and the C&L Intake setup.

Concern: C&L aluminum and metal tube CAI heats up the air intake temperatures in comparison to carbon fiber or molded (like the stock intake) tubes.

BLUF: Air intake temperatures were generally the same between the stock and the C&L setups.

Ambient Air Highway: 53 deg
Ambient Air City: 56 deg

Stock Intake
50-70mph highway driving
IAT Reading: 62.8-64 deg
10-40mph city driving
IAT Reading: 70-75 deg
Idle
IAT Reading: 75 deg slowly increasing to 80

C&L Intake
50-70mph highway driving
IAT Reading: 63-64 deg
10-40mph city driving
IAT Reading: 71-75 deg
Idle
IAT Reading: 75 deg slowly increasing to 80


Overall, intake temperatures for both applications were 10-15 degrees above ambient during highway driving and 18-24 degrees above ambient in city/idle driving.

So for those concerned with purchasing cold air intakes, the difference between an aluminum intake tube and stock intake tube had little to no change to the air intake temperatures at operating speeds/idle.

Also, it should be noted that I tested the C&L with and without the air box. The main difference in temperatures without the air box was +2 degs in highway and city driving and the at idle temperatures increased more quickly and rose to 90 deg. The bottom line, having separation between the engine and the air filter will help increase the amount of time it takes to heat up the air filter due to hot engine air. Think of it as housing insulation.

From a performance standpoint, I see it as more reasonable to say that your HP gains from aftermarket Cold Air Intakes is not because it pulls in cold air, but rather it increases the amount of air available to the engine and reduces the restriction of air compared to the stock setup.

Hope this helps your decision on Cold Air Intakes and helps eliminate some of the fear factors.
you are correct i say
 

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I think you are partially correct but getting the coldest air possible to that less restrictive intake is the key I believe.

I have the c&l and I also did some datalogging and what I found to be the biggest problem that coincided with my concerns was that at low speed when floorboarding it the iat reading would jump up until you had enough speed to push some air in to cool things down. I believe it sucks so much air that it gets as much as it can from the desired path and has to pull more from the engine bay which instantly makes the iat hot. That same reading was right in line with the doggy feeling off the line or low speed throttle jabs that were uninspiring for the known power under the hood.

I don't think there are great leaps to be made in intakes for mostly stock cars but I do think getting the air into the motor in the straightest and least restrictive path possible coupled with gathering said air from a source that is completely sealed from the engine bay heatsoak is the ticket.
 

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Discussion Starter #8 (Edited)

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Interesting figures! I hope you consider collecting some more data once the summer months roll in, again. Got to admit, sub-60 deg ambient temps kind of helps the whole situation along on its own. ;) When you are surrounded by nothing but hot air, that's where heat soak really takes a toll, imo.

I would also concentrate on city driving tests (since hwy driving tends to arrest the condition itself out of reliable, constant air flow), beyond 20 min. If you get to sitting still in traffic a few times after that point, there are few sources left for local sources of cooling, and that is when the intake temps rise up considerably. After the 20 min point of vehicle running, you should be into at least the 1st/2nd cycle of the radiator fluid exchange. Once the fan gets to blowing with the radiator at full temp, the hot air soak circus gets cooking inside there.

I'm not suggesting that the temps would really be that different between different intake parts, but I would target those scenarios where heat contamination would really see a heavy stress test.
I have done Datalogging during warm months 80*and sitting at lights and stop and go it was nothing to see IAT's climb up to 120*-130*. at one point I just let it sit there to see how high it would go and it went to 147*.

Once the engine bay gets heatsoaked it is hard for the temps to recover

Another thing I noticed was going from cold start up it would take about 15-20 minutes before the IAT's would really start to go up.

But then again my IAT sensor is a **** hair away from a red hot cast 90mm throttle body and a gigantic hunk of Aluminum (6.1 Intake )
 

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With the measures I have been investigating, the optimal scenario of constant cooling flow at hwy speeds the IAT read is showing 3-5 deg above whatever the ambient temp is on the dash readout. City driving seems to stay fairly close to this (maybe a 10 deg swing) within the first 25 min of driving. I don't really have good data for >25 min of city driving, since that is usually how long my in-town trips last.

