Higher IATs than Expected?

[Bartlett]

Hello all, I'd like some feedback on these IATs given my RPMs. I did 4 pulls, with 3rd to 4th gear WOT twice, I believe.

My stats:

- 187mm crank pulley, and stock SC pulley
- 6500' DA
- 77 F ambient
- E20-E25 fuel (91 + 3.5ish gals of E85 - likely 70% ethanol)
- PLM heat exchanger (no reservoir, non-divorced, 50/50 coolant-to-water) (btw, PLM heat exchanger/kit quality is subpar)

https://i.imgur.com/lfwgvbc.png

I feel like I'm seeing some higher numbers than I should be seeing...but perhaps the 6500' DA is a contributor to that due to the air density affecting cooling efficiency.

Anyways, any thoughts? I'd like to keep IATs under 65 C, but they keep going to about 70, and on that last pull about 75 C. Most pulls were done within about 2-3 min of each other while driving on and off the "on-ramps".

Thanks

[socrates42]

what values are you using for logging, also what tool?

[Bartlett]

what values are you using for logging, also what tool?

VCDS and these values:

Engine speed
Accelerator position
Charge air pressure specified value-MAP_SP
Air mass
IGA_AD_1_KNK[5]
Ignition angle: actual
Intake air temperature
Intake manifold pressure: absolute
RFP_AV

[mdelmonico]

I have the PLM HX no reservoir and I see about a 30*-35* rise on a single 3rd gear pull.

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[Jester2893]

How did you bleed the setup? I just did my PLM instal with reservoir and noticed this car is tricky to bleed. I purchased an air coolant filler to pressure the system while I fill it to hopefully get rid of any air pockets.


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[cjw]

I just have the heat exchanger, non divorced. My logs on a 60 f day start around 48C end around 72C.

Edit: I just looked at a couple more, I think if I hit the 70's, that would be on the second 3rd gear pull. The other few logs I checked stayed in the lower 60's.

[awwturbo]

Just looking at my old stage 2 logs from July 2016, my WOT from 2-5 gears only saw an increase of about 19-20 degrees Celsius. I have a divorced unit so don't know if that is partly why, but yours do seem on the high side. On dual pulley, temps on a 3-4 gear WOT run see a typical 25-27 degree Celsius increase at the end of the run (41.25-60 degree Celsius on a 74F humid day).

[kelseysautobody]

Sorry you've run into quality issues with your HX, I don't think that's the norm. The packaging, quality and fit of mine was top notch.

I think what you are seeing is pretty normal for those ambient temps. Before I divorced the system and with a 50/50 mix I would see a 35-38*C rise in a 1/4 mile run if my IAT's started around 40C. I'm dual pulley and have the reservoir. Temps have been too high for me to get some apples to apples comparisons but I think divorcing my system and going with a water/water wetter coolant mix has helped quite a bit.

[Timkl25]

I have PLM kit with reserve tank with water/wetter and EPL stage 2. With 90F outside, I usually see 45C IAT during idle. Before I added the Varimax pump, I was able to get to IAT 75C after 2-3 pulls, after adding the pump, temps stay under 65C.

[mdelmonico]

I have PLM kit with reserve tank with water/wetter and EPL stage 2. With 90F outside, I usually see 45C IAT during idle. Before I added the Varimax pump, I was able to get to IAT 75C after 2-3 pulls, after adding the pump, temps stay under 65C.Did you divorce the system and replace the factory pump with the Varimax pump?

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[Timkl25]

Did you divorce the system and replace the factory pump with the Varimax pump?

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I didn't divorce the system, just added another pump near the reserv tank, AMS uses that set up.

[Bartlett]

Also, disclaimer to everyone...I believe it's a fact that cooling efficiency is reduced at my altitude. Here is some data (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091123.pdf) I found that led me to this conclusion.

I didn't do the math yet, but it's probably at least affecting it by a couple degrees C.


I have the PLM HX no reservoir and I see about a 30*-35* rise on a single 3rd gear pull.

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What are your cruising IATs? Seems like mine are about 50C.


How did you bleed the setup? I just did my PLM instal with reservoir and noticed this car is tricky to bleed. I purchased an air coolant filler to pressure the system while I fill it to hopefully get rid of any air pockets.


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Basically, I just installed the unit, connected everything, ran the car, added coolant/water to the reservoir, and checked the heat with the AC compressor off. And everything seemed good. I then checked the levels that night and the day after, and everything was good. It doesn't seem like one would need to do all this work to bleed the system. At least, not in my case. But, perhaps I'm missing something.


I just have the heat exchanger, non divorced. My logs on a 60 f day start around 48C end around 72C.

Edit: I just looked at a couple more, I think if I hit the 70's, that would be on the second 3rd gear pull. The other few logs I checked stayed in the lower 60's.

