IAT2 ranges 40-50* above ambient with HE/fans

[99cobraUgotbit]

I have a C&R HE with fans. Just recently got an Aero Force gauge and can keep track of peramators. My IAT2s are always 50* and above while driving. I have seen where others claim 30* above ambient. It's 65* today and I'm ranging between 110-120* IAT2. I also have a 170* thermostat. Any way to get it cooler or am I missing something? I used a mix of coolant and water. Should I go straight distilled water?

 

[Pribilof]

Check to make sure your intercooler pump is still running.

I have VMP triple pass, 170 t-stat, 13/14 grills, 50/50 coolant mix and I run around 30 degrees above ambient I(monitored with Aeroforce guage).

 

[Catmonkey]

If you're seeing 140* temps on 90* days, then I think you probably have a problem somewhere. There are a lot of reasons that you could see a bigger disparity on cooler days. There's a lot of heat under that hood and hot coolant is being circulated through the manifold. What are your coolant temps with the lower thermostat?

A few things to check would be to make sure the pump is running, that you can see coolant circulating through the degass tank and there are no kinks in the coolant hoses. An abundance of bugs in the heat exchanger can also affect its efficiency.

You could go straight water, but you need to be diligent in adding antifreeze when it gets cooler. The intercooler can burst in the intake manifold if the water freezes. The intake is a bitch to remove and the only way to replace an intercooler.

 

[HillbillyHotRod]

As said check the flow. Also make sure the fans are working.

 

[jdt1970]

I am not a expert but I can pass on what I was told. I have a similar set up and I was told below 160 is good. I live in FL and mine runs around 130 while driving and even higher if parked with the engine and fans running. I have a 170 thermostat and triple pass HE with 3x capacity tank. Temp in Fl this time of year is 80-90.

 

[bFoxGt500]

I also have the C&R with 170 stat. I generally run similar temps above ambient. My HE fans are always on. When cruising on the highway I will typically be about +40F. I sitting in traffic, it can be +50-60F. I monitor my coolant at the same time with the Aero gauge. Going to distilled water has not done me much good that I can really note. I keep trying to get these coolant temps down because I have heat control issues in this summer Texas heat when doing HPDE events and have not yet found the best solution. I do recommend you continuously monitor those two parameters though as I have had both go overheat on occasion. A couple weeks ago, my HE pump quit on me and if I had not been watching my gauge, it would have been ugly.


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[Catmonkey]

I have something of interest I'm going to post pretty soon. Unless you've torn into the intercooler system, you'd probably be amazed that the tubes running from the manifold adapter to the intercooler are necked down to something just over 1/2". There are two 3" tubes. The entrance to the manifold adapter is at least that diameter. I opened my tubes up to 5/8", as well as the manifold adapter in hopes of getting more coolant through the intercooler. I didn't go larger than that because most of the metal fittings in the intercooler system are the same i.d. Whether that translates in something beneficial remains to be seen.

 

[99cobraUgotbit]

My pump is fine and I have flow.

I hear VMP HE is usually 30* above ambient but would like to hear from C&R HE users where they are at above ambient. Atleast to compare the two. Maybe I don't have an issue and that VMP is a tad better?

Bfox- what peramator is for coolant?

 

[Catmonkey]

Bfox- what peramator is for coolant?

If you're thinking intercooler coolant temps, it doesn't exist. However, you can get a temp sender from AeroForce and install it in the intercooler system with something like this.

This is an adapter made by Autometer. However, once the sensor is installed, it becomes a restriction. I ended up getting a 1.25" adapter tube and some silicone hose adapters from 3/4" to 1 1/4". I'll post up a pick.

 

[fishpick]

While I'm not a Cobra / GT500 owner - I can tell you I have been fighting high IAT's with my SC setup (like 50*+ over ambient) and it's NOT the HE or the IC efficiency - for me it's really JUST the underhood heat being consumed by the intake and fed to the engine - if I "get on it" so I'm really sucking in the underhood air - where I'm generating boost (which makes heat) - I actually see my temps go DOWN because the external air is cooler than than the under hood air and I have gulped all the "heated" air down.

