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You can export the data from Logworks as a tab-delimited text file (on a per session basis). It's pretty easy to get it into Excel from there...

BTW, I'm assuming that IAT is the intake air temperature before the supercharger... I guess charge temperature downstream from the intercooler is not available as an OBD-II parameter?


TC4_2 is ambient for air temps flowing thru the IC core. But can also assume air temps pre air intake are similar.

Air Intake -> SC -> IC -> Engine
So
TC4_3 is just before IC
IAT is just after IC which goes straight to intake manifold...
Both post SC temps.
 

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Discussion Starter · #143 · (Edited)
Call me a tart but I looked at that PDF and it seems to only describe the thermistor part (two leads) but there are four leads going into the housing of the IAT (Bosch part# 0 261 230 042). I would take my multimeter to it but there's no good access to the leads because of the environmental seals - can you simply tell me which colors are what? Or simply which lead provides the variable voltage from the thermistor? Also what's the most convenient source of +12v (ignition on) to tell the fan controller when the ignition/engine's on and off - my guess is that one of the leads going into the IAT is +12V? - TIA - john.

here's the image from my engine:

From the '08 MY schematic:

You're looking at the TMAP Sensor...
Yellow (Y) is ground
Brown/Green (NG) is the temp signal
Slate (S) is MAP +5V
Orange/Green (OG) is MAP signal

TC4_2 is ambient for air temps flowing thru the IC core. But can also assume air temps pre air intake are similar.

Air Intake -> SC -> IC -> Engine
So
TC4_3 is just before IC
IAT is just after IC which goes straight to intake manifold...
Both post SC temps.
If I'm reading the schematic correctly, IAT is taken from the TMAF sensor, which would put it pre-SC. The temperature signal from the TMAP sensor (post-IC) is not used...
 

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If I'm reading the schematic correctly, IAT is taken from the TMAF sensor, which would put it pre-SC. The temperature signal from the TMAP sensor (post-IC) is not used...
first off, I am just learning by seat of the pants so excuse me if the following is totally off. TMAF= temperature mass air flow?


If what you've pointed out is true:

1) why would TMAF have high correlation with RPM/Load etc? as you say the location is pre - SC.
2) How can this temperature be consistantly higher than that of the post SC/pre IC temps?

Searched around found this link. Pinout 18 TMAF - IAT ground and 31 TMAF - MAF ground. May be there are 2...

http://www.lotustalk.com/forums/f25/forcedfed-dyno-plot-9232/index4.html
 

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Discussion Starter · #145 ·
first off, I am just learning by seat of the pants so excuse me if the following is totally off. TMAF= temperature mass air flow?


If what you've pointed out is true:

1) why would TMAF have high correlation with RPM/Load etc? as you say the location is pre - SC.
2) How can this temperature be consistantly higher than that of the post SC/pre IC temps?

Searched around found this link. Pinout 18 TMAF - IAT ground and 31 TMAF - MAF ground. May be there are 2...

http://www.lotustalk.com/forums/f25/forcedfed-dyno-plot-9232/index4.html
I don't have a definitive answer, but I'm leaning towards IAT being pre-SC. Maybe an engine expert can chime in (paging charliex...). Even though there's some correlation, it seems that changes in IAT are related to engine temperature (which is correlated to RPM/Load also) and not charge temperature. I don't see IAT being higher than the post SC/pre IC data in the graph below (from your session3). There's been some discussion of how the throttle body gets heated by some of the emissions gear, which can cause IAT to rise higher than ambient, and be related to engine load.

The pinouts you're referring to are just two pins from the TMAF... and yes, TMAF stands for Temperature/Mass Air Flow sensor (it senses both).
 

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Discussion Starter · #146 ·
I don't have a definitive answer, but I'm leaning towards IAT being pre-SC. Maybe an engine expert can chime in (paging charliex...). Even though there's some correlation, it seems that changes in IAT are related to engine temperature (which is correlated to RPM/Load also) and not charge temperature. I don't see IAT being higher than the post SC/pre IC data in the graph below (from your session3). There's been some discussion of how the throttle body gets heated by some of the emissions gear, which can cause IAT to rise higher than ambient, and be related to engine load.