Hmm, starting at 52, I consistently hit basically 70C on every pull.


Just looking at my old stage 2 logs from July 2016, my WOT from 2-5 gears only saw an increase of about 19-20 degrees Celsius. I have a divorced unit so don't know if that is partly why, but yours do seem on the high side. On dual pulley, temps on a 3-4 gear WOT run see a typical 25-27 degree Celsius increase at the end of the run (41.25-60 degree Celsius on a 74F humid day).

So, you're saying 41-60C after that pull? That seems remarkably low.


Sorry you've run into quality issues with your HX, I don't think that's the norm. The packaging, quality and fit of mine was top notch.

I think what you are seeing is pretty normal for those ambient temps. Before I divorced the system and with a 50/50 mix I would see a 35-38*C rise in a 1/4 mile run if my IAT's started around 40C. I'm dual pulley and have the reservoir. Temps have been too high for me to get some apples to apples comparisons but I think divorcing my system and going with a water/water wetter coolant mix has helped quite a bit.

Glad to hear that yours was in good shape. I am working with PLM to get a replacement and maybe some other concession.

Divorcing the system, I've read is for running a higher water content in the SC loop and for making servicing the SC loop separately, easier.

What are your thoughts on the reservoir though? I have it as well, but I didn't install it. I felt like it wouldn't make much of a difference.


I have PLM kit with reserve tank with water/wetter and EPL stage 2. With 90F outside, I usually see 45C IAT during idle. Before I added the Varimax pump, I was able to get to IAT 75C after 2-3 pulls, after adding the pump, temps stay under 65C.


I didn't divorce the system, just added another pump near the reserv tank, AMS uses that set up.

Hmm...I was thinking about that booster pump or doing the CWA-300 pump (we have CWA-150). Maybe that will be my x-factor here. I'd like to stay under 70C at all times during about 80F, because it can get to 95F here and I don't want to see 80C temps lol. I'm mainly concerned about longevity, because even at 75C, no timing was pulled.

[cjw]

Bleeding the system is pretty easy - 3 points and two are on the supercharger. Just be careful with the plastic bleed ports on the supercharger as they are known to break. Here 's a pic of the third bleed location taking from a how to from another forums.

http://i689.photobucket.com/albums/vv257/BRD-PREY/22_heater%20core%20bleed_zpse8npsmok.jpg

[mdelmonico]

My cruising temps in 60F-70F is around 30C-35C. I haven't driven it much since my leg is messed up. Hopefully tonight I can do more logging and see how it is in warmer temps.

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[brs2c]

http://i689.photobucket.com/albums/vv257/BRD-PREY/22_heater%20core%20bleed_zpse8npsmok.jpg

Cjw is right. Additionally, it is important to make sure you have someone holding RPM's around 2k, while bleeding.

[kelseysautobody]

I have PLM kit with reserve tank with water/wetter and EPL stage 2. With 90F outside, I usually see 45C IAT during idle. Before I added the Varimax pump, I was able to get to IAT 75C after 2-3 pulls, after adding the pump, temps stay under 65C.

Very interesting. Does the pump run at all times and do you have the OE pump mod done?

I completely re-routed my system when I divorced. I originally had the system routed per the instructions, (OE Pump -> SC intercoolers -> Top of HX -> Out the bottom of HX -> PLM Tank -> return to pump.) Figuring the coolant will be at its coolest right after it passes through the HX I currently have it routed OE pump > PLM tank > In bottom of HX > out top of HX > SC intercoolers > Return to pump. Where it returns to the pump I have a T connection that goes to a mini expansion tank.

[kelseysautobody]

Divorcing the system, I've read is for running a higher water content in the SC loop and for making servicing the SC loop separately, easier.

What are your thoughts on the reservoir though? I have it as well, but I didn't install it. I felt like it wouldn't make much of a difference.

Correct. I divorced the SC loop so I could more easily change my coolant mixtures with the seasons. I'm also looking for every last bit of cooling and every tenth of a second at the track but with your set up its probably not worth the hassle.

I would definitely add the reservoir. Between the reservoir, larger HX and lines it should add a gallon of capacity to the system. The more fluid the longer it takes to heat up and the lower your IAT's.

[theweebabyseamus]

My cruising temps in 60F-70F is around 30C-35C. I haven't driven it much since my leg is messed up. Hopefully tonight I can do more logging and see how it is in warmer temps.

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+1

[awwturbo]

So, you're saying 41-60C after that pull? That seems remarkably low.

It wasn't all that hot outside and it was a 2 gear pull.

https://docs.google.com/spreadsheets/d/1cqpfJSuEt1Y8m3etywX-196zb-UsXSL92VLCjXWw704/edit#gid=979968149

Check the logs out. I haven't cleaned it up, but just look for when the bypass valve stays as 0% and follow the IAT. This was taken at a 74F evening with higher humidity.

