Frankyy

I am trying to find some information on where the IAT sensor is wired into the ECU, map is basic plug in, but i searched and searched did not find any info for the IAT wires,

1 wire is red, the other is brown

it's a 92 s13 SR redtop number 62

Frankyy

I have pictures , they are in japanese, but I am not certain it is corect, there is no numbers or no colors..

Z U L8R

cut the wire on pin 26 of the ecu and run the red wire of the iat to the ecu side of the wire, so it goes right to the ecu

tap the brown of the iat into pin 21 of the ecu

mount the iat IN the intake plenum NOT in the intercooler pipe. i'd recommend taking off the upper intake manifold and tapping into it. you'll need a 10mm x 1.25 tap and the appropriate drill bit, i don't remember it off the top of my head.

best place on the stock s13 manifold i've found is right behind the throttle body on the bottom side of the intake plenum.

you could A. move the throttle body, take off the alternator, and be very careful about drilling and tapping not to get any aluminum shavings in the intake. before you get started you can stuff a rag behind where you'll be working since the throttle body is out of your way, then once you're done pull the rag and shavings all toward you......but....

better not to chance it at all and just do it the right way. which is removing the plenum all together and that ensures no metal in the motor. it's just a little more effort but it's worth the piece of mind. a 12mm swivel socket + locking extension = your friend.

i'd recommend putting some grey permatex (RTV) on the threads and bottom side of the sensor, then screwing into your tapped hole, however do not overtighten it. thread sealant/teflon tape will not seal it because it does not seal from the threads, it's a machine thread not a pipe thread. that's why i use RTV.

grey and black rtv are o2 sensor safe, grey withstands the highest temp which is what i use on just about EVERYTHING (oil pan, timing cover, t-stat, water pump, valve cover, etc) , unless it's in the exhaust then i'll use permatex copper.

i'll spray headgaskets, metal gaskets, and paper gaskets with copper spray.

i like grey the best because it's subtle. black kinda stands out, and i HATE seeing orange ANYWHERE LOL. the factory nissan is either black or orange when it comes with your master gasket kits and what not, but i still use grey for everything....it's OG

hope that helps,

Dave

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RB25 280z GT30/76R 441hp/381tq [email protected]

jspaeth

I made this thread:

http://zilvia.net/f/tech-talk/170290...-pictures.html

But that is for a late-model blacktop SR

....the original ECU was a J4 ECU (out of 1996-1999 180sx Type-X).

The pinout for your redtop could possibly be different.

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Daily driven

jspaeth

Dave, why do you say this?

Quite a few people with reliable/high hp setups are running it in the coldpipe pre-TB with no problems at all.

Wondering why you are anti-this.

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army240

X2, I wanna know why too!

Hummm and as we're talking about IAT...

Water/Methanol injection kit nozzle... where would you mount it? Before, or after the IAT?

I have some doubt that water and alcool isn't that safe for IATs... but it would cool of the air as it get in, and it would be better if the IAT would sees that temp change... so i'm a bit torn between those ideas...

Anyway,

Thanks guys!

Frank

slider2828

I agree too.... I have mine in my IC piping... Its just a intake air temp... not too big of a deal.... I assume....

I would say water method behind the IAT

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jspaeth

If I understand how water/methanol are intended to work, it really has nothing to do with IAT.


The water/methanol (I believe) is there to provide cooling DURING the comubstion process.

Injecting it into slightly hotter than ambient air in the cold pipe would not do anything significant to the temperature of that air.

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army240

When I stand in front of my humidificator in my house, I can feel coolness. The water is almost at the same temp. than the ambiant air... so I don't know, maybe it would cool the intake air as well(which there is a pretty big difference in temp.)

But seriously, I really don't know, all inputs from everybody are appreciated

Thank you!

Frank

jspaeth

That's just not really true.

A good intercooler should be able to cool the turbocharged air down significantly.

Injecting a mist of ambient temperature water/meth into air that is slightly hotter just is not going to have much of an effect.

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army240

Just took a look at my Log files from some Drag... you are right, Intake temp is about ambient air, my bad!

So I guess you are right, the temp change wouldn't be that big... I risk more to damage the IAT shooting a mist of water/methanol on it

Thanks a lot

Frank

Z U L8R

i prefer the intake air temp sensor in the intake manifold because , if your intake manifold heat soaks from the heat of the head it's bolted to, that will raise the air temps in the intake manifold but not necessarily the intercooler pipe that's separated by a couple on the cold pipe. rb stock intake manifold frickin sux since it's directly above the valve cover...hot air rises....

basically it's a more accurate reading of what the motor's actually ingesting by being in the intake manifold.

obviously you can do it in the intercooler piping, or hell you can do it in the intake snorkel like a lot of factory cars are when they're not built into the maf. but since we're performance oriented, if you can get the most accurate readings possible from ANY sensor, why not?

