heat exchanger coolant temps/efficiency

[rojizostang]

thanks for all the input.

too many posts to try and quote, but to summarize, I find my iat2f's in line with those related to in previous posts regarding ambient temps and intake air temps, and the dual and triple pass heat exchangers. this information helps quite a bit, actually, thanks.

I am aware of the appropriate pid's to monitor as far as datalogging is concerned. I real time monitor (as a gauge pod) those mentioned earlier...iat2f's, engine coolant and measured afr banks 1 and 2

I have the live link soft ware installed, but I haven't done any actual recording of the data, and then forwarding it to the tuner.

I'm not trying to break any new ground, just make an informed decision regarding an upgrade. As is, it appears that moving to the afco unit wouldn't net the desired results, which are to keep the ecu from pulling timing as intake temps rise.

it's not a race car, just a hobby, and I enjoy chasing these things down and trying to figure them out, if possible.

FWIW, I'm running actually a hodge-podge of heat exchangers. The one behind the bumper that came with the blower, and then I added the larger roush unit in front of the radiator, I then added a 14'' fan behind that, and lastly I added another heat exchanger in front of the upper roush unit that measures something like 2x26x7, if memory serves correctly. I probably have about $250 invested in the add on units.

Is this an in line device you have with a gauge on the dash or means of datalogging or is it simply a hand held probe type device you are putting in the HE res and checking the temps with the hood up while the car idles?

it's an in line device with a digital gauge attached that provides real time monitoring. It can be installed in the cabin, but I have elected not to. it actually splices into the cooling loop.

thanks for all your help, everyone.

 

[Department Of Boost]

120 to 150 degrees is pretty normal. Mine never goes over about 155, even while racing (road course) and under boost a lot of the time. Same goes for heavy traffic driving in about 105 degree weather.

Water temps?!?!?!

 

[Department Of Boost]

thanks for all the input.

I don't have time to sort through everything here.

What HE are you running?

What pump are you running? The real 13' GT500 pump or the CWA50?

What are you IC system water temps post HE compared to ambient?

What do you see for IAT's at WOT at 10psi?

 

[01yellerCobra]

I'm not trying to break any new ground, just make an informed decision regarding an upgrade. As is, it appears that moving to the afco unit wouldn't net the desired results, which are to keep the ecu from pulling timing as intake temps rise.

I think you're looking at it wrong. A heat exchanger isn't going to keep the ECU from pulling timing at temps rise. That's a function in the tune. It doesn't know what heat exchanger you're running. Just that your IAT's are hitting a certain temp and that's when it's supposed to pull timing. What the upgraded heat exchanger will do is make it take longer to hit those temps and then recover faster after those temps are hit.

IMO moving to a bigger heat exchanger would help you. Especially if you can find one that can handle what your current set up of three is doing.

I know it's a different car, but I have an Afco dual pass in my Cobra. A couple weekends ago I was stuck in traffic without a working high speed fan. My IAT's got up to 140 degrees while I was moving along at a snails pace. Once traffic broke and I got up to about 75-80 my temps came down within about 5 miles. And normal cruising temps for me are 105-115. Depending on ambient temps. This day happened to be a 90+ degree day.

 

[redfirepearlgt]

I think you're looking at it wrong. A heat exchanger isn't going to keep the ECU from pulling timing at temps rise. That's a function in the tune. It doesn't know what heat exchanger you're running. Just that your IAT's are hitting a certain temp and that's when it's supposed to pull timing. What the upgraded heat exchanger will do is make it take longer to hit those temps and then recover faster after those temps are hit. .

Correct here. However the larger HE will HELP keep the IAT2 temps down below the set point at which timing begins being pulled IAW with knock sensor data PID. Depending on application and tuner this is usually 135 -150 degrees (IAT2 setpoint)from my experience.

OP - I commend your HE setup and the time you have taken to make it work on a budget. So I am curious. Are the heat exchangers plumbed in parallel or series? I would assume they are plumbed in parallel since they are stacked one atop the next if I understood your description properly. ON the other hand if tied in series and laid out correctly you effectively have a triple pass unit. With that amount of surface area and flow path length a larger HE coolant pump may be as much benefit as anything if you are using the Roush original. As you are learning, more surface area more heat displacement ability. I venture to guess that your setup is as efficient as most dual or triple pass units just as a hunch. Maybe better.