[Bartlett]

Bleeding the system is pretty easy - 3 points and two are on the supercharger. Just be careful with the plastic bleed ports on the supercharger as they are known to break. Here 's a pic of the third bleed location taking from a how to from another forums.

http://i689.photobucket.com/albums/vv257/BRD-PREY/22_heater%20core%20bleed_zpse8npsmok.jpg

Thanks! Is there a way where I can verify whether or not I need to do this? I don't believe I hear any bubbling noises and my coolant levels never dropped after the day of installation.


My cruising temps in 60F-70F is around 30C-35C. I haven't driven it much since my leg is messed up. Hopefully tonight I can do more logging and see how it is in warmer temps.

Sent from my SM-N950U using Audizine mobile app (http://r.tapatalk.com/byo?rid=87676)

Hmm, that's pretty low!


Cjw is right. Additionally, it is important to make sure you have someone holding RPM's around 2k, while bleeding.

Could this possibly be why my temps are higher? Is there a way to verify if I have air in the system? As mentioned, I don't believe I hear any bubbling noises and my coolant levels never dropped after the day of installation.


Very interesting. Does the pump run at all times and do you have the OE pump mod done?

I completely re-routed my system when I divorced. I originally had the system routed per the instructions, (OE Pump -> SC intercoolers -> Top of HX -> Out the bottom of HX -> PLM Tank -> return to pump.) Figuring the coolant will be at its coolest right after it passes through the HX I currently have it routed OE pump > PLM tank > In bottom of HX > out top of HX > SC intercoolers > Return to pump. Where it returns to the pump I have a T connection that goes to a mini expansion tank.

And your expansion tank is by the coolant reservoir? How much of a difference do you think your revised loop makes?


It wasn't all that hot outside and it was a 2 gear pull.

https://docs.google.com/spreadsheets/d/1cqpfJSuEt1Y8m3etywX-196zb-UsXSL92VLCjXWw704/edit#gid=979968149

Check the logs out. I haven't cleaned it up, but just look for when the bypass valve stays as 0% and follow the IAT. This was taken at a 74F evening with higher humidity.

Oh, but your peak is like 61C. Still seems pretty decent.

[kelseysautobody]

And your expansion tank is by the coolant reservoir? How much of a difference do you think your revised loop makes?

Yeah its kinda rigged up directly behind the headlight for now. I'm still testing the revised loop. It's not going to be an apples to apples comparison though because I switched from 50/50 (coolant/water) to 90/5/5 (water/water wetter/coolant.) With much warmer temps since I've logged last, IAT's do seem to be the same or lower so it appears to be helping.

https://i.imgur.com/svGqTtv.jpg

[Timkl25]

Very interesting. Does the pump run at all times and do you have the OE pump mod done?

I don't have the OEM Pump mod done, as the secondary pump is spliced into that for signal, and battery for power. So as soon as the car is unlocked( signal wire gets power) my pump kicks on.

[Bartlett]

Update:

70F and sunny outside.

Cruising for 10 min at 85mph = 31/32C the whole time. Oil temp hit 222F, so the engine was certainly warm.
Did 1 pull from bottom of 2nd to the top of 3rd and I hit 68C.
30 seconds later, it stayed at around 38C for about 2 min, then dropped to 36/37C.

How do those numbers look without a reservoir and with 50/50 coolant/water?

My readings were from a P3.

[bhvrdr]

Update:

70F and sunny outside.

Cruising for 10 min at 85mph = 31/32C the whole time. Oil temp hit 222F, so the engine was certainly warm.
Did 1 pull from bottom of 2nd to the top of 3rd and I hit 68C.
30 seconds later, it stayed at around 38C for about 2 min, then dropped to 36/37C.

How do those numbers look without a reservoir and with 50/50 coolant/water?

My readings were from a P3.

Not bad. If you divorce it, run 90% water with ww, and pump mod it you may get another 5c drop or so which would be great

Mike

[kelseysautobody]

Update:

70F and sunny outside.

Cruising for 10 min at 85mph = 31/32C the whole time. Oil temp hit 222F, so the engine was certainly warm.
Did 1 pull from bottom of 2nd to the top of 3rd and I hit 68C.
30 seconds later, it stayed at around 38C for about 2 min, then dropped to 36/37C.

How do those numbers look without a reservoir and with 50/50 coolant/water?

My readings were from a P3.

That's pretty much in line with what I saw at that 70F with 50/50. Until you really push the car cruising temps will stay lower. Then after a pull it will level off a few degrees higher after recovery.

[Bartlett]

Not bad. If you divorce it, run 90% water with ww, and pump mod it you may get another 5c drop or so which would be great

Mike

Thanks for the info. I am thinking of adding a reservoir and divorcing it, as you mentioned. I was thinking of doing the CWA-100 pump or a Varimax booster instead of the pump mod. Any thoughts on that?


