i just finish the relocation of the air temp sencer today. It seens to work very well.
i place the sencer in the intercooler pipe. (will post picture later tonight)

after the relocation the air temp drop about 15-20c while drive in the same weater condition.

no more ruff idle after park
city driving will get up to about 40c (with cold air intake) before it gets up to 55-58
but drop down once the car is moving. (drop back to 30-34)

but one thing is that the car seens to run leaner ! ~~ anyone relocated the sencer have this problem ?

but over all i m very happy with it. feel the car runs more smooth. quicker respond.

just trying to share my opinions so please dont fire at me if i m not right...

thank you.

 

Cool!! I was contemplating doing this same mod. Those are interesting temp figures.

R.K.

 

No One Els Want To Shared Their Result After This Mod ?

Come On Guys... Post Something It Will Benefit All People Who Owns An

Rx7 !!!!

 

It's odd that it seems to be running leaner, I would have thought it would run richer?? The reason I say that is because when I drive my car early in the morning and the air temp is low, it runs alot richer, to the point where I have IDC's around 5-10% higher than normal daytime driving.

 

This has been done by many but they usually run the Apexi PFC ECU. There are a few AIR TEMP vs ?? tables that can be modified with the PFC.

For safety sakes, Mazda has the values in the AIR TEMP vs INJECTOR table set very rich for normal and higher temperaures so it leans out as the temps get cooler. The air temps are really the same but you sensor is now in a cooler location where it no longer heat soaks so badly, thus it is leaning out. This table is not linear because of the original location of the sensor and the pitafully small IC that Mazda used.

With large ICs and relocated air temp sensors, we single turbo/PFC guys change a few of the tables affected by air temperature. I run a linear AT vs INJ table for 50C to 10C and then go rich beyound both end points for safety.


The attachment shows my sensor on the oulet of my FMIC before going single turbo.

 

Correction to "There are a few AIR TEMP vs ?? tables that can be modified with the PFC. ". Need the DATALOGIT to change the tables.

 

It would be more typical to see it run richer as this is the pourpose of moving it. When the UIM heat soaks the engine can get colder air than the sensor is actually reading and then you get a sensor that's adjusted or what it see's as hotter air (and leans the fuel) when it's actually getting a cooler denser amout of air with a leaner fuel demand. I'm only guessing he placed it after the inter cooler and before the throttle body elbow. But I would have expected the opposite of what he got.

 

OK I get the heat soaking problem but don't you think that the air is re-heated from there? My FMIC is always rather cool the pipes under the hood can't be touched with getting burned. Are there not better air temp units out there that don't get heat soaked as bad?

 

correct me if i m wrong, so what you mean is that hotter air get less fuel ?

with my understanding hotter air gets more fuel. and i think that is you i think i m running leaner.

 

AIR...............MAZDA Stock....Kevin's true......Mine
TEMP...........values..............by air density...based on testing
************************************************** *************
70C/158F.......0.957...........0.930.................1 .000 richer for safety
50C/122F.......0.984...........0.969.................0 .969 linear
30C/86F.........1.012...........1.031................. 1.031 linear
10C/50F..........1.055...........1.105................ .1.096 linear
-10C/14F.........1.102...........1.191................. 1.242 richer for safety
-30C/-22F........1.148...........1.289.................1 .345 richer for safety

For 50C drop to 30C is an increase of 2.8% fuel by the stock map.
For the linear map it should be a 6.2% increase.

 

I may be wrong as I'm working from a stock rechipped ECU but when the motor reaches operating temperature the ECU leans the motor out, so hotter = less fuel, when the car measures the warm air in the UIM it doesn't react right away (don't know the exact amout of time it takes to adjust) that's why when the engine bay is hot and you then begin moving through cooler air what the temp sensor see's in't what it's getting and this is generally why people po there motors on the stock configuration (ECU) with mods so hopefully by moving the temp sensor to a place that will see the cooler air sooner is supposed to help give a truer reading of what it's getting. SO a heat soaked motor has been leaned out, put cold air in it and it won't have the fuel it needs to prevent detonation (again my understanding)

 

FWIW, I'm still on a stock ECU and I loved how my car ran this summer after relocating the IAT to the intake elbow. I live in the midwest, and now that it's cooled off, my car runs rich for too long. This is marginally OK with me, as the car goes into storage anyway. But this spring I'll probably have the same problem. I'll have to keep an eye on fuel dilution and spark plug condition.
In short....On a stock ECU I like it in the hot weather. Not so good when it's cool (<60 F. ).