Stock Heat Exchanger Mod....lower IAT2 temps 40 degrees
07-06-2013, 02:30 PM
#1
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Thread Starter
Stock Heat Exchanger Mod....lower IAT2 temps 40 degrees when A/C is on
I recently started to tune my car myself, and noticed the IAT2 temps were alot hotter than my 03 Cobra with a water to air intercooler system very similar to the Cobalts.
After looking around a bit and verifying my pump was working fine, I noticed the heat exchanger was between the A/C condenser and the radiator. What in the world were GM engineers thinking here? The temps coming out of that A/C condenser are around 140 degrees with the A/C on! Since I live in Florida I have the A/C on almost all the time.
I was seeing IAT2 temps 15-25 degrees above IAT1 temps with the A/C off, which is ok, but not great.
With the A/C on, I was seeing IAT2 temps 40-50 degrees above IAT1 temps. This put my IAT2 temps while driving around town in the 140-150 range, which is really freaking hot. Hot enough that the computer was pulling 4-6 degrees of timing at all times. This makes the car sluggish as hell, and now I see why there are so many cooling mods for these cars.
So I figured the first thing I would do is move the heat exchanger in front of the A/C condenser. Turns out that the condenser will bolt right up to the radiator with the heat exchanger removed. And, using longer bolts, the heat exchanger will bolt right up to the A/C condenser. No new brackets are needed, just longer bolts. Like 4 inch long bolts.
You also have to bend the tubes on the heat exchanger so they will clear the bottom of the fan shroud, took a total of 5 minutes to do that.
The only thing that needs cut/modified is the air dam. You have to trim an inch or so off the corners so it will clear the bumper.
After doing this, I am seeing my IAT2 temps less than 10 degrees of IAT1 temps. After a full throttle pull through 2nd and 3rd, I only saw a tad over 120 degrees. That is an awesome temp. Also, with the A/C on, temps are less than 10 degrees of IAT1 now....not 40-50 higher anymore. This should make the car feel alot peppier while driving around town now.
And....this would be worthless without pics....so.....
8 degree temp difference between IAT1 and IAT2
After looking around a bit and verifying my pump was working fine, I noticed the heat exchanger was between the A/C condenser and the radiator. What in the world were GM engineers thinking here? The temps coming out of that A/C condenser are around 140 degrees with the A/C on! Since I live in Florida I have the A/C on almost all the time.
I was seeing IAT2 temps 15-25 degrees above IAT1 temps with the A/C off, which is ok, but not great.
With the A/C on, I was seeing IAT2 temps 40-50 degrees above IAT1 temps. This put my IAT2 temps while driving around town in the 140-150 range, which is really freaking hot. Hot enough that the computer was pulling 4-6 degrees of timing at all times. This makes the car sluggish as hell, and now I see why there are so many cooling mods for these cars.
So I figured the first thing I would do is move the heat exchanger in front of the A/C condenser. Turns out that the condenser will bolt right up to the radiator with the heat exchanger removed. And, using longer bolts, the heat exchanger will bolt right up to the A/C condenser. No new brackets are needed, just longer bolts. Like 4 inch long bolts.
You also have to bend the tubes on the heat exchanger so they will clear the bottom of the fan shroud, took a total of 5 minutes to do that.
The only thing that needs cut/modified is the air dam. You have to trim an inch or so off the corners so it will clear the bumper.
After doing this, I am seeing my IAT2 temps less than 10 degrees of IAT1 temps. After a full throttle pull through 2nd and 3rd, I only saw a tad over 120 degrees. That is an awesome temp. Also, with the A/C on, temps are less than 10 degrees of IAT1 now....not 40-50 higher anymore. This should make the car feel alot peppier while driving around town now.
And....this would be worthless without pics....so.....
8 degree temp difference between IAT1 and IAT2
Last edited by lwrs10; 07-06-2013 at 02:46 PM.
07-06-2013, 03:32 PM
#6
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Thread Starter
Nothing really yet. Ported blower and a ZZP CAI. I was logging the car to make sure everything was kosher before I slap a 2.8 pulley and 60's on it. Tune is still stock minus fixing the speedo because of a tire change and taking out the burst knock timing reducer these have stock.
07-06-2013, 05:03 PM
#10
Nothing really yet. Ported blower and a ZZP CAI. I was logging the car to make sure everything was kosher before I slap a 2.8 pulley and 60's on it. Tune is still stock minus fixing the speedo because of a tire change and taking out the burst knock timing reducer these have stock.
07-06-2013, 05:09 PM
#11
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Thread Starter
nope. I have a wideband on it, and have been logging with HP Tuners. It needs bigger injectors, but I am still safe. 11.2AFR WOT, and fuel trims are all under 2%. On the stock tune.
07-06-2013, 05:26 PM
#13
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Thread Starter
according to my temp gun, nope. The temps coming out of that heat exchanger are not very high.
yep. 246hp 221tq, corrected, on a dynojet.
yep. 246hp 221tq, corrected, on a dynojet.
Last edited by lwrs10; 07-06-2013 at 05:39 PM.
07-06-2013, 07:30 PM
#15
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07-06-2013, 09:59 PM
#16
Awesome information! I may do this soon. If anyone else tries i would be interested in the results. Likewise if i do get around to it, i will post mine! Thanks for the info!
07-06-2013, 10:14 PM
#17
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The real question is, can you do this on top of doing a ZZP S3 HE? Because the ZZP one sits in front, so theoretically you could have your stock one right behind the ZZP one.... this might give huge temp advantages to Stage 3 guys... but I wonder why Powell never did this? Or why it is not in the GM manual for tuning these things... you're telling me these have been out this long and no one has done this? Either way, great write up and its great to see someone still working hard!
07-07-2013, 08:24 AM
#22
quick question, is that 8* difference after a wot pull?
just wondering, because when i was stock, id see 10-15* over ambient before going wot. then it would almost always be 20-25 after putting it down
im just trying to decide if i really want to take the time to do this lol
definitely a cool idea though. id be much more willing to do this than buy cooling mods.
just wondering, because when i was stock, id see 10-15* over ambient before going wot. then it would almost always be 20-25 after putting it down
im just trying to decide if i really want to take the time to do this lol
definitely a cool idea though. id be much more willing to do this than buy cooling mods.
07-07-2013, 10:44 AM
#23
New Member
Thread Starter
quick question, is that 8* difference after a wot pull?
just wondering, because when i was stock, id see 10-15* over ambient before going wot. then it would almost always be 20-25 after putting it down
im just trying to decide if i really want to take the time to do this lol
definitely a cool idea though. id be much more willing to do this than buy cooling mods.
just wondering, because when i was stock, id see 10-15* over ambient before going wot. then it would almost always be 20-25 after putting it down
im just trying to decide if i really want to take the time to do this lol
definitely a cool idea though. id be much more willing to do this than buy cooling mods.
07-07-2013, 11:44 AM
#24
The real question is, can you do this on top of doing a ZZP S3 HE? Because the ZZP one sits in front, so theoretically you could have your stock one right behind the ZZP one.... this might give huge temp advantages to Stage 3 guys... but I wonder why Powell never did this? Or why it is not in the GM manual for tuning these things... you're telling me these have been out this long and no one has done this? Either way, great write up and its great to see someone still working hard!