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Rob H

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Formerly British Open Classic

The West Country

30th Oct, 2008 at 10:19:00pm

I'm after a bit of info on how these work if anyone can help, I know that they are effectively a resistor that varies in resistance as the air temperature changes but does anyone know what resistances relate to what temperatures?

I did a bit of a google search but all I could find was info on how to replace an IAT sensor and how to fit a resistor to give you and extra +15 BHP.

Isambard Kingdom Brunel said:
Nothing is impossible if you are an Engineer

Rod S

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5988 Posts
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Formally Retired

Rural Suffolk

30th Oct, 2008 at 10:43:38pm

An example of a Bosch one I was thinking of using...

The data for the Leyland/Rover ones is imposible to find, I decided to use Ford sensors instead as I have a copy of the relevant manual that has enough data points to put into the EMS...

http://www.bosch-motorsport.com/pdf/sensor...e/NTC_M12-L.pdf

Schrödinger's cat - so which one am I ???

Rob H

4314 Posts
Member #: 700
Formerly British Open Classic

The West Country

30th Oct, 2008 at 10:56:04pm

Cheers that's exactly what I was after.

Isambard Kingdom Brunel said:
Nothing is impossible if you are an Engineer

Rod S

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Rural Suffolk

30th Oct, 2008 at 11:03:03pm

No problem... there's temperature/resistance curves for the standard GM (USA) ones on the meagasquirt site somewhere as well.

The shape of the curves (ie, negative temperature co-efficient) are all similar but actual values on the curve vary from each manufacturer from what I found - hence the EMS requiring me to enter a number of points to set the curve.

(Edited for spelling...)

Edited by Rod S on 30th Oct, 2008.

Schrödinger's cat - so which one am I ???

Sprocket

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Preston On The Brook

30th Oct, 2008 at 11:44:20pm




On 30th Oct, 2008 Rod S said:

The data for the Leyland/Rover ones is imposible to find


*tongue*

Rover coolant sensor resistance readings, i had to scale this sensor for VEMS so i have a reasonable log of resistance versus temperature at 5 degree intervals, still got to measure 20,15, 10, 5, -5 and -10 degree points, but using Easytherm, it can generate curves from three points. I use a chip pan and oil to get the higher temperatures, but also to give a much steadier cool down rate so to stabelise the sensor readings as the coolant temp sensor is quite a large chunk of brass. It all took about three hours!! This was using Calibrated instruments, and is not representative of the two points I got from Lucas for these sensors!! which is 2000 ohm at 25c and 182 ohm at 100c

DegC - Ohms

-10 -
-5 -
0 - 5850
5 -
10 -
15 -
20 -
25 - 2066
30 - 1725
35 - 1433
40 - 1211
45 - 1030
50 - 885
55 - 756
60 - 643
65 - 558
70 - 481
75 - 419
80 - 367
85 - 320
90 - 279
95 - 246
100 - 218
105 - 192
110 - 172
115 - 153
120 - 140
125 - 130

On 26th Oct, 2004 TurboDave16v said:
 Is it A-Series only? I think it should be...
So when some joey comes on here about how his 16v turbo vauxhall is great compared to ours, he can be given the 'bird'...


On 26th Oct, 2004 Tom Fenton said:
Yep I agree with TD........
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