Engine Heat with AC On Options

[HardHead93]

It got a little warm today in southern New Mexico so today was the first day I drove the 3sgte swapped Celica in stop and go traffic with the AC on. Normally without the AC on, the engine temps bounce between 189 and 199 degrees F. When I turned the AC on it climbed to 209 degrees in the course of 5 minutes before I turned the AC off. Once I turned the AC off the temp quickly dropped back into the normal range in about another 2-3 minutes. I am reading the temps off an aftermarket water temp gauge with the sensor on the upper radiator hose. Below is a picture of the type of gauge I am using. It is a Glowshift MaxTow water temp gauge.


When that gauge reads 215 degrees the stock dummy temp gauge in the car starts moving towards the H. I am running an Ebay 2-row radiator with aftermarket fans and I have a FMIC. Should I keep the aftermarket fans or go back to a stock radiator with stock fans? Also, the Ebay radiator is pretty dirty from constantly taking it in and out of the car during the build process, could that be the culprit? Is there something else I should check on that may be causing the engine temps to climb with he AC on? Below is a picture of the 2 different radiators.


Is there really an advantage to running a 2 row radiator with a 3sgte?

This post has been edited by HardHead93: Mar 17, 2017 - 7:33 PM

[Bitter]

The stock fans will move WAY more air. The AC adds a fairly large heat load IN FRONT of the radiator meaning it's getting pre-heated air through it, that's why having high airflow is so critical when running the AC system AND trying to keep the car cool. I think swapping to stock fans will probably take care of the issue, but it would also be a good idea to clean the AC condenser and radiator with some AC coil cleaner per bottle directions.

Some cars have pusher fans on the AC, you could piggy back a single slim fan to the stock fans via a relay and mount it up front to blow inward (between the IC and condenser , there could be some airflow drop through the thicker radiator core, but that's a lot of added electrical load for possibly no gains in cooling.

[HardHead93]

The stock fans will move WAY more air. The AC adds a fairly large heat load IN FRONT of the radiator meaning it's getting pre-heated air through it, that's why having high airflow is so critical when running the AC system AND trying to keep the car cool. I think swapping to stock fans will probably take care of the issue, but it would also be a good idea to clean the AC condenser and radiator with some AC coil cleaner per bottle directions.

So stock fans with the stock radiator? I tried to put the stock fans on the 2 row radiator and they do not fit.

[Bitter]

Cause the rad is too thick or the mounting studs don't line up?

[HardHead93]

Cause the rad is too thick or the mounting studs don't line up?

The mounting studs do not line up. I broke one factory fan and had to go get a second one from the junk yard. I just put the factory radiator back in with the factory fans and it seems to be cooling really well.

[Bitter]

It shouldn't be hard to use some aluminum bar stock to make a bracket to bolt to the studs and then bolt the fans to the bar stock, should you later desire the bigger radiator.

[HardHead93]

So I ran the stock radiator with the stock fans yesterday and the heat issue during stop and go driving with the AC on got better but then I started having worse heat issues with sustained driving on the freeway. My water temps were climbing to 213-215 degrees F when before the highest they would go with freeway driving was 204. I think this is pointing to an air flow issue. If I don't figure out how to get more air to the radiator it doesn't matter what fans or radiator I am using. After doing some research and talking to a couple of people I know with turbo cars (they drive Honda Civics but I will forgive them ), it looks like the front mount intercooler is blocking air flow to the radiator.




When I installed the intercooler I kept the crash bar in place because the fog lights attach to it. A lot of FMIC installs on our cars have removed that bar. I can see that being a culprit for blocking air flow. Is that true? If I remove the crash bar, is there a way to mount the fog light brackets so I can keep them? The whole point of my turbo build was to have a more powerful engine but not at the cost of losing functionality (fog lights, cruise control, AC, etc.). As you can see from the first picture I also installed an additional bumper duct to help with cooling but it is not enough. I have switched back to the 2-row radiator because it seems to cool the best for the majority of the type of driving I do. Any ideas for fixing this problem would be greatly appreciated.

This post has been edited by HardHead93: Mar 19, 2017 - 11:12 AM

[Bitter]

I think you need to keep the crash bar, it's super important should there be an impact.

I would ditch the fog lights and move the oil cooler to one side in the fog light opening, should get enough airflow and small fan on a thermostatic switch could be attached if needed.
Then the next step would be to get the stock fans mounted to the 2 core radiator and open the area above the crash bar in the bumper so airflow can bypass the FMIC to the radiator.




You could also look into water spray systems to mist water through the FMIC or onto the radiator to add cooling on a demand basis, like maybe trigger it off the radiator fans so when they turn on you get a mist of water sprayed over the radiator for additional cooling. Evaporating water off the IC and radiator can dump a bunch of extra heat, but it would need to be a pulsed spray, like 1 second on, several seconds off. They make systems for that, but it's been years since I read about them.

This post has been edited by Bitter: Mar 19, 2017 - 12:57 PM

[HardHead93]

I think you need to keep the crash bar, it's super important should there be an impact.

I would ditch the fog lights and move the oil cooler to one side in the fog light opening, should get enough airflow and small fan on a thermostatic switch could be attached if needed.