This seriously sounds silly - but I have found my IAT's in general are "lower" over all - the harder I drive the car - because I move more air under the hood by virtue of the car "eating" it and keeping fresh air coming in...

All things equal with ambient and engine temps - the IAT's will be 50* high when "around town" and like 35-40* over ambient at highway speeds... and drop to 20-30 if I'm jammin on the accelerator and managing the gears so I'm seeing boost on the gauge and KNOW I'm pulling a ton of air in.

I'm adding some fans to the H/E and opening up the grill a bit more this weekend... but it's possible you are seeing the same things I'm seeing.

 

[RBB]

Are you in boost when you're seeing these temps? Keep in mind that IAT2 is the temperature measured after the air from the supercharger has passed through the intercooler. When the boost bypass is open, the air is getting dumped directly into the intake and bypassing the intercooler. That said, an IAT2 reading of 120 does seem a little high when you're cruising around on a 65* day.

 

[Catmonkey]

While I'm not a Cobra / GT500 owner - I can tell you I have been fighting high IAT's with my SC setup (like 50*+ over ambient) and it's NOT the HE or the IC efficiency - for me it's really JUST the underhood heat being consumed by the intake and fed to the engine - if I "get on it" so I'm really sucking in the underhood air - where I'm generating boost (which makes heat) - I actually see my temps go DOWN because the external air is cooler than than the under hood air and I have gulped all the "heated" air down.

This seriously sounds silly - but I have found my IAT's in general are "lower" over all - the harder I drive the car - because I move more air under the hood by virtue of the car "eating" it and keeping fresh air coming in...

All things equal with ambient and engine temps - the IAT's will be 50* high when "around town" and like 35-40* over ambient at highway speeds... and drop to 20-30 if I'm jammin on the accelerator and managing the gears so I'm seeing boost on the gauge and KNOW I'm pulling a ton of air in.

I'm adding some fans to the H/E and opening up the grill a bit more this weekend... but it's possible you are seeing the same things I'm seeing.

Actually, it's what you should be seeing. What most don't realize is when the boost by-pass is open, which is mostly idle, cruise and light throttle, air is going directly into the intake manifold and very little airflow is going through the intercooler. When the boost by-pass slams shut on heavy throttle, air is forced through the intercooler. You'll notice the three small inlets in the smaller section of the top of the intake. What sits above it is the by-pass throttle blade.

Here is the inside of the intake with the intercooler removed. You can see the ports at the very top of the pic is the route from the by-pass section.

Now, this is the inside of the intake manifold with the intercooler in place.

You can see from the pics that air coming in through the by-pass ports is going around the intercooler and doesn't have much change of getting cooled by the walls of the intercooler. The walls of the manifold are quite hot. The longer you drive the hotter it's going to get. Bottom line is monitoring your IAT2 temps while you are at idle or cruise speeds isn't a very effective way to measure your intercooler system. The true test of the intercooler is to monitor what the IAT2 does when you open the throttle and get into boost.

 

[fishpick]

Actually, it's what you should be seeing...

...The true test of the intercooler is to monitor what the IAT2 does when you open the throttle and get into boost.

@Catmonkey : I know that bypass temps are higher, and why, and how the bypass works - BUT - the issue still remains the PCM is gonna pull timing when it sees high numbers for IAT - regardless of if the bypass is open or closed (and I'm using IAT as the post-boost value, so in my posts IAT and IAT2 are interchangeable, I'm not all fancy with 2 temps like you Cobra / GT500 guys). So "cruising" or idling at the line before the tree goes green - pretty sure is going to increase the IAT's while the blower is on bypass and and cause initial timing to be pulled until your IC gets a chance to cool enough air for the PCM to give it back to you...
So if you are cruising - and the Corvette guy rolls up - and you want to show him he overpaid... you are not "at your best" if your IAT's are sitting at 135-ish because you have been bypassing for a long time...

