818 Intake Air Temps

[Turn In Concepts]

For those of you who have their cars up and running have you done any logs of intake air temperature? Have any of your relocated the IAT sensor to after the intercooler? I am researching a new intercooler design for this car and want to collect some data first.

Thanks
Tony

[Evan78]

I noticed that the data overlay on the recent FFR video of the red development 818 has intake air temp on it. I saw it hit 230 at the end of the straight.

https://www.youtube.com/watch?v=R-IYVWtq77c&list=UU0ssR2R6_54NRc8hT6XeP8w

[Stickshift84]

Tony, take a look at your PMs. I will gladly help you with some datalogging if I can. Also take a look at my build thread for what I have been doing to get the TMIC/AAIC to work.

[Bob_n_Cincy]

For those of you who have their cars up and running have you done any logs of intake air temperature? Have any of your relocated the IAT sensor to after the intercooler? I am researching a new intercooler design for this car and want to collect some data first.

Thanks
Tony
Tony
I have 2 sets of all the body work, aluminum ducting and a rolling chassis. If you want to stop by or I could bring it to your place to look at.
34504
Bob

[JeromeS13]

I'll have data from a relocated AMR top mount after this weekend.

[GUNS]

Tony,

Can you provide any details on what you're thinking for the IC design? It'd be nice to have an equally effective alternative to an AWIC setup.

[metalmaker12]

It's going to take a major change in the 818s to get the air to an aaic to be effective under sustained boost. Under lower boost, cooler amibient temps and driving it easy you can get by even with the current setup as Nick and I have. I drove 1000 miles with no real issues, but one autocross change that. If you wanna push it, turn the boost pass say 10-12psi and stay in boost you will melt the engine with an aaic in the 818s setup. With proper timing triming set into ecu you might be able to get by, but your power will be sucked out of the car and it won't be efficient power. 140 iat at throttle body is about as hot as you want it under normal conditions and maybe 160-170 tops under heavy load. I really doubt we can get the temps this low in the 818s with a full winshield that blocks the air coming to IC unless we make large ducts with fans to bring air to IC and ducts to vent it out with cut outs like the R. In the R it is much easier without the winshield blocking up the air flow. You can make a duct out of the passengers hump like FFR did, or build a duct or ducts to grab the proper amount of air to cooler.

Driving around not in boost, and only getting on it slightly is no fun, you wanna drive this thing like it's meant or you might as well trailer it, paperweight etc. So a full effective setup is what we need, so far Wayne's is the best solution for the 818s

[JeromeS13]

I'll have data from a relocated AMR top mount after this weekend.

Results are no bueno. I was getting IATs of 200+ with ambient temps in the mid 60's. :mad:

[metros]

Just to be clear, those temps were after the a2a intercooler?

How long into the track session did it take for the temps to get that high?

[JeromeS13]

Air to air, yes. Video for reference... (excuse the choppy video. I purchased a new Gopro and my memory card wasn't up to par)...


http://youtu.be/epSbbYAe-dY?list=UUxbdnwpfymM7uWZ9AQ2GrHg

[metalmaker12]

Results are no bueno. I was getting IATs of 200+ with ambient temps in the mid 60's. :mad:

I kinda figured this would happen even under cooler temps. I am pretty sure you realized it would prob not work with the S windshield. You simply would have to get twice the cfm of the oem setup if you want iats to get in the normal range. Above 12-16psi max you will cook the engine if you can't get the required air pressure to a top mount, or rear mount front mount a2a cooler. I would maximize your awic and work on helping reduce any potential heat soak. Iats 140-150 are usually what you want, or 40 degree above ambient is ideal. I know you saw 180 ish with your awic, so you gotta figure out why it's running so high. How do you have pump running, under boost only? Fans running all the time? Etc Do you have insulation on awic coolant tubes in engine bay, a turbo blanket and wrapped/ insulated down pipe/ exhaust . Good luck, you will get it. I will have my engine back soon, so hopefully I can help you figure out what works best.

