Engine/Transmission (1998.5 - 2002) Anyone monitoring intake air temp?

[GOT-Torque]

What range of temperature do you see? under full load and max boost, how high can it get?



Thanks...

 

[Boosted6]

Mine has been running around 130 at wot here lately with ouside temps in the mid to upper 80's. I did clean my Intercooler, radiator and evap with some coil cleaner and the a/c is ice cold and the truck temp stays down and today I only seen around 115 IAC...

 

[Gary - K7GLD]

What range of temperature do you see? under full load and max boost, how high can it get?



Thanks...

In the past, I've read of temps under heavy load and high boost that was up in the 300 degree range - hot enough to bake bread...



Dunno what it typically is in our trucks...

 

[y-knot]

i have been for the last 5-6 years. It is a none issues, as I have never seen mine go past 110°, never. It usually runs 10-20° cooler then outside temps. It's such a boring gauge, I just recently took it out and replaced it with a dual needle air gauge to monitor tank and bag pressure.

 

[Gary - K7GLD]

i have been for the last 5-6 years. It is a none issues, as I have never seen mine go past 110°, never. It usually runs 10-20° cooler then outside temps. It's such a boring gauge, I just recently took it out and replaced it with a dual needle air gauge to monitor tank and bag pressure.

You ARE talking about measured temps at the INTAKE manifold, right at the engine, and AFTER the intercooler? The intecoolers might be GOOD - but good enough to cool the intake air even LOWER than outside ambient?



I'd have to see it...

 

[Silver_Ram]

I monitor my Intake Air Temp through my Attitude monitor. I am assuming it somehow takes the reading from the IAT sensor VIA the trucks computer. With the outside temps between 80 & 90 degrees, the Intake Air Temp was 130 dergrees.



I installed an ATS Arc Flow Intake Manifold last week & the Intake Temperature dropped to 110 degrees. My Intake Temp seems to run 20 to 30 degrees warmer than the outside temps & the type of driving (street or highway). The Intake Temp climbs as high as 145 when I use my exhaust brake, but it goes back down fairly quick.

 

[TAbbott]

"It usually runs 10-20° cooler then outside temps. "



Not possible unless you're running water/meth or something similar to further cool the charge air beyond what a normal aftercooler will do. Think you might have a bad guage.

 

[y-knot]

Sorry I'm only reporting what I've been monitoring for the last 5-6 years!!



A believe me, nothing is impossible.



ps. Yes I was measuring the air temp just before it entered the engine. I was using a Auto Meter Intake Air Gauge.



And Yes I have used them many other times on a dragster I had that was also Turbocharged. My current project, Project Cobra'33, is Supercharged and I am installing a data acquisition system on it from Innovate Motor sports. I'll have read-outs from Intake air temp, both before and after the super charger, at least 2 EGT sensors, 4-O2 sensors, fuel pressure both supply side and return, oil temp and pressure, water temp, transmission temp, boost pressure, 2-cylinder head temps, battery voltage, and throttle position travel.

 

[Gary - K7GLD]

Sorry I'm only reporting what I've been monitoring for the last 5-6 years!!



A believe me, nothing is impossible.



ps. Yes I was measuring the air temp just before it entered the engine. I was using a Auto Meter Intake Air Gauge.



And Yes I have used them many other times on a dragster I had that was also Turbocharged. My current project, Project Cobra'33, is Supercharged and I am installing a data acquisition system on it from Innovate Motor sports. I'll have read-outs from Intake air temp, both before and after the super charger, at least 2 EGT sensors, 4-O2 sensors, fuel pressure both supply side and return, oil temp and pressure, water temp, transmission temp, boost pressure, 2-cylinder head temps, battery voltage, and throttle position travel.

WELL, then you have achieved an engineering and physics miracle - being able to cool one medium to an even cooler temperature than the one used to accomplish that change - using your technology, we'd never need to use refrigerant in our air conditioning systems again, just use air-to-air intercoolers, and duct the resulting cooler than ambient air into the truck cab!