And, again, the fact I see the temps plummet when I jam on things and generate boost shows the IC/HE is working just fine (which is why I said that above)... And why driving more aggressively keeps the temps down...

That said, an IAT2 reading of 120 does seem a little high when you're cruising around on a 65* day.

And therein lies the challenge - right? Those temps are higher than one would like for just "cruising" - so - I go back to what I suggested to the OP - it could just be that the under hood air temps are making things look hot!

 

[Catmonkey]

@Catmonkey : I know that bypass temps are higher, and why, and how the bypass works - BUT - the issue still remains the PCM is gonna pull timing when it sees high numbers for IAT - regardless of if the bypass is open or closed (and I'm using IAT as the post-boost value, so in my posts IAT and IAT2 are interchangeable, I'm not all fancy with 2 temps like you Cobra / GT500 guys). So "cruising" or idling at the line before the tree goes green - pretty sure is going to increase the IAT's while the blower is on bypass and and cause initial timing to be pulled until your IC gets a chance to cool enough air for the PCM to give it back to you...
So if you are cruising - and the Corvette guy rolls up - and you want to show him he overpaid... you are not "at your best" if your IAT's are sitting at 135-ish because you have been bypassing for a long time...

And, again, the fact I see the temps plummet when I jam on things and generate boost shows the IC/HE is working just fine (which is why I said that above)... And why driving more aggressively keeps the temps down...

Not knowing what you have, it's hard to answer, but being able to isolate the entrance of your CAI from underhood heat is probably where you need to focus your efforts, if that's possible. Insulating the CAI tube might also have some merit, unless your injesting a lot of under hood air. If we had some sort of phenolic spacers available to isolate your intakes from the cylinder heads, it might help too. I know the GT500 pumps exiting coolant from the block and heads into passages that are part of the intake manifold and that doesn't help either.

 

[RedVenom48]

Try running your car with the rear hood seal removed. Helps improve the airflow through the engine bay and cools things off a tad. Just need to be careful when you wash your car is all.

 

[fishpick]

@Catmonkey - I don't want to hijack the OP's thread... I was just offering some thoughts is all
(I'm a 2012 GT Whipple 2.9 FF)

Try running your car with the rear hood seal removed. Helps improve the airflow through the engine bay and cools things off a tad. Just need to be careful when you wash your car is all.

I'm adding HE fans this weekend to suck more air into the engine bay, trimming sections of the grill, and then - yeah - looking at that hood seal and thinking about it... but know the second I do that - I'm caught in a massive downpour...

 

[RedVenom48]

You should be fine in a storm. Nothing on the backside of the engine should water get down there though.

Of course, im not really anal about my engine bay cleanliness. Performance is all that matters. But others may be so only do it if you want max performance and underhood temps.

 

[Sirhc7897]

My 2011 GT500 with the CR Dual fan HE routinely ran IAT2's 30 degrees above ambient.

If I idled for a bit (drive thru, stagnant traffic, etc.) it would creep up to 40-50 above ambient but would cool quickly back to around 30 above once I got moving again.

I had 170 t stat as well.


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[99cobraUgotbit]

Are you in boost when you're seeing these temps? Keep in mind that IAT2 is the temperature measured after the air from the supercharger has passed through the intercooler. When the boost bypass is open, the air is getting dumped directly into the intake and bypassing the intercooler. That said, an IAT2 reading of 120 does seem a little high when you're cruising around on a 65* day.

Yea I would say in and out of boost on the freeway. No lower then 110*. I did notice that my HE does the job because after being parked I saw really high temps and once I started driving it cooled way down quickly.
Just thought I would have cooler temps. Last year at 95*-100* I was heat soaked. I heard anything over 140* you pull timing and I'm already on a mild tune due to only having 91pump. Just not looking forward to being heat soaked this summer when I have invested in an aftermarket HE.

What over cooling mods are out there?

 

[Islandcat]

I have a c&r on my car, and at 65 ambient, my iat2 would be between 90-100, depending on how long I had been running and how many times I got on it. The longer you cruise it seems the more heat that is retained so it creeps up a lil.