Sorry, the picture with the bumper off is old. The oil cooler was removed when I went from a 5sfte to a 3sgte. I will look to widen that vent I cut in the bumper and potentially install another. I agree, the crash bar is very important, I will keep it. Ideally I would like to get this bumper.


It has extra vents in it and would solve my air flow issues. The problem is I am not too sure about the Duraflex brand's quality and I hear a lot of those bumpers tend to crack really easy.

This post has been edited by HardHead93: Mar 19, 2017 - 3:13 PM

[Bitter]

Ever seen a GT4 front bumper?
http://www.6gc.net/forums/index.php?showtopic=63523
Look at how much more open space there is and that big extra opening up top, you need something like that.

[Box]

Anything under 240º is within operating spec on most any modern engine, so if it only gets up to 215º you're over worrying. Ideally you're in the 185-210º range on most engines. Thing is though the best place to read water temperature is in the head since it's most accurate, so odds are you're higher than what you're currently reading. You could go to a GT-Four bumper and hood as well as the TMIC if you could find one, it worked for every factory GT-Four so you know it'll work for you. Though many do fine with a FMIC and the GT-Four bumper and hood.

[HardHead93]

Anything under 240º is within operating spec on most any modern engine, so if it only gets up to 215º you're over worrying. Ideally you're in the 185-210º range on most engines. Thing is though the best place to read water temperature is in the head since it's most accurate, so odds are you're higher than what you're currently reading.

When i was running a standalone on my 5s and could pull temp readings right off it, I had this sensor/gauge in place and it was pretty close to the same as what was coming off the stock temp sensor on the coolant neck (my gauge was reading 1-2 degrees higher). On the 3s the stock sensor is in the same place on the coolant neck that comes off the cylinder head so I am probably in the same boat. What ever my gauge is reading is pretty close to what the ECU is seeing. It is good to know that the temps (around 215 degrees F) I am seeing could have me worried for nothing.

You could go to a GT-Four bumper and hood as well as the TMIC if you could find one, it worked for every factory GT-Four so you know it'll work for you. Though many do fine with a FMIC and the GT-Four bumper and hood.

I already have a custom vented hood.


I like the GT-Four bumper but it seems like everyone is doing that conversion who has a 6th gen Celica. I would like to use a bumper that gives a different look than everyone else but still provides the venting I want. Is there any reputable company that makes a quality aftermarket bumper of the style I am looking for? I am planning to repaint the car later this year and I would do the bumper then.

[slavie]

Stock fans are better - they have scoops to pull the air from the entire surface of the radiator vs the aftermarket coolers on the 2-row you have. I mean, just looking at those fans on alum rad, they do not apply to at least a third of the radiator.
If you could fabricate a way to attach stock fans, that would of course be your best bet.

Aside from that, you either need to increase inflow, or reduce the pressure on the back so that the air can outflow more easily. First would require chopping up the bumper or getting an aftermarket one. I know you said you don't like the GT4 bumper, but those are really good - crash bar is much narrower (if you get the whole front bits, not just the cover) and you have a lot more air inflow.

Another idea is to look at your engine splash shields (under engine covers). A lot of people junk them thinking they block airflow. But, toyota put it there for a reason - smoother airflow under the car will create lower pressure under the car and allow the air from the engine bay to escape more easily. Removing the under engine covers creates turbulence, and may make matters worse. You can search around the internet and there are threads where people measured the temp differences and say a drop in temps WITH the covers.

Finally, your FMIC looks pretty restrictive. Not sure how much you can do here, but just pointing it out. GT4 A2W intercooler is more like a regular radiator rather than having flat bars like the A2A FMIC.

Hope this helps.

[Box]

The Duraflex bumper you posted earlier is a knock off of the C-ONE bumper, but an authentic C-ONE bumper is hellaciously rare.

[HardHead93]

The Duraflex bumper you posted earlier is a knock off of the C-ONE bumper, but an authentic C-ONE bumper is hellaciously rare.

Ahh man! I really like the look of that bumper.

[Box]

There out there, but usually they're overseas and shipping is a fortune. That and it seems like most don't know how to package anything so it ends up arriving broken more often than not. You could do like some people have done and combine the GT-Four and facelift bumper, "SS-IV" is usually what it's called if memory serves correctly.

[Bitter]

I still think if you dump the fogs and put two air scoops there with some duct you could get air up to the top of the radiator bypassing the FMIC and might be OK, certainly cheaper to try that out than to get a new bumper and paint for the new bumper. if it doesn't work then you've at least tried.

[Box]

I want to say someone used to make vents for the Celica specifically you cut out the regular bumper and then they fit in place over the cutout, they were sorta in a GT-Four style.

[HardHead93]

I widened the opening on the carbon fiber bumper vent I installed. It seems to provide the additional needed air flow that bypasses the intercooler with the AC on. The water temps don't seem to be climbing as high anymore. That was in 90 degree weather. The true test will be when we start having 100+ degree days during the summer.

[Box]

Or in order to satisfy my OCD and provide additional cooling you could install a second vent mirrored to the first one.