air sensor relocation. . . worth it?
 

i was wondering. . . has anybody noticed a REAL difference when relocating the stock sensor? what i mean is. . . has anybody recorded that there IS a difference when relocating it. if i relocate mine ill do it like david garfinkles is done. he used one of the additional injector bungs that was already on his greddy elbow. he pressed nylon into it so that it wouldnt heat soak. makes sense to me, but does it REALLY matter?

paul

Damn I guess that would be a better way, I was going to say I could make you a small threaded bung like I made for my IC pipe.
But it would make even more sense to isolate it from the aluminum altogether.
I don’t know how you would make a simple isolated bung out of nylon that wouldn’t look ghetto or leak though?

Re: air sensor relocation. . . worth it?
 

Paul,

I put an aftermarket sensor on my car under the intake elbow where the elblow meets my SMIC. Its underneath it in my PLASTIC elbow. The result is nearly identical #'s to the stock sensor. Turn the car off and wait an hour the #'s are nearly identical to what the power FC displays for the stock sensor (when adjust F to C).

The engine itself is heatsoaked so any sensor you use will be too, atleast thats my result.

I think it has more to do with reaction time. Under the UIM the thing is in a very large hunk of aluminum and is picking up radiant heat as well. Relocated to a IC pipe it reacts faster and is more accurate to the actual temps seen inside the manifold.

Well... the stock sensor and the stock sensor location is already calibrated into the ECU, after countless hours spent by Mazda. Probably counting in the heat soaking, the radiant heat and so on. By relocating it, you will probably need to have it recalibrated, re adjusting the enrichment values and etc...

Yeah, and there was that guy at Mazda who spend countless hours deciding that the side vents didn't have to be functional, getting heat out of the engine bay.

Or the guy who spent countless hours deciding we needed a precat, to bake our vacuum lines.

Or the guy who spent countless hours deciding that plastic was an acceptable material for the AST.

The side vents are functional, they vent the heat from the oil coolers.

That was due to the US passing increasingly strict emissions laws, Mazda needed a pre-cat or the car wouldn't have even been sold here.

I would put that down to either weight savings or the bean counters. Who will ever know, now?

As much as we all bitch about some of the decisions Mazda made, the engineering of this car is simply amazing.

I don't really see the benefits of this unless you spend tons of time in traffic jams... and I daily drive my car and hardly ever get stuck in traffic jams :).

The main hazard I see with the intake thermo sensor heat soaking is that the ecu thinks that there is less oxygen coming in because hot air is less dense and contains less O2. So if the air coming in is actually cooler than what the ecu thinks, you will be running lean (assuming that the ecu is not fully compensating for it). However, I have never heard of someone detonating and blowing an engine because the thermo sensor has heat soaked (correct me if I'm wrong here). So the lean condition that arises from this must be pretty much negligible.

Now my point... The main reason to relocate the sensor is so you the car will get an accurate reading of the air temps without the heat soak factor and the "lower" intake temps will help make more power (just like when you drive in colder weather). IMO, the car is combusting the same temperature of air regardless of what the thermo sensor says. Your not going to make any more power from the lower temp reading on the sensor (assuming its 5 deg Cel or so). If anything, you may be running slightly richer since you will not be getting the small lean condition described above. If the air coming in is hot, you'll make less power and vise-versa. So I don't believe that just b/c the sensor is reading lower temps, the car is going to make more power. As far as having the sensor recover from sitting in 90 deg F traffic jam, well that makes sense, but how often does that really happen? You drive the car easy for 5 or 10 minutes and let her cool down and your set.

Agreeing with rynberg, the engineering of this car is truly incredible. They put the sensor there for a reason, and without lots of data to fuel the need to move it, I don't see why one would.

see. . . this is my concern. is it worth it? cause with my fmic. . . i see temps DROP when i start moving. then does it matter? it does matter a little bit. . . if the sensor reads a different temp than what is actually there. . . it will go into adding/subtracting fuel/timing and whatnot. . . it wont drive the same. ive noticed this when a sensor is bad and reads the wrong temps. . . how do i know this??? theres no way that on an 89 deg F i will see 28 deg C intake temps. . . in city traffic. haha.

ill probably just move it. . . hell. . . itll be something to do. hahahahaha.

paul

I beg to differ on this.

I have a 94 R2, and after getting intimately involved with that area of the car during a CWR oil cooler upgrade, they do not. Unless the path of the air is up over and around the fender liner.

And that cooling is of nowhere near enough use as venting the back of the engine bay. They were originally designed to be for the engine bay (so I have heard), but that was changed. That was a wrong move.

Yes that is exactly the air flow of the stock car.

if you pull off the liner you can see the ducting in it.

ast is plastic because everything else in everyother cooling system mazda makes from about 89 on is plastic

And I thought this was the Advanced Tech Section, lol.

Mazda did not have a brainchild locating the IAT under the mani, it was a packaging solution not an engineering solution. So obvious, how can folks dispute this? About as good as their election of sensor as many other OE IATs are faster. Look at other Mazda 2-rotor turbos and you'll find the IAT in the elbow! Wow, they screwed that up I guess!

The only reason that Rx7s do not blow up all the time ... wait, they do blow up all the time.

Just add the above poor design to the plastic tick tick ticking time bomb called an AST, an ECU with an non-functional knock sensor, crap solenoids that give up their nipples like a drunk college student, crap underhood hoses especially on the 93s, an IC duct so small that it can't provide enough air for the motor let alone the IC, why go on?

Relocate the sensor now, put it in your front mount outlet if you got one. Seriously, move it if you want, move it if you beleive it will help. The net effect is beneficial but not major (due to the piss-poor sensor selection).

You may think that but its not true. I have an aftermarket intake sensor located in the plastic elbow where it meets the cuppler (across from the alternator). The sensor displays nearly identical numbers (converting F to C) as the stock sensor. When I move they both react about the same time. They are within a couple degrees of each other. Most of the time its nearly exact.

I relocated mine to the elbow (had to for the Cosmo intake manifold) and saw no change whatsoever.

I need to change my a AIT soon...my original one is currently malfunctioning...does anybody have a different one (GM) than the stocker on there FD. And can you tell us if it has a better reaction time.

If it does make a difference, the part# would be great...I have a buddy that works at a GM dealership and gets me like 30% off...if anybody needs one let me know. I'll buy a bunch at once and pass on the savings.

Crap...sorry I didn't read this first. So, according to your testimony, the aftermarket AIT has nearly identical reaction time as the stock one. Interesting.

Oh yeah, I forgot the genius design in the FPD, and line from the AST to the overflow tank that is 3 pieces, with plastic connectors.

Mind you, I'm not debating the overall genius of the car, just certain issues.