 

[skwerl]

Having three different heat exchangers plumbed in series probably results in a lot more flow resistance. Perhaps the pump might be overworked with such a setup. How is your flow with all those units plumbed in?

 

[408Stang]

Air temp is what I was referring to.

 

[Department Of Boost]

I REALLY need to get my A2W IC system article finished.....................................

 

[rojizostang]

I don't have time to sort through everything here.

What HE are you running?

What pump are you running? The real 13' GT500 pump or the CWA50?

What are you IC system water temps post HE compared to ambient?

What do you see for IAT's at WOT at 10psi?

Well I know you don't want to sort thru everything, so I'll address this post separately

I think you're looking at it wrong. A heat exchanger isn't going to keep the ECU from pulling timing at temps rise. That's a function in the tune. It doesn't know what heat exchanger you're running. Just that your IAT's are hitting a certain temp and that's when it's supposed to pull timing. What the upgraded heat exchanger will do is make it take longer to hit those temps and then recover faster after those temps are hit.

IMO moving to a bigger heat exchanger would help you. Especially if you can find one that can handle what your current set up of three is doing.

I know it's a different car, but I have an Afco dual pass in my Cobra. A couple weekends ago I was stuck in traffic without a working high speed fan. My IAT's got up to 140 degrees while I was moving along at a snails pace. Once traffic broke and I got up to about 75-80 my temps came down within about 5 miles. And normal cruising temps for me are 105-115. Depending on ambient temps. This day happened to be a 90+ degree day.

Ok, stated badly on my part. I understand it's a function of the tune. The tune starts pulling timing at 120 degrees

Correct here. However the larger HE will HELP keep the IAT2 temps down below the set point at which timing begins being pulled IAW with knock sensor data PID. Depending on application and tuner this is usually 135 -150 degrees (IAT2 setpoint)from my experience.

OP - I commend your HE setup and the time you have taken to make it work on a budget. So I am curious. Are the heat exchangers plumbed in parallel or series? I would assume they are plumbed in parallel since they are stacked one atop the next if I understood your description properly. ON the other hand if tied in series and laid out correctly you effectively have a triple pass unit. With that amount of surface area and flow path length a larger HE coolant pump may be as much benefit as anything if you are using the Roush original. As you are learning, more surface area more heat displacement ability. I venture to guess that your setup is as efficient as most dual or triple pass units just as a hunch. Maybe better.

series

Having three different heat exchangers plumbed in series probably results in a lot more flow resistance. Perhaps the pump might be overworked with such a setup. How is your flow with all those units plumbed in?

the flow appears to be quite violent in the expansion tank. I have the Piersberg cwa50 pump...it's the pump ford uses for the '13 and later gt500's, but wired a little differently

 

[rojizostang]

i don't have time to sort through everything here.

What he are you running?

a combination of 3 exchangers

what pump are you running? The real 13' gt500 pump or the cwa50?

cwa50

what are you ic system water temps post he compared to ambient?

ah, now we are down to brass tacks. This is where the specific information is that i'm looking for. Today, ambient temp was 75, post heat exchanger coolant temp was 81


what do you see for iat's at wot at 10psi?

i don't really know the answer to this one. I haven't really recorded a datalog yet, and it's too dangerous to look at iat's at wot and hold the vehicle on course!

...

 

[rojizostang]

a pic for the curious

this shows only the upper two heat exchangers. the 14'' fan is behind them. there is also a lower but smaller heat exchanger behind the bumper. the device used to measure the temps isn't visible. This is actually an older picture. I took a new one but couldn't find it after downloading it to one drive. oh well.

this is actually a mustang, even though in the picture it might look like an f150.

(extreme measures must be taken to protect this information from the policia that move random threads to the non mustang media section, lol)

 

[redfirepearlgt]

How are the engine coolant temps with both of those units stacked in front of it?

 

[rojizostang]

How are the engine coolant temps with both of those units stacked in front of it?

low to mid 190's.

 

[BruceH]

Why not monitor iats? That's the important parameter. As long as the iats are within reason when compared to ambient everything is working well.

