Cold air intake IATs spiking

[Bash74]

This is the actual truth
 
I bought a "Cold" Air Intake and felt the truck being more sluggish
 
Did a log, Hello, 120*F intake temps
 
I reinstalled my AirAid Intake Tube with the stock AirBox and Filter, truck went back to normal
 
My 2 cents is get rid of those intakes and reinstall the stock one. And if you want more flow, get a Geen Filter or any drop in filter for the stock airbox
 
I have had the AirAit MIT for a couple of years now, and im happy with the performance of the truck
 
 
Cheers

That's what I have. The stock air box, better flowing filter, and the Airraid tube. It all just helps it breath better which is all that is needed.

Sent from my SM-G975U1 using Tapatalk

[truckguy82]

On 6/13/2020 at 11:12 PM, Grumpy Bear said:

There use to be an exhibit at the museum of science and industry. A chess board where every square was a different material. Each square about 4 X 4. The materials were heated from below to all be at the exact same temperature. You put your hand on one at a time and they all felt like they were quite different. Wood felt warmer than glass and so on. The material will change the amount of time it takes to reach under hood temperature but soak any material long enough at the same temperature and it will be at the same temperature. I wouldn't worry about it. 

Yes but in the real word the r-value is exactly what’s important because all that matters is how fast energy can be transferred.

 

It’s why your outside surface of your freezer will always be near ambient temp.

 

The only time r value does not matter is if said object is exposed to the temps on all sides of it.

 

 

 

 

[lucas287]

16 hours ago, truckguy82 said:

Yes but in the real word the r-value is exactly what’s important because all that matters is how fast energy can be transferred.

 

It’s why your outside surface of your freezer will always be near ambient temp.

 

The only time r value does not matter is if said object is exposed to the temps on all sides of it.

 

 

 

 

How many air changes are occurring within the volume of the intake tube over a given period of time? Should be pretty simple to calculate. An engine is an air pump right? Inhales and exhales, that's it. Increase RPM and it breathes faster. A 5.3 is 325 cubic inches, which as you know is the volume of all 8 cylinders combined. It takes two complete revolutions of a typical 90 degree crank to complete the firing of all cylinders. So, in one engine revolution it has inhaled approximately 162.5 cubic inches. This is assuming 100% volumetric efficiency though. With the engine idling at 500 RPM, that's 8.333 revolutions per second, or, approximately 4 complete firings of all 8 cylinders. 4 x 325 = 1,300 cubic inches. But at idle VE is probably only 50%, so let's cut that in half and say 650. That's 650 cubic inches of volume every single second. 

 

Hold that thought. 

 

What's the volume of the intake tube? Let's assume it's 4" diameter and 24" long. It's actual volume is probably smaller, but I'm being generous and using round numbers. That yields a volume of ~300 cubic inches. 

 

That means about 2 air changes occur in the intake tube every single second. And this is just at idle. At 2,000 RPM there are 15 air changes occurring every single second. 

 

This should illustrate that heat soak of the intake tube itself doesn't matter one bit. You cannot heat air that's moving at that kind of velocity. The increase in IAT is from poor sealing of intake box itself. Heat soak is a real problem but the intake tube isn't the culprit. 

 

Oh and someone check my math and logic please.

[truckguy82]

26 minutes ago, lucas287 said:

How many air changes are occurring within the volume of the intake tube over a given period of time? Should be pretty simple to calculate. An engine is an air pump right? Inhales and exhales, that's it. Increase RPM and it breathes faster. A 5.3 is 325 cubic inches, which as you know is the volume of all 8 cylinders combined. It takes two complete revolutions of a typical 90 degree crank to complete the firing of all cylinders. So, in one engine revolution it has inhaled approximately 162.5 cubic inches. This is assuming 100% volumetric efficiency though. With the engine idling at 500 RPM, that's 8.333 revolutions per second, or, approximately 4 complete firings of all 8 cylinders. 4 x 325 = 1,300 cubic inches. But at idle VE is probably only 50%, so let's cut that in half and say 650. That's 650 cubic inches of volume every single second. 

 

Hold that thought. 

 

What's the volume of the intake tube? Let's assume it's 4" diameter and 24" long. It's actual volume is probably smaller, but I'm being generous and using round numbers. That yields a volume of ~300 cubic inches. 

 

That means about 2 air changes occur in the intake tube every single second. And this is just at idle. At 2,000 RPM there are 15 air changes occurring every single second. 

 

This should illustrate that heat soak of the intake tube itself doesn't matter one bit. You cannot heat air that's moving at that kind of velocity. The increase in IAT is from poor sealing of intake box itself. Heat soak is a real problem but the intake tube isn't the culprit. 

 

Oh and someone check my math and logic please.

I’ve had that exact thought for years. Yeah it would not be significant. But you add in the throttle body, heads, intake manifold, air filter housing, that’s quite a bit of hot surface area.

 

Now keep in mind that you can actually change the temp of fast moving air. Simply look at air-air and air to water intercoolers. They are obviously way different than an intake tube though. And certain things that I would assume not matter at all end up mattering alot.

 

Like who would think hot headers would heat up an engine bay when at 60mph the air in your engine bay is getting replaced like 5 times a second

 

Yeah i don’t think an intake tube would do diddly squat unless it had fins on the inside and outside and was designed to transfer heat.

 

 

[lucas287]

1 minute ago, truckguy82 said:

I’ve had that exact thought for years. Yeah it would not be significant. But you add in the throttle body, heads, intake manifold, air filter housing, that’s quite a bit of hot surface area.

 

Now keep in mind that you can actually change the temp of fast moving air. Simply look at air-air and air to water intercoolers. They are obviously way different than an intake tube though.

 

Yeah i don’t think an intake tube would do diddly squat unless it had fins on the inside and outside and was designed to transfer heat.

 

 

You do make a good point about intercoolers,...hmm. I might have to jump down that rabbit hole

[truckguy82]

7 minutes ago, lucas287 said:

You do make a good point about intercoolers,...hmm. I might have to jump down that rabbit hole

Well compared to the intake tube, an intercooler probably has like 3x slower moving air, with 10x the interior surface area and 50x the exterior surface area.