If I were to get hold of an STi Air Temp Sensor, would I be able to hook this into my Apexi-PFC (on an MY00 UK).

If so, where can I get one and what models were/are they fitted to.

cheers

 

Yes.. 99~00 STi would be ideal.
I think the 97~98 STi also has them but would be inclined to get a 99~00 one to ensure it is correct.

then you just have the fun of working out which pin on the ecu is the correct one!!!!!!

Simon

 

Hmm, thought the wiring would be the easy bit. But just looked at the MY99/00 manual I have and the pin-out doesn't list the Air Temp Sensor

 

B136 Pin 19 for signal
B136 Pin 24 for ground

HTH

 

cool.. I glanced at the my00 pin out whcih didn't have it on but I know there is another pin out.. will look.

 

oops.. fiestaboy already listed it

refresh key is a wonderful thing.. if you use it.. lol

Simon

 

Do I have to use a STi Temp sensor or is it no different to a standard thermocouple.

 

Top

 

2K thermistor works for me.

Andrew...

 

cool,

do you mean connected to the Apexi-PFC input, or was that 'in general' ??

 

Where you gonna put the sensor? Intake path or Inlet manifold?

 

Tapped into STi 8 Intercooler or just before Throttle butterfly, I expect.

 

I've used it on both my Link and PowerFC.

It's just a 2K NTC bead thermistor from RS, epoxied into a piece of ali tube to add some mechanical strength, same one has been on the car for about 2 years.

If you want something that can be tapped into a TMIC, how about an OEM coolant sensor?

Andrew...

 

Cheers Andy,

I prob go the thermistor route, stick it in some tube and run a die up it to stick a thread on it.

 

This probably sounds like a daft question, but *could* you use a coolant sensor Andrew?
Reason for asking is that a coolant sensor is a solid brass unit (i think) whereas the air sensors i've been trying (to do the same thing) have all been bulb sensors within a brass housing i.e. only the sensor part measures the temperature and so the brass housing won't affect the temperature reading.
Would it not be the case that when temperature rises, the coolant sensor is fine, but when temperature drops, the coolant sensor will give an inaccurate reading because the brass takes longer to cool down?

 

TBH I don't know how a coolant sensor would behave, I have heard others suggest it and would be interested to know myself.

Andrew...

 

The air temp sensors i've tried so far Andrew have shown fairly accurate temperatures "on the way up" on the ecu. It's after you've let heatsoak into the equation i.e. 35-40 degrees+ that the problem shows itself.
When you drive off and the air temp cools down, the sensors i've tried so far have been very reluctant to come down in temperature, even after a number of miles. Strange thing though, is that if you unplug the sensor and re-connect it, the temperature drops 2-3 degrees instantly... but still too high against what the temperature really is.

 

Alan,

Did you mean Air Temp sensor or Coolant Sensor ?
What ones have you tried.

I'm thinking of getting a 2K thermistor from RS. Their only 0.83p. The £7 bead types seem to be no longer manufactured according to RS and Farnell.

 

I had an OEM coolant temp sensor to try with my Apexi. Reason i was going to use it was because it would be very easy to tap the intercooler and just screw the sensor in, plus i had a spare connector from an intake manifold loom so the installation would look fairly factory.

Can't give you any feedback as i didn't get it fitted before getting the MY06. Be interesting to know if it would work tho.

Tony.

 

I've tried a couple of air temp sensors Scott but same result on both, in that temperatures seen going up were fine, but reluctant to come down after a higher temp was seen.

 

Time to resurrect this thread. I've been thinking of various ways of measuring charge temps a little more tidily than an LCD readout with a long wire and a probe under the intercooler hose. I've thought of getting a proper charge temp gauge from SPA or Autometer - but the SPA looks naff and I don't like digital displays, the Autometer is only in fahrenheit which is totally meaningless to me. But there is an unused input on my Power FC which is for air temperature, and presumably this is to hook it up to the air temp sensor on an v4 STi (mine's a MY98 WRX).

Now, if an STi air temp sensor could be hooked up and used for example to pull the timing or something when charge temps are high, that would be great. But even if it weren't used for that, and simply used as a way to give me a charge temp display on my FC Commander, that would be great.

I'm not sure I understand the wiring for it though, having never seen one. Does it have just two connections, directly to the pins of the ECU? Does it need a separate power supply and give a separate output? Help! I'd really like to get this sorted out.

 

One pin to earth, one pin to ecu.

 

So what's the temp range of the STi sensor? And what's the range of the Power FC to read out the temp? I.e. would it only be any good as an ambient temp sensor, or would it be ok reading charge temps of say 0-100 C?

 

I use one for charge temp in my car and is fine.

 

Why didn't I think of doing this? I've been looking for a way to monitor charge temperature and I was thinking of getting a Nomad gauge but didn't want to spend the money and have the hassle of wiring it in etc.

The thing is though, the temperature sensor is pretty big (at least 10mm across) so how and where would you mount it?

 

So Alan what did you do? Just put the sensor in wherever you wanted it, ran the wires into the two pins on the ECU connector, and the FC Commander reads out the charge temps? It's seriously as simple as that? Please tell me it is!

I'm not too bothered about the size of the temp sensor - I can always find a way to mount it, it's just I don't want crappy bits of bellwire running across my engine bay with a naff looking LCD screen reading out temps. Using the FC Commander is a much better solution, if it will work out simple. TBH I've never even seen one of these STi sensors, I've no idea what they're supposed to look like.

 

Mines in the pipe before the throttle body, one wire to ecu and one wire to earth. Apexi ecu reads directly.
As mentioned earlier, i tried different sensors with limited degrees of accuracy, so thought best to use a sensor which i knew would work correctly with the Apexi.

 

So not using both wires to the ECU then, just one to a chassis earth and one wire back to the ECU? What sort of temp range have you had out of it?

 

Let me double check on the ground wire, though my previous sensor (for GEMS) was earthed onto manifold, so i'm sure i kept it the same for the Sti sensor.

Highest temp i've seen was i think 42 degrees but that was idling for 10 minutes immediately after a "hot" run.
I don't see there being any issue with using it on your car. Get a sensor and fit it. It'll work.

 

Not sure if this would be a problem, but earlier today I went out to my car and held the cars OEM air temp sensor in my hand to try and warm it. It went up OK on the Commander, but took about a minute to go from 8oC to about 20oC.

From what I've read the charge temps climb a lot faster than that when on full boost?