The pinouts you're referring to are just two pins from the TMAF... and yes, TMAF stands for Temperature/Mass Air Flow sensor (it senses both).
Just to add a little support to this... here's the graph of downstream cooling air vs. speed that I logged... note that there are 10-15 degreeF (6-8 degreeC) increases in the cooling air during high load periods... I'd expect to see some of that in the IAT if it was post IC...

 

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I don't have a definitive answer, but I'm leaning towards IAT being pre-SC. Maybe an engine expert can chime in (paging charliex...). Even though there's some correlation, it seems that changes in IAT are related to engine temperature (which is correlated to RPM/Load also) and not charge temperature. I don't see IAT being higher than the post SC/pre IC data in the graph below (from your session3). There's been some discussion of how the throttle body gets heated by some of the emissions gear, which can cause IAT to rise higher than ambient, and be related to engine load.

The pinouts you're referring to are just two pins from the TMAF... and yes, TMAF stands for Temperature/Mass Air Flow sensor (it senses both).
yes the cylinder head gases are routed to the throttle body location. But these temps must be in the 100C's. (more reason to install a vent to atmosphere oil catch tank)

The MAF is before the TB, on the airbox, so is that to say the TMAF is not located behind the throttle body then? If not, then this temp sensor should be getting hit with only ambient air. I'd think the ecu would want to take IAT temp post SC because this is the charge right before combustion, so seems counterintuitive. hmmm...

on your graph, whats the yellow temp? if it's downstream and it's not the "TMAP IAT" location on the exit side of IC, did you put a probe here?

nice job on plotting the graph, thanks for doing that.

Oh... note checked multiple times with an infrared gun pointed at IAT location (at idle), and it matches the IAT reading. But this could just be a coincidence.
 

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Discussion Starter · #148 ·
yes the cylinder head gases are routed to the throttle body location. But these temps must be in the 100C's. (more reason to install a vent to atmosphere oil catch tank)
Yes, and I think some of that heat soaks the area around the throttle body, perhaps even the airbox (making it an interheater, I guess).

The MAF is before the TB, on the airbox, so is that to say the TMAF is not located behind the throttle body then? If not, then this temp sensor should be getting hit with only ambient air. I'd think the ecu would want to take IAT temp post SC because this is the charge right before combustion, so seems counterintuitive. hmmm...
I would have thought that it would be useful to measure the temp of the charge after the IC too. :shrug: Maybe it has something to do with the evolution of the ECU; the N/A version of the car only needs the temp and flow from the TMAF at the airbox.

on your graph, whats the yellow temp? if it's downstream and it's not the "TMAP IAT" location on the exit side of IC, did you put a probe here?
The yellow temp is cooling air from the roof duct after it's passed through the IC. The sensor I used to measure cooling air flow through the IC has a thermocouple and pressure sensor too, so I was able to take all that data at the same time.

nice job on plotting the graph, thanks for doing that.
You're welcome, and thanks for the data :D

Oh... note checked multiple times with an infrared gun pointed at IAT location (at idle), and it matches the IAT reading. But this could just be a coincidence.
Yes, at idle the SC is bypassed, so the air coming in from the airbox is not compressed, and should be roughly the same temp post IC.
 

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Yes, and I think some of that heat soaks the area around the throttle body, perhaps even the airbox (making it an interheater, I guess).
but the MAF is really really "far" away from the TB and the fact between it is the rubber inlet and abs plastic on the box that act like heat gaskets. just find it hard to believe air rushing downstream would still yield such high heat soak. Also when i was monitoring the IAT, the temps moved really quick up and down, quicker than I guess heatsoak can. The TC4_3 IC inlet temps behaved more like a heatsoaked location would.


