Chowcow

Hi All,

I'm having quite a bit of trouble finding out an exact answer for my problem. I am planning to turbo the car in a couple of months but decided to work on understanding MS first and getting the NA stuff worked out before I boost. That being said, I'll be installing a few things in the upcoming weeks. The MS3, RX-8 injectors (yellow) and wideband.

My question that I can't quite come to an answer for is whether I can re-use the stock IAT on my NB2. I was just about to pull the trigger and buy the GM IAT but had the parts guy point out that I have a stock IAT on my cold air intake that's separate from the MAF (See picture). Call me an idiot, but I thought the IAT was part of the MAF, which would be useless once MS3 was installed.



Anyways, my question is whether I can just plug in my MS3, find the IAT wires and re-run them to the MS3. Would that be a sufficient IAT reading to have the ECU work? Where would I find the calibration for the stock IAT for the MS3?

Thanks in advanced

http://imgur.com/t58B8Oo

pdexta

iTrader: (17)

As far as "can it be done" I can't give much advise, I'd assume you could do it but it's over my head.

As far as the GM IAT, it's like $20 and it's what EVERYONE uses. It's the default on every miata basemap I've seen, it's plug and play, simple to install, accurate, reliable, cheap, and it fits into the most common, airtight, sensor bung there is (If I remember right yours just pushes in and will blow out the second it sees boost?).

You could always try to reinvent the proverbial wheel, but the one we have works damn well. If you're looking to blaze new paths to innovation I think there are much better places to start than the already perfect solution everyone else uses. My $.02 anyway.

Chowcow

I went to my local tuner shop to pick up the GM IAT and they wanted $60 for it (Canada). Ordering it from the states and shipping it here alone will cost me more than that. I'd rather just order the turbo kit with it on and have it all ship together.

The reason I want to use the stock IAT is because even if I get the GM IAT, I have nowhere to install it (see picture). The current IAT sits inside the CAI with rubber fittings, I believe it just pulls right out. It's definitely smaller than the GM 3/8" NPT.

Drilling a bung into the aluminum isn't an option as I'd like to resell the CAI when I'm done with it. Again, I'm trying to get the IAT run with the MS3 while I'm still NA so I can figure out tuning before boosting.

Braineack

iTrader: (62)

how is it held into your crossover tube?

Chowcow

By crossover tube I'm assuming you just mean the aluminum piping? It's just a rubber O-ring that fits the stock IAT snug.

Braineack

iTrader: (62)

now how do you expect that to hold under boost?

DNMakinson

iTrader: (3)

Stock sensor is encased in plastic and will respond slower than the GM open sensor.

Chowcow

I'm trying to run the sensor while the car is naturally aspirated. Once I have an idea of how the MS3 works, I'll be ordering the no ECU FM2 kit - which includes a bung near the throttle body.

So for now, the question is, how do I use that IAT sensor for the MS3 and If I can't, where can I mount the GM sensor with the current engine layout?

Chowcow

But will I be able to plug in my MS3 into the current harness and have it draw from that sensor without any problems? If not, where can I find the calibration numbers for this sensor?

18psi

iTrader: (76)

You need to do better research, because this has been discussed before.

Basically the answer is YES you can use the stocker while n/a, nothing special required just use the oem calibration. And YES you can later use the GM, and YES it will wire right up to the oem ait harness, polarity doesn't matter, and yes it will work just fine, and all you gotta do is use the GM sensor calibration

Braineack

iTrader: (62)

you guys didnt let me draw this out for days.

Chowcow

Thanks for the answer. I'll search for the OEM calibrations now.

18psi

iTrader: (76)

They should be loaded in MS3, at least the base ones that should be really close

you just have to use the rx7 s4 calibration or soemthig for the stock one, and the gm one for the gm one....

Chowcow

Ok, one last question then. Is there even a need to rewire the stock IAT into the MS3? I'm assuming if the MS3 plugs right into the stock harness, and the stock IAT is part of the harness, it should all be gravy. Unless I'm missing something here..

BTW, this link here has all the calibration values incase others are running into the same problem.

DIYPNP MegaSquirt installation for the Mazda Miata

18psi

iTrader: (76)

you're overthinking things hahaha.

no need to rewire anything. you're all set. connect the 2 wires from ait to the 2 wires from stock ait harness and you're done.

ez pz

Chowcow

Thanks again! Although the stock AIT should already be connected to the stock AIT harness -- I'm sure this will make more sense to me as I do the install. At the moment I'm just blue printing my procedures. I'll probably do a build thread once I get started.