VN Commodore ECU update

[delcowizzid]

how did you make a 2 bar sensor im interested in knowing.to test it you can use one of those hand vacuam/pressure pumps they have a psi guage on them which will show vacuam and pressure.with nothing connected to the map hose it should be 2.45 volts for a 2bar sensor
14.31psi.....4.90V
14.00psi.....4.84V
13.00psi.....4.67V
12.00psi.....4.50V
11.00psi.....4.33V
10.00psi.....4.16V
9.00psi......3.99V
8.00psi......3.82V
6.00psi......3.47V
4.00psi......3.13V
2.00psi......2.79V
0.00psi......2.45V
5.00inHg....2.03V
10.00inHg..1.61V
15.00inHg..1.19V
20.00inHg..0.77V
25.00inHg..0.35V
29.10inHg..0.02V

[mag]

purchased a 2 bar absolute pressure sensor element that includes a hose connection, to which I have added an amplifier to get the appropriate ouput range 0-5 volts for 0-2 bar. although there is a 0-5 volt version of the same pressure sensor element from this manufacturer, they unfortunately are not available in Australia. the amplifier circuit etc. is as recommended by the the manufacture of the sensor element for producing a map sensor for automotive use. so far material cost has been approx $30AUS.

don't have a hand pressure/vacuum pump that is why I though using my na engine with a tee piece in the hose to the map sensor was the best alternative. if 2 bar map reads 0-1 bar ok ie 0-2.5 volts then 0-2 bar should be ok also.

[delcowizzid]

as long as it says 2.45 with nothing connected just measuring atomospheric air pressure 0.2 volts if you suck hard on the hose it may be ok if the amp is tuned right.yes you could fit it teed into the stock map line and measure voltage with a multimeter but you will need a 5 volt supply and earth to the second map sensor from somewhere.

[mag]

that's the easy part. so long as I get the correct output vs pressure Ill be happy.

[mag]

bench test of 2 bar map sensor successful. can change output by sucking & blowing. sensor vented to atmo gives incorrect output but I know why, goofed with amplifier setup. once correctly will fit to my na engine.

[delcowizzid]

i couldnt help myself i had to use holden202's favorite smiley schematics and pics so we can check out your masterpeice

[Holden202T]

yeah be interested to see how big this whole thing is ....

[mag]

unit currently in box 70mmx50mmx30mm. could be smaller but consider this size a good compromise for mounting on firewall etc. photo attached.

[Holden202T]

so on the right is the map sensor and the electronics on the left is the amplifier ?

[antus]

thats one interesting way to do a 2 bar sensor! nice work