Sanity check - IAT2

[paluka21]

Hi all,

Wanted to inquire about "normal" thresholds of temperatures people are seeing during summer months while running the A/C.
Quick rundown; sitting in parking lot for 5 minutes with high speed A/C running, 88 degrees ambient temperature I was seeing IAT2 temperatures climb to 152 degrees with engine coolant temp at 200 degrees and air inlets reading up to 162 degrees. Granted the car is idling with A/C on and I would expect IAT1's to be high, I'm a little concerned about the 152 IAT2 temp.
Typically, my IAT2 temps are 40-50 degrees above IAT1 while driving around in 80-85 degree heat; example IAT1 85 degrees, IAT2 would read 130-135 degrees and will climb if I get into boost hard.

 

[Mojo88]

I monitor IAT2/ECT constantly with my AeroForce dual gauge. Normally run around 125/190, tad lower on cooler days, tad higher on hot days (as in your post).

I've never let my car run for 5 minutes just sitting, just something I don't ever do. I avoid heavy traffic areas too, so I don't do much stop & go driving.

 

[Catmonkey]

On high vacuum operation, with the blower by-pass open, you don't have that much air going past the intercooler. Most of it is going straight down into the intake to where the air is simply going around the exterior of the intercooler. If air coming into the supercharger is 162*, I don't see it bringing air in the intake getting much too lower than that, especially at idle. What CAI are you running because it's obviously ingesting a lot of heated under hood air? What happens once you're moving and not going into boost?

 

[paluka21]

On high vacuum operation, with the blower by-pass open, you don't have that much air going past the intercooler. Most of it is going straight down into the intake to where the air is simply going around the exterior of the intercooler. If air coming into the supercharger is 162*, I don't see it bringing air in the intake getting much too lower than that, especially at idle. What CAI are you running because it's obviously ingesting a lot of heated under hood air? What happens once you're moving and not going into boost?

I'm running a PMAS 120 / plastic CAI.

When I'm driving around out of boost IAT2's are usually 40-50 degrees above ambient or IAT1 readings. For example, I've seen 70 degree day read 70-71 degrees IAT1, but IAT2 was at 120-125 degrees. Obviously goes up if I get into boost.

 

[MastaAce03]

Seems like your IAT2s are running a little higher than they should. I’m consistently 30degrees above the temp outside. Couldn’t tell you why. I personally wouldn’t be beating on it too hard with IAT2 temps above 130 but to each their own. Hope you figure it out.

*** I do have an after market heat exchanger with fans. If you don’t, get one.***


Sent from my iPhone using Tapatalk

 

[Beercules]

Mine can get pretty hot on a hot day also. Black car. Just heat soak for me. I wish someone would make some kind of exhaust heat shield to keep hot air at the bottom of the engine bay instead of warming up the intake tract.

You can always spend some money with j2 fabrication and be done with the heat soak.

 

[paluka21]

I have upper and lower grilles on my car to protect the heat exchanger and radiator. Perhaps that causes the car to run a little warmer. But it still seems as though the IAT2 is 10 degrees or so too warm.

 

[sleek98]

Are you using the bucket/shroud that comes with the pmas?

I didn’t for a while and noticed my iat2 were higher.

 

[Black Cobra '99]

First, do you have an aftermarket heat exchanger?
Second, while stationary those temps are normal and it does not matter really because you're at vacuum. With an aftermarket heat exchanger its expected to see 30-35 degrees above ambient.

 

[paluka21]

Are you using the bucket/shroud that comes with the pmas?

I didn’t for a while and noticed my iat2 were higher.

Yes sir, I am.

 

[jchristena]

I'm running a PMAS 120 / plastic CAI.

When I'm driving around out of boost IAT2's are usually 40-50 degrees above ambient or IAT1 readings. For example, I've seen 70 degree day read 70-71 degrees IAT1, but IAT2 was at 120-125 degrees. Obviously goes up if I get into boost.

Those are about the same as my results. Stock HE. But after some driving around...out of the boost in traffic, I usually don't see the 30 degree delta that everyone else does. It's usually closer to 45 degrees.

Everyone swears by these aftermarket HEs. When I first got the car, Van told me that the stock HE is so good that I wouldn't see much, if any, gain changing it. Perhaps I misunderstood what he was saying because it seems like 30 degrees is everyone's norm. Here in Austin, I don't get much boost weather so staying around 30 degrees would be nice in the summer.

 

[Robot_trainer]

Hi all,

Wanted to inquire about "normal" thresholds of temperatures people are seeing during summer months while running the A/C.
Quick rundown; sitting in parking lot for 5 minutes with high speed A/C running, 88 degrees ambient temperature I was seeing IAT2 temperatures climb to 152 degrees with engine coolant temp at 200 degrees and air inlets reading up to 162 degrees. Granted the car is idling with A/C on and I would expect IAT1's to be high, I'm a little concerned about the 152 IAT2 temp.
Typically, my IAT2 temps are 40-50 degrees above IAT1 while driving around in 80-85 degree heat; example IAT1 85 degrees, IAT2 would read 130-135 degrees and will climb if I get into boost hard.