 

[BarryG]

I have had the same experience as silverram monitoring the stock AIT sensor through the trucks computer with the Attitude.

 

[PC12Driver]

WELL, then you have achieved an engineering and physics miracle - being able to cool one medium to an even cooler temperature than the one used to accomplish that change - using your technology, we'd never need to use refrigerant in our air conditioning systems again, just use air-to-air intercoolers, and duct the resulting cooler than ambient air into the truck cab!

Almost every turboprop or jet aircraft that I can think of does not use refrigerant in its air conditioning system.



The Air Cycle Machine takes compressed air from the compressor section of the engine (hot), compresses it further (hotter yet), runs it through a air/air cooler, and then expands the air charge to a lower pressure (a few psi).



By compressing the air and making it a few hundred degrees warmer as it crosses the intercooler, the temperature gradient is steep enough to pull a bunch of heat out of the air charge. Then when the pressure is dropped to near ambient, the resulting temperature drop (Bernoulli's principle at work) results in some very cold air. Cold enough that warm engine bleed air is added back into the air charge to keep the system from freezing up. It'll cool the cabin in Dallas in July, so we're using 100*+ air to cool the cabin to a comfy 74*.



The ACM looks like a tubocharger. The compressor side is driven by the cooler, more dense air passing through the turbine side after it travels through the intercooler.



What Y-knot sees makes perfect sense. In cruise, we carry 5-10 psi of boost. This air is heated slightly, run across an intercooler where the charge air is brought down to near ambient temps. Then it hits the plumbing going into the engine where velocity will increase (velocity increases, pressure decreases, temperature decreases - Bernoulli's again) dropping the temperature. And if you drop near-ambient temperatures there's a good chance you'll end up with below ambient.



Obviously there's a lot of factors at play here, but I wouldn't say that it's impossible to have lower than ambient charge air temps. No miracle, just basic physics.

 

[drury]

PC12Driver, that is a fascinating post, and it makes sense, except I'm not clear on why the velocity increases as the air goes into the engine?



My own personal experience with Edge Attitude monitoring on an '06 exactly mirrors what Silver Ram is seeing on his '02, and I've even got a Spearco Intercooler which ought to be cooling better than the stock IC. If Y-Knot's experience of lower than ambient temps is real, then I would love to know how to duplicate it on my engine.

 

[BILLVO]

Where is the IAT sensor located on an 02? I was going to pull it out along with the MAP sensor and clean them as I used oiled filters in the past and I found oil in my aftercooler when I put new boots on It came from the airsep I had on with the new bigger turbo Now upgraded to the afe stg 2 dry. The MAP sensor looked like new but I could not find the IAT. I looked for several minutes even with a mirror but saw nothing.

 

[Gary - K7GLD]

What Y-knot sees makes perfect sense. In cruise, we carry 5-10 psi of boost. This air is heated slightly, run across an intercooler where the charge air is brought down to near ambient temps. Then it hits the plumbing going into the engine where velocity will increase (velocity increases, pressure decreases, temperature decreases - Bernoulli's again) dropping the temperature. And if you drop near-ambient temperatures there's a good chance you'll end up with below ambient.



Obviously there's a lot of factors at play here, but I wouldn't say that it's impossible to have lower than ambient charge air temps. No miracle, just basic physics.

YUP - but these trucks are NOT airplanes flying at 20,000 feet or better altitude, and hundreds of miles per hour - your example is fine, just doesn't really match or fit our application!



I'm very familiar with venturi effect and similar - but the PSI readings taken on our trucks, both for boost gauges and the IAT are AT the intake manifold, that is, our WHOLE INTAKE SYSTEM is pressurized, and at nearly the same PSI - and while there is SOME PSI head loss across the intercooler, I seriously doubt there is enough venturi-type effect or PSI differential anywhere between the turbo and intake valves in our engines to supply a 10-20 degree drop in relation to outside air temps!



