Installed LFP dual-pass heat exchanger; IAT2 not any better

[TheFleshRocket]

I've recently installed an LFP dual-pass heat exchanger (which appears to be visually identical to the Afco) on my '04, which is running a TVS Gen2 with a 2.8" upper pulley. I don't have any scientific results handy, but the IAT2 temps don't seem to be any better than with the stock heat exchanger. (Last I paid attention to it, IAT2 sat around 125F when cruising out of boost, spiked quickly to 150+ after a third-and-fourth gear pull, then quickly dropped to 135F, then slowly dropped to 125. I am kind of pulling these numbers out of my ass, so take them with a grain of salt.) I suspect that I have air in the system. During initial installation, it took a lot of messing with it to get the intercooler pump to even begin moving fluid, using the jumper method, even though I filled the reservoir slowly.

From what I've read, a heat exchanger should have the input on the bottom and the output on the top, to help force air out. The directions for the LFP HE have it plumbed opposite: reservoir -> pump -> HE top port -> HE bottom port -> intercooler -> reservoir. (I have not been able to find complete instructions for the Afco to confirm that it is identical.)

I unbolted the HE from its mounts and let the driver's side hang down (hoses are still attached to the passenger side). I jumpered the IC pump and let it run, but no extra air seemed to come out. I shut off the IC pump and shook the HE with my ear next to it, and I could hear fluid sloshing around inside of it. If the IC is properly bled and full of only coolant, I shouldn't be able to hear any sloshing, right?

Does it sound like I still have air in the IC system?

Should I swap the input and output hoses to plumb the HE "properly"?

What else can I do?

 

[Soap]

I am not surprised at all by your results. Replacing the HE will do very little for lowering IAT2's. With that being said, you absolutely should plumb the system so it flows into the lowest point and outlets the highest point. Otherwise you WILL trap air.

--Joe

 

[gt347mustang]

Old news and not surprising.

Did an experiment with this back in 07 and found the heat exchanger doesn't help with steady state temps. It does however add capacity to the system so it is beneficial to 1/4 mile racing and such.

 

[luker669]

I had the same result with the LFP heat exchanger, in fact temps were higher I think. Anyway ended up running water threw it the opposite way with the garden hose to get all air out. It helped a lot and temps did improve .


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[03cobra#694]

I only put a AFCO on mine because it looked better than the stock black one.

 

[TheFleshRocket]

I am not surprised at all by your results. Replacing the HE will do very little for lowering IAT2's. With that being said, you absolutely should plumb the system so it flows into the lowest point and outlets the highest point. Otherwise you WILL trap air.

Can I just swap the hoses as they connect to the HE? IE put the bottom hose on the top and the top hose on the bottom? (I think I should be able to do that without kinking either one.)

So.. what DOES effectively lower IAT2 temps (and isn't a significant / expensive project)?

 

[TheFleshRocket]

I had the same result with the AFP heat exchanger, in fact temps were higher I think. Anyway ended up running water threw it the opposite way with the garden hose to get all air out. It helped a lot and temps did improve .

So you connected the garden hose to the hose that goes from the intercooler into the top of the reservoir and ran water through it that way? I assume that you removed the hose from the bottom of the reservoir and let the output just pour on the ground?

 

[jrgoffin]

So.. what DOES effectively lower IAT2 temps (and isn't a significant / expensive project)?

Add the Griffin intercooler that LFP sells. With my Whipple, I can beat on it and get the IAT2 temps up to 125° or so, then they come back down real quick to around 110° (have the AFCO DP H/E also).

Not disappointed with it at all: Cooling

 

[Soap]

Can I just swap the hoses as they connect to the HE? IE put the bottom hose on the top and the top hose on the bottom? (I think I should be able to do that without kinking either one.)

Yes just swap hoses.

--Joe

 

[Soap]

So.. what DOES effectively lower IAT2 temps (and isn't a significant / expensive project)?

Nothing cheap and easy will lower temps.

--Joe

 

[TheFleshRocket]

I drained and refilled the intercooler system last night. This time, I used a funnel and gravity-fed-filled the system through the hose that goes to the intercooler, basically reverse-filling it. I left the heat exchanger unmounted, with the driver's side end hanging down at a 45-degree angle. (The front of the car was up on ramps.) I figured if coolant was going in the bottom port on the HE and it was angled like that, air should be forced out the top port.

I would add coolant as slowly as I could (without spilling from pouring too slowly) for several seconds, then stop for a few seconds. I repeated until I had coolant visible in the funnel. Then I put my finger over the return port on the reservoir (where the hose had been disconnected from) to allow myself to create vacuum, put my mouth on the reservoir fill hole, and sucked until coolant appeared in the reservoir and the coolant in the funnel had gone down. I did this several times until the reservoir was mostly full, then reconnected the return hose. Then I jumpered the intercooler pump on for about 30 seconds and added coolant as needed. I did this several times until the reservoir was topped off.

I haven't test-driven the car yet, but I am HOPING this got the intercooler bled properly. If this doesn't do it, I'm gonna see about reversing the hoses. (Upon closer inspection last night, I was a bit worried about kinking or bending them and restricting flow. I think I might need an elbow or two to allow for proper bending.)

 

[Soap]

Just plumb it correctly. Flow going into the top and out the bottom is wrong and you will end up with issues. Doesn't matter if you might have got the air out to start it will trap air eventually. Just go get some heater hose from local parts store. It's a $10 fix and will take 10 minutes of your time to do it the right way.

--Joe

 

[TheFleshRocket]

Just plumb it correctly. Flow going into the top and out the bottom is wrong and you will end up with issues. Doesn't matter if you might have got the air out to start it will trap air eventually. Just go get some heater hose from local parts store. It's a $10 fix and will take 10 minutes of your time to do it the right way.

Fair enough. I'll still run some tests as-is to see if what I did helped, but if not, I'll redo it the "right" way. (Why LFP, Afco, and others provide these to be installed the "wrong" way is beyond me.)

 

[94 Cobra R]

Kiler Chiller....

 

[luker669]

So you connected the garden hose to the hose that goes from the intercooler into the top of the reservoir and ran water through it that way? I assume that you removed the hose from the bottom of the reservoir and let the output just pour on the ground?

Yes but I just let the reservoir over flow instead of disconnecting the bottom hose.


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[cj428mach]

You are aware of the IAT2 location issues on TVS's correct?

 

[TheFleshRocket]

You are aware of the IAT2 location issues on TVS's correct?

Yes I am, and I literally just two weeks ago had my TVS modified so that the IAT2 sensor sits down in the airstream instead of recessed, just like the thread that talks about it. That seemed to help somewhat--previously when I'd start up the car after it had been sitting and heatsoaking for a while, IAT2 would be right about the same as coolant temp, and it would take a while (like 5 minutes cruising at highway speeds) to come down. Now when I start up the car after it's been sitting heatsoaked for a while, IAT2 is 20-30 degrees below coolant temp, and it drops down into the upper 120s or low 130s within a minute or two, even just cruising in town.