vauxhall nova multi function display

hi in my vauxhall nova i have a multi function display from a corsa, i want to use this display to show the boost readings form my turbo engine. i have found a site that talks about how to get the display to show what you want but im having problems getting my head around it all,

http://www.eelkevisser.nl/

the next problem is converting the reading from the turbo to a reading the display can understand? can any1 help me with this?

then after this i want to put in a switch to the display so i can switch it between showing boost readings and air/fuel ratio readings and possibly another reading of some sort.

can any of you clever people help me with this?

thankyou very much

chris

What you need is a MAP sensor. Its job is to convert pessure readings into volts. They generally require a 5 volt input and will put out a range of zero to almost 5 volts corresponding to pressure. I don't know what sort of input your display wants. Air/fuel ratio needs to come from an O2 sensor in the exhaust stream. These are a unit that puts out variable voltage corresponding to the amount of oxygen in the exhaust stream. They put out millivolts (up to about 700mv) so your display would need to translate millivoltage into a/f mix percent.

 Don't know if this helps or confuses!

yeah i can see how the readings are taken, i have a map sensor and id be very surprised if my mappable ecu doesnt have an o2 sensor. does any1 no how the figures from he map sensor translate to psi the turbo is producing? ie is one volt from the map sensor equal to say 10 psi or whatever? also does some1 no the similer figures for an o2 sensor so i can figure out what reading equals what percentage of each(air/fuel) is there

the web link above explains how the display works basicaly it works on the I2C protocol but id need to work out the calculation for the sensors so the display receives the correct figures

cheers

chris

hi i have found the following figures relating to map sensors could some1 translate them into real terms as they dont make much sense to me at the minute

MAP (Manifold Absolute Pressure) = Atmospheric Pressure - Manifold Pressure.

what i mean is according that table when the sensor shows 4.9 volts it displays 14 psi(1 bar) but when it shows 1 volt it shows 2.5 psi(0.4 bar) but if you multiply 2.5 psi by 5 you get 12.5 psi but 4.9 volts is 14 psi so how does that figure?

cheers

chris

Don't forget you need a map sensor capable of reading boost as well as vaccum. Most can only do negative pressure as chart shows.

also see this link http://www.yarchive.net/car/oxygen_sensor.html