And I'll say it again in OUR truck application, running our intercoolers thru 100 degree outside ambient air temps at normal cruising speeds is VERY unlikely to result in air at the intake into the engine, of 80-90 degrees.



BUT, I have temp sensors of my own - and now know what my NEXT truck experiment will be! :-laf:-laf



By the way, I mean NO disrespect to Ynot or his comments - just suspicious of his findings, or perhaps the way they were arrived at - but will do some checking of my own - who knows, I may well end up eating Crow - AGAIN!



Regards - Gary

 

[Gary - K7GLD]

Where is the IAT sensor located on an 02?

It's tucked in between the fuel filter and rear of the engine on the driver's side of the engine - sorta hard to get to...

 

[BILLVO]

It's tucked in between the fuel filter and rear of the engine on the driver's side of the engine - sorta hard to get to...

The only sensor in that area is the MAP sensor there is no other sensor in that area on mine except for the temp sensor on the back of the head. Is it possible it doesn't have one? I will look close behind the filter itself.

 

[Gary - K7GLD]

The only sensor in that area is the MAP sensor there is no other sensor in that area on mine except for the temp sensor on the back of the head. Is it possible it doesn't have one? I will look close behind the filter itself.

We may be talking about the same sensor - it's been a while since I poked around in that area - and sometimes I get my acronyms scrambled...

 

[PC12Driver]

PC12Driver, that is a fascinating post, and it makes sense, except I'm not clear on why the velocity increases as the air goes into the engine?

The air charge is moving the slowest as it passes through the big, wide intercooler. Then it necks back down into the plumbing going into the intake horn and the speed picks back up. Kinda like 4 lanes of traffic merging into one.

 

[PC12Driver]

The only sensor in that area is the MAP sensor there is no other sensor in that area on mine except for the temp sensor on the back of the head. Is it possible it doesn't have one? I will look close behind the filter itself.

The MAP and the IAT are neighbors. They both tap into the driver's side of the head towards the back. The IAT sensor is just a couple of inches farther back...

 

[PC12Driver]

YUP - but these trucks are NOT airplanes flying at 20,000 feet or better altitude, and hundreds of miles per hour - your example is fine, just doesn't really match or fit our application!



I'm very familiar with venturi effect and similar - but the PSI readings taken on our trucks, both for boost gauges and the IAT are AT the intake manifold, that is, our WHOLE INTAKE SYSTEM is pressurized, and at nearly the same PSI - and while there is SOME PSI head loss across the intercooler, I seriously doubt there is enough venturi-type effect or PSI differential anywhere between the turbo and intake valves in our engines to supply a 10-20 degree drop in relation to outside air temps!



And I'll say it again in OUR truck application, running our intercoolers thru 100 degree outside ambient air temps at normal cruising speeds is VERY unlikely to result in air at the intake into the engine, of 80-90 degrees.

I was using the ACM example to demonstrate the "engineering and physics miracle" that you didn't think was possible a few posts back. I found it entertaining that when you so eloquently challenged Y-Knot's findings you inadvertently described the air conditioning system on jet aircraft to a "T".



You're right, I just went outside and checked, and my truck is in fact NOT an airplane flying at 20,000 feet. Thanks for pointing that out though just in case someone was confused...



My example was just to prove the principle and maybe throw out some trivia to entertain the TDR readers, since we're all interested in mechanical stuff at one level or another. The point of my post was that if the system in my plane can take a 103 psi air charge at 530* and knock it down to below freezing by using 100* air while sitting stationary on a ramp, then just maybe the air charge in our trucks could end up being a few degrees cooler using the exact same principle, and very similar components.



He's measuring the temps in the intake horn, not from the IAT sensor stuck on the hot engine. The air charge wouldn't be heated very much at cruise boost levels. The intercooler will cool the charge temps down to about ambient. And there is a pressure drop, which *will* drop the temps. Why wouldn't Y-Knot's findings seem possible?