Jumping back into the car after it has been parked after a drive is when I see some pretty hot iat temps. The iat may still be reading 90-100 deg just from the latent heat after it sits parked for maybe 3-4 hrs. Then driving around a little bit, doesn't really change much for low throttle settings. I can get it to cool down to 80 deg or so with some brief surges of high throttle (as it evacuates all of that old air sitting in the intake), but how long can you really do that w/o the car going to lightspeed? Then it just slowly rises back to 100 deg or so. If I am really stuck in traffic just idling and baking, then I see those ridiculous rises into the 120-130 range (and beyond). It only happens on rare occasion in the 60 deg whether lately, but it does happen.

I'm still working on more "stuff", but it still seems pretty far off from getting to that 3-5 deg above ambient behavior for park and go, city driving.
 

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With the measures I have been investigating, the optimal scenario of constant cooling flow at hwy speeds the IAT read is showing 3-5 deg above whatever the ambient temp is on the dash readout. City driving seems to stay fairly close to this (maybe a 10 deg swing) within the first 25 min of driving. I don't really have good data for >25 min of city driving, since that is usually how long my in-town trips last.

Jumping back into the car after it has been parked after a drive is when I see some pretty hot iat temps. The iat may still be reading 90-100 deg just from the latent heat after it sits parked for maybe 3-4 hrs. Then driving around a little bit, doesn't really change much for low throttle settings. I can get it to cool down to 80 deg or so with some brief surges of high throttle (as it evacuates all of that old air sitting in the intake), but how long can you really do that w/o the car going to lightspeed? Then it just slowly rises back to 100 deg or so. If I am really stuck in traffic just idling and baking, then I see those ridiculous rises into the 120-130 range (and beyond). It only happens on rare occasion in the 60 deg whether lately, but it does happen.

I'm still working on more "stuff", but it still seems pretty far off from getting to that 3-5 deg above ambient behavior for park and go, city driving.
You are so right seeing 3-5 degrees above ambient is about impossible in city driving

And latent heat when this big ass 6.1 aluminum intake and 90mm throttle body gets hot it stays hot even with a bag of ice on it.
And look how close the IAT sensor is to all that heat.

I shut off the car and go in a store or something the IAT sensor just pics up all that heat and temps go right up.

At lest with the composite 5.7 intake it cools off fairly quick

Sometimes I swear this thing is still hotter than the rest of the engine the next morning

 

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Well that's the kicker- I am running the composite intake and observing the readings I described. ;) So it seems that the composite intake isn't really that immune to heat soak anymore than the big aluminum one, believe it or not. The modes of heat conduction may differ, but the overall end result seems to be not that different given the cumulative effects of engine bay exposure.
 

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Does anybody know if it has ever been asked to the SRT Engineers if there is a preferred IAT range the hemi tolerates with only gradual reduction in performance as temps increase, after which it falls off a cliff beyond a certain temp? I think that would be an important piece of information in defining a target of how good is "good enough" when it comes to the search for cool air.
 

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That would not surprise me- nice info! I think this is a worthy question to throw in at the next SRT session.
 

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Wouldn't the key be to re-locate the IAT sensor closer to the filter to get 'colder' temp readings?

Also I've heard that the PCM samples the air temp from the IAT and intake manifold (or was it TB air temps?) and only at intervals for adjustments.
 

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Discussion Starter #18
So more datalogging done on air intake temperatures.



Just a few observations, I believe the BWoody IAT relocation might be getting heat from the radiator fan at idle. That is why you see the rapid increase of temperatures as the vehicle is not moving compared to the others. However, once the vehicle is at speed, the air temperatures are very consistent and smooth.
In comparison, the C&L without air box which is similar to the BWoody (no air box but IAT relocated), at 70mph, the air intake readings are, in general, lower.

More datalogging to follow as we await the Stack Performance Bullet intake.

Some of my expectations of the bullet will be a very smooth air flow reading and an air temperature reading that isn't affected by the radiator fan.
 

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What were engine or coolant temps,did the fans ever come on.

I don't think its hard for any CAI to have good IAT's at 40*-50* going down the highway at 70mph
x2......the key is good IAT's when you are idling at the tree after the burnout box.That will gain you max torque when it's time to launch the car at the track.Same as when you are sitting in traffic.
 
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