 

[rojizostang]

Why not monitor iats? That's the important parameter. As long as the iats are within reason when compared to ambient everything is working well.

I am.

the question is about determining whether or not a different heat exchanger would be a beneficial upgrade. since there's a direct relationship between heat exchanger coolant temps and iat's, measuring coolant temps certainly seems wise in order to make a decision. the question is how much expectation there would be with an upgraded heat exchanger toward moving coolant temps closer to ambient. it's all in the thread, if you read it, respectfully.

 

[Pentalab]

Well I know you don't want to sort thru everything, so I'll address this post separately



Ok, stated badly on my part. I understand it's a function of the tune. The tune starts pulling timing at 120 degrees



series



the flow appears to be quite violent in the expansion tank. I have the Piersberg cwa50 pump...it's the pump ford uses for the '13 and later gt500's, but wired a little differently

Typ most tuners will set the tune to start to pull timing at 135 F. Some will be as high as 150 F. 120 F seems too low, never heard of one set that low. IMO, for max effectiveness, I would plumb the HE's in parallel, not series. If you put 2 x identical roush HE's one behind the other, and plumbed in parallel, the flow would slow down through each individual HE. You would dump more heat from each HE.

 

[redfirepearlgt]

I agree. 120 degrees is very low. But then again if its a default Roush tune nothing would surprise me. Roush default tunes are for dyno results only.

 

[Department Of Boost]

How are the engine coolant temps with both of those units stacked in front of it?

Not even close to an issue. I used to run the below setup on my blue car. That is a 3.5" thick HE core you're looking at. It was 100% sealed so all the air that got to the rad had to go through the HE first. I did a track day when it was 102deg out. My IC water temps were in the 130's so the rad was getting some seriously hot air. I was seeing 220-225deg engine coolant temps. I know that seems high but it's not really. Even NA you will see temps that high at the road course without some serious race car cooling. And those NA cars aren't making 600rwhp so they have a much smaller heat load.

All I had for engine cooling was a off the shelf Afco rad. Everything else was stock.

 

[Department Of Boost]

a combination of 3 exchangers

That's obviously not helping water flow. How much is it hurting is anyone's guess.

cwa50

Do you have it wired up the tricky way so it runs full speed?

"A jumper from pin 4 (Battery+) to pin 3 (PWM) will run the pump at full speed. See the picture showing the pin assignments. Connect ground to pin 1, 12v to 3 and 4 there will be a 3 to 10 second delay before the pump starts."

ah, now we are down to brass tacks. This is where the specific information is that i'm looking for. Today, ambient temp was 75, post heat exchanger coolant temp was 81

That's about as good as you're going to get without going batshit crazy with the system. And it's pretty damn good. That reveals what you have is a water speed issue. Cool/faster water means lower IAT's.

You also may have a cavitation issue. Have you seen what the 13' GT500 does to solve the cavitation issue? They use their same ol degas tank, but they have a special hose that "bypasses" it. The hose "T's" off before the tank and then "T's" back in after it. The bulk of the water bypasses the tank and the tank truly becomes a degas res. You want to do this unless you're running a HUGE tank with some baffling.

You don't have a HE issue at this point. They're doing the job of making cool water. You need to speed that water up and make sure you're not cavitating. Once that is taken care of you will strip more heat at the IC and your water temps will go up. If your system gets a lot better at stripping heat from the IC you will eventually need a bigger HE to keep up.

what do you see for iat's at wot at 10psi?

i don't really know the answer to this one. I haven't really recorded a datalog yet, and it's too dangerous to look at iat's at wot and hold the vehicle on course!

Time to data log.

 

[redfirepearlgt]

^^^ Good stuff. Has DOB experimented with triple pass units or double pass with regard to finding the optimal recirc pump with respect to the typical 2300 TVS and kitted IC on Coyotes as well as 4.6 3v's? Standard kit degas bottle applies. I'll use 10 psi boost for reference.

So if I understand you correctly DOB, an increase in coolant flow (flow/velocity) improves IC heat removal. Now the HE must dissipate that heat. Is there a point at which flow/velocity surpasses the dissipation process in the HE side of the loop starts losing efficient ability to remove the heat before the coolant returns to the IC?