That's pretty much in line with what I saw at that 70F with 50/50. Until you really push the car cruising temps will stay lower. Then after a pull it will level off a few degrees higher after recovery.

Hmm, sounds good. I was thinking I was really off with my temps, but maybe not.

-----------------------------------------------------------------------------------

Also, a few questions to anybody:

1) I noticed that my peak temps showed a massive discrepancy from cruising/no-load. To me, it seems like my cooling is effective, but not during the constraints of a pull (massive amount of heat in a short period)...So, I think that this could be an issue primarily with flow and liquid capacity?

2) Relating to the above question...Adding a reservoir..how important is this? Would I see maybe 4-5C shaved off peak temps?

3) Divorcing the loop. Many say it's not that beneficial, even a vendor or two (forgot their names), but it seems like the SC is what is really generating all of this heat. So, by using a 90ish% water and 5ish% water wetter mix in the SC loop, you can combat the main variable in heat across a stock S4 vs. modified S4. I'd imagine that, despite the aforesaid claims, this would help by at least 5C at peak.

4) At high altitude, it's known that convective cooling (I believe this applies to our heat exchanger scenario) is less effective due to the less dense area. In theory, perhaps this is true. But, in practice, there seems to be evidence pointing otherwise. Any insights?

Thanks for the responses

[theweebabyseamus]

Thanks for the info. I am thinking of adding a reservoir and divorcing it, as you mentioned. I was thinking of doing the CWA-100 pump or a Varimax booster instead of the pump mod. Any thoughts on that?



Hmm, sounds good. I was thinking I was really off with my temps, but maybe not.

-----------------------------------------------------------------------------------

Also, a few questions to anybody:

1) I noticed that my peak temps showed a massive discrepancy from cruising/no-load. To me, it seems like my cooling is effective, but not during the constraints of a pull (massive amount of heat in a short period)...So, I think that this could be an issue primarily with flow and liquid capacity?

2) Adding a reservoir..how important is this? Would I see maybe 4-5C shaved off peak temps?

3) Divorcing the loop. Many say it's not that beneficial, even a vendor or two (forgot their names), but it seems like the SC is what is really generating all of this heat. So, by using a 90ish% water and 5ish% water wetter mix in the SC loop, you can combat the main variable in heat across a stock S4 vs. modified S4. I'd imagine that, despite the aforesaid claims, this would help by at least 5C at peak.

4) At high altitude, it's known that convective cooling (I believe this applies to our heat exchanger scenario) is less effective due to the less dense area. In theory, perhaps this is true. But, in practice, there seems to be evidence pointing otherwise. Any insights?

Thanks for the responses

There's not much (if any) difference in divorcing the loop if you stay 50/50, as the majority of the gains come from reducing the anti-freeze ratio as you've touched on since there isn't any signifigant heat transfer between the two loops. Personally I read of enough issues with WW gumming up cooling systems that I decided to stay over 12% AF with no WW or run WW (Purple Ice, actually) with straight water.

[Bartlett]

There's not much (if any) difference in divorcing the loop if you stay 50/50, as the majority of the gains come from reducing the anti-freeze ratio as you've touched on since there isn't any signifigant heat transfer between the two loops. Personally I read of enough issues with WW gumming up cooling systems that I decided to stay over 12% AF with no WW or run WW (Purple Ice, actually) with straight water.

I see. I might skip it then and go for the reservoir. Anybody else kind enough to chime in on my questions?

Thanks!

[Bartlett]

Update: I really pushed the car today on an 84F day. IATs stayed around 38-39C while on the highway going 80mph. After a couple consecutive pulls, I was hitting 78-80C at the top of 3rd. This just seems way too hot, even for only having the heat exchanger.

[Jester2893]

[B][SIZE=3]


Basically, I just installed the unit, connected everything, ran the car, added coolant/water to the reservoir, and checked the heat with the AC compressor off. And everything seemed good. I then checked the levels that night and the day after, and everything was good. It doesn't seem like one would need to do all this work to bleed the system. At least, not in my case. But, perhaps I'm missing something.



To update you on this: I did what you just did and saw 70C on my 3rd gear log. I purchased an air bleeder and filled the system that way and 3rd gear pull (2nd 3rd gear pull, same temp) I got 60c.

I suggest reading up on bleeding the system properly.

[Bartlett]

To update you on this: I did what you just did and saw 70C on my 3rd gear log. I purchased an air bleeder and filled the system that way and 3rd gear pull (2nd 3rd gear pull, same temp) I got 60c.

I suggest reading up on bleeding the system properly.

Hmm, that's quite a difference. Yep, I'll do the vacuum method and see what happens. I'll also do 60/40 water-coolant.