yes it's a bigger pain in the ass to take off the intake mani than just weld a bung in the intercooler pipe, but it's worth it to me and my customers to go that extra step.

if you've already got it in your intercooler pipe, your car's tuned for it that way, and it's running fine, i'm not saying ZOMG YOU'RE AN IDIOT CHANGE IT NOW! i'm just answering the question of why I do it in the intake manifold and my reasons/thoughts behind that. on an rb26 the iat is on the end of the plenum kinda where the throttle body would be on a rb25 greddy intake manifold. but since it's before the itb's that could technically be classified as "cold pipe" as well. so i'm not condemning anyone for doing it differently or anything like that.

hope that makes sense, and you don't have to defend yourself to me, explain to me, or justify why you put it in the cold pipe. it's all good lol

as far as your water/meth goes, i'd install the fogger in the cold pipe with some space but try to get it before the pipe bends to go down through the fender. i'd try to get it in the straight section as far out as i could and i'd have the iat in the intake manifold where i mentioned.

that's how i'd roll unless there's a better suggestion with a logical explanation.

hope that helps,

Dave

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RB25 280z GT30/76R 441hp/381tq [email protected]

jspaeth

Dave, the key is what you said....that the IAT stays in the location where it was when the car was tuned.


Honestly though, I don't think the temperature of the manifold itself will affect the temp of the charged air...

1) If you touch your intake manifold, it is never very hot

2) The air is moving so fast at that point that it physically is not in contact with the metal in the manifold long enough to heat up very much.


That's just my engineering guess, but I could be wrong.


Actually....now that I remember it, I have heard that the heat from the manifold can actually heat up the ENTIRE sensor.....moreso than the coldpipe, which is substanitally cooler.....

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Z U L8R

you'd be surprised actually. the water acts as a conductor and with the air moving across the water it can definately wick away a lot of heat.

simply spraying water on your intercooler doesn't really do anything, but spraying water on your intercooler while you're moving and air is blowing on it does.

one of the ways you can diagnose a bad/restricted ac condensor if the pressures are good is by spraying water on it and putting a fan in front of it, then reading the temperatures of the ac lines. if it improves the efficiency of the system then you can know replacing the condensor as part of that ac job will definitely yeild improvement. this is obviously an isolated test done for a specific reason, but i'm just explaining the principle of spraying water on something with incoming air will definitely dissipate heat more efficiently than just moving air alone.

it's the same effect as running through a sprinkler on a hot summer day. if you just stand in the sprinkler you'll be cooled off a little, but if you get wet from the sprinkler then run in front of a fan, you get cool even better/faster.

same priniciple

gl,

Dave

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RB25 280z GT30/76R 441hp/381tq [email protected]

jspaeth

I gotcha Dave.....I am in chemical engineering, now doing my PhD (ugh been in college for 8 years!!!!), so I know my heat transfer haha

Good analogy!!

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Z U L8R

1. i agree

2. i disagree, the temp difference does change the density of the charge, hence why they make phenolic (sp) intake manifold gaskets, and why people delete the coolant passages that run to the throttle body, etc.

3. i disagree, drive your car around till it gets to operating temperature, do three WOT pulls and pull over. lay your wrist on the intake manifold and hold it there for 10 seconds...if you can :P

4. i disagree. ever wonder why your car runs richer when it's colder? when your motor's cold, the intake manifold and intake valves are cold. therefore without that heat it's not able to atomize the fuel and combust it as efficiently as when the motor's at operating temperature. therefore in order for it to maintain a stoich a/f ratio it must dump more fuel to get the that same stoich a/f ratio at that operating temperature...and that's at idle. more fuel is also added to generate more heat, therefore the motor can reach operating temp faster, as well as why your idle is higher.

the temperature of your intake manifold affects wall film, and wall film also contributes with the injector pulsewidth to give you your total air/fuel ratio.

5. i disagree, now you're contradicting yourself in what you said in 3. but also these denso aka mazda rx7 intake air temp sensors that apexi uses are in the intake plenum of the twin turbo 13bt's....and rotaries DEFINITELY run waaaay hotter than a piston motor.

plz don't take this the wrong way because i'm totally not trying to pick on you man. i just disagree and wanted to explain why so you can understand my logic.

love you long time,

Dave

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RB25 280z GT30/76R 441hp/381tq [email protected]

jspaeth

Not a problem, the points you made are all valid, and you have swayed my opinion on some of them I think......

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Frankyy

thanks alot Dave, Even before posting this thread I had already installed my sensor, I was told to put the IAT as close to the TB as possibly still mounting it in the IC piping because the intake has ruined IAT sensors before. Just taking words of advise from someone more knowledged then me, Dave also prooves strong opinions

so I got my answer basicly

cut wire on pin 26 conect to red wire
Tap into pin 21 conect brown wire

Thanks again Dave!