I would have thought that it would be useful to measure the temp of the charge after the IC too. :shrug: Maybe it has something to do with the evolution of the ECU; the N/A version of the car only needs the temp and flow from the TMAF at the airbox.
but that's cos that's the intake charge temp that goes direct to the intake manifold... as opposed to SC. I mean on an NA, there'd be no other place to put it.

if you are indeed correct about this, i dont mind tapping the other stock tube and getting data there. I have an extra yellow sensor probe as well as thermo wire twist probe.

The yellow temp is cooling air from the roof duct after it's passed through the IC. The sensor I used to measure cooling air flow through the IC has a thermocouple and pressure sensor too, so I was able to take all that data at the same time.
Just to add a little support to this... here's the graph of downstream cooling air vs. speed that I logged... note that there are 10-15 degreeF (6-8 degreeC) increases in the cooling air during high load periods... I'd expect to see some of that in the IAT if it was post IC..
.
OIC what you mean, right increeses in speed followed by heat transfered air... that makes sense. But this does coincide with the IAT data under the theory that it is post SC. JUst might not be able to see this in the graph made off the innovate data because 1) changes are almost instant. check the graph using the software, follow the time line towards the end where the cars running a bit harder, and watch the IAT and Load, there's definite correlation. 2) Keep in mind i was cruising to work for this session and not driving as one would in a spirited fashion. the session where I took 2 hard consequetive pulls was accidentally deleted, but reflected the correlation better because the fluctuation in IAT was much more volatile. There's a typhoon warning for tomorrow so might not get a chance to log some hard pulls but will do so and email to you asap.

Yes, at idle the SC is bypassed, so the air coming in from the airbox is not compressed, and should be roughly the same temp post IC.
right which also why it would rise inline with throttle when compressed...

you might be right, but hope not...
 

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Discussion Starter · #150 ·
but the MAF is really really "far" away from the TB and the fact between it is the rubber inlet and abs plastic on the box that act like heat gaskets. just find it hard to believe air rushing downstream would still yield such high heat soak. Also when i was monitoring the IAT, the temps moved really quick up and down, quicker than I guess heatsoak can. The TC4_3 IC inlet temps behaved more like a heatsoaked location would.




but that's cos that's the intake charge temp that goes direct to the intake manifold... as opposed to SC. I mean on an NA, there'd be no other place to put it.
Agreed. I was just wondering whether Lotus decided there was no need to change the location of the IAT sensor point.

if you are indeed correct about this, i dont mind tapping the other stock tube and getting data there. I have an extra yellow sensor probe as well as thermo wire twist probe.
That would probably go a long way toward answering the question...

OIC what you mean, right increeses in speed followed by heat transfered air... that makes sense. But this does coincide with the IAT data under the theory that it is post SC. JUst might not be able to see this in the graph made off the innovate data because 1) changes are almost instant. check the graph using the software, follow the time line towards the end where the cars running a bit harder, and watch the IAT and Load, there's definite correlation. 2) Keep in mind i was cruising to work for this session and not driving as one would in a spirited fashion. the session where I took 2 hard consequetive pulls was accidentally deleted, but reflected the correlation better because the fluctuation in IAT was much more volatile. There's a typhoon warning for tomorrow so might not get a chance to log some hard pulls but will do so and email to you asap.

right which also why it would rise inline with throttle when compressed...

you might be right, but hope not...
It's the schematic that has me convinced that the IAT shown as an OBD-II parameter is from the TMAF... the TMAF is labeled IAT in the schematic, and there's a large note saying that the temperature signal from the TMAP is not used.
 

