RaceCapture/Pro MK3 in a 1999 Miata

General Q&A specific to RaceCapture/Pro. For app related questions post in the RaceCapture App forum. also see the <a href="http://www.autosportlabs.net/RaceCapture">RaceCapture Information Page</a>

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cybergeorge
Posts: 2
Joined: Mon Feb 17, 2020 8:39 pm

RaceCapture/Pro MK3 in a 1999 Miata

Post by cybergeorge »

Hi all,

Can someone double check a wiring diagram I came up with for our car? As a first stage, we want to get this basic data:

Sensors:
  • Fuel level
    Oil pressure
    Oil temp
OBDII:
  • RPM
    Engine temp
    MAF
RCP:
  • GPS
    Speed
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brentp
Site Admin
Posts: 5956
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi,

What temperature and pressure sensors are you using? Do you have the calibration information? This would be a chart showing the resistance value of the sensor across a temperature or pressure range.

Without this, you would be able to hand calibrate by taking resistance readings across temperature or pressure - tedious but possible to do.

The 1/4 watt 220 ohm resistor is fine for the 5v reference; the 180 ohm you should do 1/2 watt. You can safely use 1/2 watt for both.
Brent Picasso
CEO and Founder, Autosport Labs
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cybergeorge
Posts: 2
Joined: Mon Feb 17, 2020 8:39 pm

Post by cybergeorge »

Thank you, Brent.

We stopped working on the car because of the virus, but back on it now. The oil temp sensor is an Autometer 2258. Here is the calibration table:

ºC ºF Ohms
38 100 1123
49 120 708
60 140 460
66 150 374
77 170 253
88 190 175
99 210 123
100 212 119
104 220 105
110 230 89
121 250 65
138 280 42
149 300 32
160 320 25
171 340 20

The oil pressure sender is a VDO 360-410. Here is what I found:
http://www.chetcodigital.com/vGauge/vGa ... Tables.htm
It's the 5th sensor down on that list and this is the file they provide:
http://www.chetcodigital.com/vGauge/Fil ... _Table.txt

I get the first one but I'm not quite sure I understand the second one and can't find any other info on calibration. Does that make sense to you?

Are you saying there is a place to program these values into the RCP app? I'll look up how to do that. Are the resistor values ok, then?

For the fuel, we will calibrate every 1/8 tank. That should suffice.

brentp
Site Admin
Posts: 5956
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi - there's a guide at the bottom of the page here on how to map sensors:
https://wiki.autosportlabs.com/RaceCapturePro_Sensors
Brent Picasso
CEO and Founder, Autosport Labs
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