If its a stock HE without a fan, I'd expect that. As long as it comes down when your moving. For me, I'd keep it out of boost until it does start coming down. Probably feel pretty "soft" until it does come down. ECU will probably pull timing until it does.

 

[Catmonkey]

Yes sir, I am.

How effective is it? I'd use some modeling clay and see if you have big gaps around the hood enclosure and the heat shield. Not having seen one up close, are there areas where under hood air has no problem going down the intake tube?

 

[Catmonkey]

I googled the intake to see what the heat shield looked like and came up with a pic you posted.

While it's a little hard to get the best perspective from a single photo, I don't see that it would do a real effective job of keeping super heated air from being ingested into the intake if you're sitting in traffic. In fact it looks like the filter area sits higher than the insulation, so I have to wonder if the foam insulation even contacts the hood. Sitting idling doesn't make that much difference, but how fast the system can recover once moving would be more important.

 

[paluka21]

I googled the intake to see what the heat shield looked like and came up with a pic you posted.

View attachment 1497425

While it's a little hard to get the best perspective from a single photo, I don't see that it would do a real effective job of keeping super heated air from being ingested into the intake if you're sitting in traffic. In fact it looks like the filter area sits higher than the insulation, so I have to wonder if the foam insulation even contacts the hood. Sitting idling doesn't make that much difference, but how fast the system can recover once moving would be more important.

Very good observation. I will have to investigate to see if contact is being made to seal that area off. If not, I may purchase a used airbox and alter it as others have done to accommodate the PMAS.

 

[Catmonkey]

The newer version of JLT's heat shield can be purchased individually which would probably work with a lot of the aftermarket CAIs out there. They did that so their older version, which left a lot to be desired aesthetically and functionally, could be upgraded. Ford Racing used the OEM heat sheild in their Whipple kit and I replicated it with a Whipple 123mm MAF. I cut down a used JLT tube to mate the two since I'm using a TVS.

You might look at whether your heat shield uses the factory grommets and that they're in place, or if there is a way to extend them if there is a gap between the hood and the foam. McMaster Carr also carries foam like that which might be thicker.

 

[Robot_trainer]

I googled the intake to see what the heat shield looked like and came up with a pic you posted.

View attachment 1497425

While it's a little hard to get the best perspective from a single photo, I don't see that it would do a real effective job of keeping super heated air from being ingested into the intake if you're sitting in traffic. In fact it looks like the filter area sits higher than the insulation, so I have to wonder if the foam insulation even contacts the hood. Sitting idling doesn't make that much difference, but how fast the system can recover once moving would be more important.

I would bet there are some gaps between the hood and air box both with OEM and aftermarket. You'd probably have to fabricate something if you want to eliminate it. I would imagine once you are moving the cold air coming in displaces the hot underhood air. If you watch the IAT1, you can see the temp drop to almost ambient levels.

 

[50stangpower]

My temps looked crazy too before I put a fanned HX on the car. Once I changed the HX out it made a huge difference, even with the factory 13 HX.

 

[Catmonkey]

I would bet there are some gaps between the hood and air box both with OEM and aftermarket. You'd probably have to fabricate something if you want to eliminate it. I would imagine once you are moving the cold air coming in displaces the hot underhood air. If you watch the IAT1, you can see the temp drop to almost ambient levels.

More than likely that's probably true. I think the key is to minimize what heated air goes down the intake. Once you're moving the dynamics will change, but the only way you can tell how much it changes is to either data log both, or have gauges that monitor both sensors. If you're seeing stupid hot IAT2s at every traffic signal and it goes down 30*-40* after you start moving, I think your heat shield ain't shielding heat.

 

[biminiLX]

Those are about the same as my results. Stock HE. But after some driving around...out of the boost in traffic, I usually don't see the 30 degree delta that everyone else does. It's usually closer to 45 degrees.

Everyone swears by these aftermarket HEs. When I first got the car, Van told me that the stock HE is so good that I wouldn't see much, if any, gain changing it. Perhaps I misunderstood what he was saying because it seems like 30 degrees is everyone's norm. Here in Austin, I don't get much boost weather so staying around 30 degrees would be nice in the summer.

Van is right the stock HE is a great core and large, BUT no fans. I bought a Shelby S1000/Revan top shelf HE with fans but after cutting out the huge steel bumper support for light tubular, I ended up adding fans to the stock HE.
Datalogging this weekend in 90 degree weather, my IATs were 110-115 with 3-4 WOT blasts on a 15 min drive. Just ambient water in the trunk tank and I was happy with that 20-25 delta WOT. It was near ambient at cruise but not much stop and go.
My point is the fans are key to prevent heat soak in street driving.
That and E85 allowing 24 degree timing WOT pulls leaving rubber all over the place
-J