Ps: I know you wanted to hammer it and pass those cars!!!

[Mechie3]

An AAIC can work, just not where/how FFR has it. Without any data to back me up I can think of 2 ideas that should work off the bat, and 1 that has potential.

1: Large side scoops with closed ducting to the TMIC. Not some open sided panels that are intended to magically make the air flow change 90deg 3 times. It needs to seal to the side scoop, have a large closed duct (like brake ducting) that feeds to a sealed top on the TMIC. TMIC work because of a large pressure differential.

2: Move the IC to the side scoop like Dan/RM1Sepex. Make the air blow directly on it.

3: Six star is putting their IC in the rear of the car. This has potential, but has yet to be proven.

[metalmaker12]

In the S I think awic period. Not that a2a can't be done, but it will take large amounts of effort.

In the R I think a large front mount core in the back like six star with a large center duct between the humps with ducting to core and cut out in body will absolutely work

[C.Plavan]

What gauges have a good reputation for IAT?

[sponaugle]

Indeed, Pre intercooler temps can easily be that hot, but post intercooler temps should be much much cooler.

As a reference, here is what we are really shooting for when it comes to intercoolers:

This is from my 08 STI, running and EFR7670 turbocharger at about 25psi,. I am at the very edge of the compressor map, pushing that little turbo as hard as it can go. This equates to about 500whp.

First, here is a look at a drive around with three small jumps into boost:

http://www.sponaugle.com/post/SubaruIAT1.png

You can clearly see that while the IATs pre intercooler get *very* hot (260 degrees F), IATs post intercooler don't even hit 88 degrees. Outside air temp was about 79-80 degrees.

Here is a closer look at two small jumps into boost. Similar temperature profile.

http://www.sponaugle.com/post/SubaruIAT2.png

Here are the 3 pulls at the end of a sequence of about 15 full 3rd gear pulls. This is pushing the car pretty hard. On the third pull IATs pre intercooler max out the sensor I have at 300 degrees F, but IATs after the intercooler are still in the high 80s. *THAT* is how a good intercooler should work.

http://www.sponaugle.com/post/SubaruIAT4.png

This last graph is an interesting one. This is at the end of about 15 mins of very heavy boosting.

http://www.sponaugle.com/post/SubaruIAT5.png

Temperatures pre intercooler were so hot they melted and broke the temperature sensor... IATs post intercooler peaked at 104 degrees. I did this test repeated many times with the same result. A large well designed intercooler with great airflow can work very well.. and this is an extreme case.. most people do not have pre intercooler IATs over 300 degrees.

I just added a thermocoupler to the Pre IAT side so I can measure above 300 degrees. Stay tuned for that data.

Jeff

[JeromeS13]

Jeff,

Would you mind providing more information about your AWIC that you're talking about?

Thanks!

[sponaugle]

Jeff,
Would you mind providing more information about your AWIC that you're talking about?
Thanks!

This isn't a AWIC. This is a large core FMIC. I was showing what kind of results you can expect from a good well designed intercooler setup. 200F+ degree temperature drop is possible.

I am going to run an AWIC on my 818, and I have no idea how well it work.

Jeff

[ssssly]

Long shot, but does anyone have temp plots running a AAIC with a water sprayer?

[Turn In Concepts]

A water sprayer will help, but is not a long term solution.

Tony

[metalmaker12]

Looks like I am getting my motor back soon so I can test Wayne's setup and maximizes it's efficiency. I would say over the next month to be up and running.

[grayghost]

347013470234703I am trying a different route, I have my friend the FAB MAN Tom Kaufman, open the rear deck opening to 10"y 14" and we are going to locate my Grimm Speed
air to air intercooler below the opening with a fan or fans to best keep things kool.
Note how this looks factory made, tom is amazing. Grayghost Roger

[ssssly]

Interested to see if making the opening larger will help at all. With how little air flow there is in that location I am sceptical. But eagerly awaiting results.

