Hi Folks,
For any of you who look at OBDII or other data, what do you see in terms of AIT (air intake temps)? Of course it will be higher when it's hot out, and during stop and go traffic, but I am curious what people are seeing under different conditions.

I know that VF-E is proud that their SC ran IT's under 140 during track driving in 118F ambient desert temps. I got into the 130's today in 86F ambient during stop and go, and I wonder if that's a little high for me, especially considering my intake air is intercooled.

Where is the OEM sensor for AIT? Is it after the throttle body, or is it at the MAF? If at the MAF, great, since I would expect my true intake temps to be much cooler, after the intercooler.
CATTMAN

 

IAT measuring IS a part of the MAF....contact Sean@VF for a fix to that
So imagine the performance gain possibly by measuring a cooler IAT...the computer may keep some timing in it with cooler temps(but I am guessing )
All you have to do is drill and tap a hole in the IC,after it cools the air,and run a temp sensor.
It is the BU/GY wire...
The wire IS the first one on the right........



Stacy

 

do you mean IAT (Intake Air Temperature) °F or °C?? I installed Brockway R1000, great job for measuring Temps. I was running 97 degrees cruising then sitting at a draw bridge for ten minutes creeped up to 127? I did install USP intercoolers which is why I was questioning other R1000 user with stock cooler what was there IAT', hope this was helpful or what you were looking for?

 

Stacy, are you sure about the MAF also reading IATs?

They are two separate sensors on the turbo...a pair of MAFs, and a boost/IAT sensor on the Y intake pipe.

I was thinking that IATs are measured by #4.

 

NOT 100% that is where it is measured and #4 may be.......BUT on my wiring diagram that wire says 'Temp. sensor'.???
Now you have me wondering !
Come to think of it.....when I was playing around while doing a supercharger install and was checking some things....I used a heat gun on the MAF from a distance and watched that ambient air temp increase with heat on my Durametric scan program ?!

Stacy

 

I scanned through the PET part's catalog for the 997 for the word "sensor"...after eliminating all the acceleration, rain, and climate sensors, there weren't many left.

I don't know if I'm much help. I wasn't sure if the MAF read's both air flow and air temperature. It's separate on the 997TT.

- bob

 

Stacy, that's actually pretty clever!

 

Thank-you.....mind telling my wife what you said...'cause she thinks I am NOT so 'clever'....

Stacy

 

#4 in the diagram is the temp sensor for ambient temp in the engine bay, which shouldn't be the same sensor or temp as IAT.

The question now is: where is the IAT sensor located?

It looks like I may want to add 2 more custom sensors to my PLX chrono pod daisy chain: pre and post intercooler air intake temps.

Clearly more to come, but please chime in.
CATTMAN

 

Anyone have any info here?
Bueller?
CATTMAN

 

I answered it for you in that post and confirmed it today(hopefully two of us can't be wrong,LOL)........the heat gun thing did work.

AND YES the #4 in the diagram that was posted IS the under hood temp sensor that is there for turning the under hood fan on and off....

ALSO...if you are looking for what range of temps would be safe.....I am not sure that someone could answer that exactly! Ultimately you want as close to ambient air as possible.I read that a supercharger (non inter-cooled) at 8 PSI will produce charge air temps 115-200 degrees above ambient....so you REALLY want that to be as cool as possible with an inter-cooler,which you have.
You are at 44 degrees above ambient BUT remember heat soak on the inter-cooler could play into that....
What is your temp when you drive for 5 mins. at 40 mph ?
I do not think anything is wrong BUT I would check the flow of the IC pump(be sure it is flowing good) and again be sure that there are NO kinked lines.

Stacy

 

Makes sense fot turbo cars. in NA cars from what I know MAF reads temperature and naturally as MAF is before intercooler in FI hacked NA cars it makes little practical sense. GIAC ECU code probably simply approximates it to max temp they got from intercooler based on MAF reading.

 

Thanks, Stacy.
I assume that's right, and the MAF is where my OBDII is getting what it considers to be IAT. In that case, I should be fine, as my true IAT should be cooler. And if I am at just 95F IAT when cruising (not stop and go) in 91F ambient, I'm looking good.

Still I expect I will install a custom sensor to measure my true charge IAT. It'll daisy chain easily into the system I've got already for OBDII, Boost, and AFR.

Pics to come.
CATTMAN

 

I installed a SPA temp and pressure gauge on my VF-E supercharger. The temps coming out of the supercharger maxed out at 188F during two days of Porsche DE with an OAT of around 75F.
Typically the temps are in the 110-130F range when driving normally and OAT in the mid to high 80'sF.

 

And how was your car doing during that time taking air heated to 188F?
BTW 'coming out' means before intercooler of after?

Would be interesting to see data from TPC turbo system, from what they posted so far I think their temperature is coming from same MAF before compressor.