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It's the schematic that has me convinced that the IAT shown as an OBD-II parameter is from the TMAF... the TMAF is labeled IAT in the schematic, and there's a large note saying that the temperature signal from the TMAP is not used.
:coolnana: let's swap the wires and see what happens :p no seriously shooting in the dark here, but assuming post SC is the optimal "correct" IAT position, perhaps lotus thought the engine could run faster and handle running on the "misinformation", and because they knew the IC couldn't cool charges enough anyways, so they left pre SC (knowing if they hadn't the SC cars would be dog slow). If so, any cars planning on boosting up, should seriously consider compensating for this eitehr via relocation or ecu map. Or... figure out a way to cool the charge down nearer to TMAF temps.

even though I am sure there's more inputs that determine spark advance (one of pids and logged), it would be interesting to establish thecorrelation between spark advance, fuel trims versus the IAT data. This would help us understand in relation to other inputs, which is most important. For example, I suspect ECT is pretty important but doesn't appear much attention is spent to control this variable. wheres the statistic/regression analysis software when you need it... time to dig through those econometrics class materials...
 

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Discussion Starter · #152 ·
:coolnana: let's swap the wires and see what happens :p no seriously shooting in the dark here, but assuming post SC is the optimal "correct" IAT position, perhaps lotus thought the engine could run faster and handle running on the "misinformation", and because they knew the IC couldn't cool charges enough anyways, so they left it there. If so, any cars planning on boosting up, should seriously consider compensating for this eitehr via relocation or ecu map. Or... figure out a way to cool the charge down nearer to TMAF temps.
Great idea...

If you get a chance to put the other sensor downstream of the IC the results will be very interesting...

EDIT: just looking at the IC tubes, they're not symmetrical... so you can't just swap them side to side... otherwise I would have said to just swap the tubes left for right...
 

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Great idea...

If you get a chance to put the other sensor downstream of the IC the results will be very interesting...

EDIT: just looking at the IC tubes, they're not symmetrical... so you can't just swap them side to side... otherwise I would have said to just swap the tubes left for right...
yea i dont mind doing it, not that hard to do... and Im sure someone on this forum who knows is having more fun watching us take pot shots. Watch, I'm going to start drilling the hole, and the second that happens the post will appear with the answer :sad:
 

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Discussion Starter · #154 ·
Well, I don't know if this is definitive, but this is what the service manual says about IAT... there's no exception listed for supercharged cars.

Intake Air Temperature P0111
P0112
P0113
P0111 Intake Air Temperature Sensor 1 Circuit Range/Performance
P0112 Intake Air Temperature Sensor 1 Circuit Low
P0113 Intake Air Temperature Sensor 1 Circuit High
Description
The combined sensor which measure both Mass Air Flow (MAF) and Intake Air Temperature (IAT) is incorporated
into the airbox.
The IAT sensor is a thermistor device which changes resistance with temperature. As
air intake temperature decreases the thermistor resistance value increases, and conversely as air temperature
increases so the thermistor resistance value decreases.
Sensor connections
Sensor Connector Description ECU Pin ECU Connector
1 Battery Voltage - -
2 MAF Ground 31 (D2) 52 Way (Right)
3 MAF Signal 45 (B4) 52 Way (Right) '06 M.Y. in brackets
4 IAT Signal 44 (B3) 52 Way (Right)
5 IAT Ground 18 (D2) 52 Way (Right)
Sensor characteristics
IAT -20°C (-4°F) 12.5 – 16.9 kΩ
IAT 20°C (68°F) 2.19 – 2.67 kΩ
IAT 60°C (140°F) 0.50 – 0.68 kΩ
Monitor: Continuous
The bolding is mine...
 

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Well, I don't know if this is definitive, but this is what the service manual says about IAT... there's no exception listed for supercharged cars.



The bolding is mine...
did you download this off that lotus site that cost like 25 greenbacks for one day? if so that's good news, the 2008 manual is out?

i see where it says IAT is in the airbox. damn it. sounds definitive enough. great find, this changes things.

I'll get to drillin...:nanner2:
 

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Discussion Starter · #156 · (Edited)
did you download this off that lotus site that cost like 25 greenbacks for one day? if so that's good news, the 2008 manual is out?

i see where it says IAT is in the airbox. damn it. sounds definitive enough. great find, this changes things.