[Goldwing]

Any thoughts on the effectiveness, or aesthetics, of adding scoops to the top side hood air intakes? The ones beside the humps? It is at a bulged part of the body which should create a positive pressure area, adding a scoop along the lines of Mechie3's side scoops, assuming the windshield doesn't block airflow to the area. My original plan was to use the top vents for intercooler as FFR planned, the right side for engine air intake, the left for general engine bay venting. Maybe swapping the general venting and intercooler air will be in order, but just floating the top scoop idea to see what you guys think to help the FFR system.

[Goldwing]

The middle rear trunk vent looks to be a low pressure area making me think FFR was using an aerodynamic pressure differential to vent the intercooler.

[sponaugle]

I just added a thermocouple to the Pre IAT side so I can measure above 300 degrees. Stay tuned for that data.
Jeff

As promised, I added a thermocouple to the Pre IAT side. It is an Omega Exposed Tip K-Type thermocouple connected to an AD8495 based thermocouple-to-linear-0-5v adapter (http://www.adafruit.com/products/1778).

http://www.sponaugle.com/post/SubaruIAT6.png

In the first graph you can clearly see the response time of the thermocouple as compared to the GM IAT sensor. Not only is the peak temperature higher with the GM sensor, but the falloff in temperature is much slower. I believe the thermocouple represents a more accurate view of the temperature of the air. The GM sensor is much more prone to heat soak.

http://www.sponaugle.com/post/SubaruIAT7.png

In the second graph you can see how the GM AIT sensor is maxed out at 300 degrees F. The sensor itself can read a bit higher, but it is not intended to be exposed to these kind of temperatures and have a long life. My particular software calibration doesn't go any higher. The thermocouple is more robust both in construction as well as temperature range. Since this is a K-type thermocouple that is rated to 1200 F, I will certainly not have a problem.

Having seen how well it works, I am going to switch both my pre and post IAT sensors to thermocouples.

Jeff

[C.Plavan]

If you are seeing over 300 degrees at AIT, then you have other problems.... :) Plus, you are starting at an already too hot of temperature on the test (150 degree). I would like to see an ambient to 150 degree chart.

I'm installing a GM unit in my AWIC. If it fails, you can run to an autopart store and grab one.

[sponaugle]

If you are seeing over 300 degrees at AIT, then you have other problems.... :) Plus, you are starting at an already too hot of temperature on the test (150 degree). I would like to see an ambient to 150 degree chart.
I'm installing a GM unit in my AWIC. If it fails, you can run to an autopart store and grab one.

No doubt this is a great example of an overdriven turbocharger. In the first graph you can see the starting temp is just a bit above 100 degrees Pre-intercooler. Remember both of these graphs are PRE INTERCOOLER. The previous posts shows the pre and post intercooler data, which clearly shows how well this intercooler setup works. With outside ambient temps of 75-80 degrees PRE intercooler temperatures don't drop much below 100 degrees, so that first graph is actually very representative. Pre intercooler temps actually get even hotter if you sit at idle for a while.

This second post was just to illustrate the difference in response of the thermocouple as compared to the NTC thermistor.

Here is that first graph with the POST intercooler IATs added:

http://www.sponaugle.com/post/SubaruIAT8.png

Jeff

[Bob_n_Cincy]

Jeff
Is this what your using for a sensor?
http://www.omega.com/googlebase/product.html?pn=TC-K-NPT-E-72&gclid=Cj0KEQjwiJiiBRDh3Z-ctPfS5MgBEiQAAlkbQgue_YMuFt6Y5w9tSR8Wz0insw1npkKeo d3QnvENW6QaAkIS8P8HAQ
Bob

[sponaugle]

Correct. 1/8 NPT exposed tip version of that sensor, plus the thermocouple to 0-5V from Adafruit.

http://www.adafruit.com/images/970x728/1778-00.jpg

[metalmaker12]

The middle rear trunk vent looks to be a low pressure area making me think FFR was using an aerodynamic pressure differential to vent the intercooler.

Simply put, an A2a won't work on the S unless major mods are done.