Hey Folks,

I was recently working with tephra on the GM IAT install in his car, and we we're coming up with some ADC values that didn't make sense. We took another look at the temperature measurement circuit and found that the applied voltage is 4.73 V instead of the 5.00 V I had assumed. As a result, the GM IAT scaling needed to be revised for this voltage. Revised scaling values are in the first post of this thread. I recommend everyone adopt this revised scaling. The temperature readings will be more accurate (and come down 2-4 deg F).

 

While that is important, the IAT data has been invaluable to me on my evo. More importantly than being accurate, being able to monitor the temp rise over time is an amazing asset to have when logging.

 

Pic of Evo X Temp Sensor - Many thanks to AMS for their assistance:

 

FYI I had a local mitsu parts guy order me one. With the gasket it came to $7

Mrfred, do you want me to send it to you when i get it to do any sort of testing?

 

Looks to be a closed element sensor. It would be interesting to compare the response speed to the GM sensor. Not sure I have the equipment to do accurate measurements though. I'll have to think about it about. I'll let you know in a day or so.

 

sounds good. I probably wont have the sensor until next week if he has to order it.

 

I had my table set like that and still managed to melt my Hondata gasket that was back there. This was the reason I decided I needed to block it off in the head, and close off the port physically.

I remember when i was trying to find the exhaust leak from when it melted, and I was almost burned by touching the intake manifold right there. It was still hot enough even with the table zeroed out that I wanted to find an alternate way to disable it.

But then again, talk to people in Charleston about me and they will tell you I am the most **** person they know.

MR Turco, you with the nail on the head, that's exactly what I meant.


Offtopic: Mychailo, did you happen to get those e-mails I sent to you of my MUT table? I don't know if my work e-mail sent them to you or not. Sometimes it does/sometimes not.

 

crap, now you have me worried that my gasket might melt

How long were you running the gasket before it melted? I have been running some spicy egts too.

 

Hmm. There must be some amount of circulation then, just not into the IM.

Yep, got your emails, but I've been working on Evo X disassem for a few days now. I'll have a look at your stuff tonight.

 

I wouldn't even bother the megasquirt guys definitely agree the open element GM sensor is the way to go from my own research. They claim the GM sensor can swing min to maximum temp in about 0.05 seconds.

The closed element sensor is going to heat soak to death on the intake manifold. I couldn't find exact readings on how slow they are but many complained about their responsiveness. I think its pretty clear that for fast acting sensors you need low mass which the open element provides.

 

I dont disagree but for $7 if mrfred can test it easily it may be worth trying out.

 

I don't know if I would be soo worried as I really tune my car to see what I can get out of it. In other words, it *might* have seen some 1600+F temperatures through the EGR hole from some of my *experimental tuning*.

Mychailo, don't worry, no kick in the butt, our IT is just starting to really look at what people are doing over e-mails, where they are going and the internet here due to a small group of bad apples. Sometimes I send out email and they never get received...

 

i may be seeing 1700 degree egts during "experimental tuning". Then again i am not sure how accurate my gauge is.

 

I second that!! Its very, very informative to be able to log the IATs especially being able to provide concrete data to show how well (or how bad in some instances) that nice and shiny new FMIC helped. I am compiling data to show which FMIC has made the most significant difference in IATs and will post it up shortly (a teaser though is that CBRD and AMS' the best so far. I've also tested an ETS, ARC and Bushur FMIC).

 

Wow, finally we're through the cold-snap here. It was -20F or COLDER all last week, highs around -2F....TO COLD to even think about doing anything, the garage never warms up, even with a heater! It was a balmy 25F here today, so I *finally* got this done! mrfred, it works perfect! I made sure to copy all of the stuff over as instructed and went for a spin, everything seemed to work as expected.



Log results from a good 3rd gear pull:


Mrfred, beer money! Send me your paypal address!