I'll get to drillin...:nanner2:
I downloaded the manual and service notes back in February... it included a lot of '08 updates, including '08 schematics, launch control, new instrument panel, etc.

I wonder if there's still some way to make use of the temperature sensor part of the TMAP sensor on the intercooler. I noticed on Ocelot27's picture that it's actually tapped into the IC/intake manifold tube, where on my '07 its tapped into the intercooler itself... I'm assuming on your '08 it's tapped into the tube as well?

EDIT: I just realized that Ocelot27 has the RLS intercooler and tubes... so that's probably why his TMAP sensor is in a different location than stock
 

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I downloaded the manual and service notes back in February... it included a lot of '08 updates, including '08 schematics, launch control, new instrument panel, etc.

I wonder if there's still some way to make use of the temperature sensor part of the TMAP sensor on the intercooler. I noticed on Ocelot27's picture that it's actually tapped into the IC/intake manifold tube, where on my '07 its tapped into the intercooler itself... I'm assuming on your '08 it's tapped into the tube as well?

EDIT: I just realized that Ocelot27 has the RLS intercooler and tubes... so that's probably why his TMAP sensor is in a different location than stock
OK... are you sure of the wires on my pic and are you sure they aren't using this sensor for IAT - it makes absolutely no sense to measure IAT pre-compression?????? Charlie or Thomas HELP US!!!

I just want to know what wire to use to control the fans for my IC - there's conflicting info here and before I go cutting wires I'd like to know for sure what's what.

Also, you're right the RLS setup relocates the IAT sensor to the post-IC tube for those doing water/meth.

-john.
 

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From the '08 MY schematic:

You're looking at the TMAP Sensor...
Yellow (Y) is ground
Brown/Green (NG) is the temp signal
Slate (S) is MAP +5V
Orange/Green (OG) is MAP signal



If I'm reading the schematic correctly, IAT is taken from the TMAF sensor, which would put it pre-SC. The temperature signal from the TMAP sensor (post-IC) is not used...
Could they mean that the temp from the MAF isn't used in SC cars - this makes a lot more sense??? Plus why would they wire up the whole TMAP shebang and not use it???

-john.
 

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Discussion Starter · #159 ·
OK... are you sure of the wires on my pic and are you sure they aren't using this sensor for IAT - it makes absolutely no sense to measure IAT pre-compression?????? Charlie or Thomas HELP US!!!

I just want to know what wire to use to control the fans for my IC - there's conflicting info here and before I go cutting wires I'd like to know for sure what's what.

Also, you're right the RLS setup relocates the IAT sensor to the post-IC tube for those doing water/meth.

-john.
Well, I'm as sure as I can be in the accuracy of the schematics in the Lotus service manual.

You saw this excerpt from the schematic, right?



The wire color codes match up... and as far as I can tell the note about not using the TMAP temperature sensor is accurate...

Could they mean that the temp from the MAF isn't used in SC cars - this makes a lot more sense??? Plus why would they wire up the whole TMAP shebang and not use it???

-john.
I suppose they're using the pressure sensor part of the TMAP, just not the temperature sensor... without a schematic of the ECU itself (and it's software), I couldn't say what parts of the sensor are being used.
 

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Well, I'm as sure as I can be in the accuracy of the schematics in the Lotus service manual.

You saw this excerpt from the schematic, right?



The wire color codes match up... and as far as I can tell the note about not using the TMAP temperature sensor is accurate...



I suppose they're using the pressure sensor part of the TMAP, just not the temperature sensor... without a schematic of the ECU itself (and it's software), I couldn't say what parts of the sensor are being used.
Yes, of course I saw the schematic - the temps from both sensors are plugged into the ECU according to the schematic - correct? Even if the IAT is from the MAF I should still be able to use the correct lead (i.e. the "NG" colored one) from the TMAP to control the IC fans as several have done previously in this thread...
-john.
 
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