Power FC Map Sensor Solution?

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08-18-04, 06:11 PM

Zyon13B

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Map Sensor Solution?

Ok, I've been searching for a long time, and as far as I can tell, this is never addressed. Maybe it won't work, but neways here goes.

Does anyone know what bar the map sensor with the AVC-R can read to? If it is a 3 bar sensor, could the readings be sent to the PFC and the AVC-R from one sensor? Possibly by spliceing the ecu harness to the avc-r harness that plugs to the sensor, which both have the three wires? Or would that throw off the readings?

Any thoughts? Am I making any sense?

Also posted this in the single forum.

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08-19-04, 08:56 AM

cewrx7r1

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Quote:

Originally Posted by Zyon13B

Does anyone know what bar the map sensor with the AVC-R can read to? If it is a 3 bar sensor, could the readings be sent to the PFC and the AVC-R from one sensor? Possibly by spliceing the ecu harness to the avc-r harness that plugs to the sensor, which both have the three wires? Or would that throw off the readings?.

The AVC-R manual should tell how high it's map sensor is good for since that would be about the max boost you could program it for. If it states being good to 3 bar, then that is it. Very simple basic resoning!

There are two issues with tapping into the AVC-R map sensor output to the PFC to replace your stock map sensor: (1) impedance loading of the output.
Example; the O2 sensor output voltage and current is so low that is requires a very high impedance device to read it. Otherwise it is overloaded and the voltage drops giving a false reading.

To test this out, splice in to the AVC-R map sensor and measure it's voltage with a high impedance digital volt meter. Test this at idle and maybe 0 boost. Then connect to the cars wiring where it goes to the PFC and disconnect the stock sensor. Then remeasure the voltages. If the same then you are not overloading it.

(2) voltage output per boost scale might be different than stock. This you would have to measure and plot from vacuum to boost and then change the P row absolute values to match up, using a DATALOGIT. Not really difficult to do if you understand the basics of what you are doing. Voltage to boost scaling can be done just using the Commander and an air pump. First do it for the stock unit than using the AVC-R output. I have done this comparing my AUTOMETER boost gauge to the stock sensor readings on the Commander and to the reading from my Blitz boost gauge which uses it's own 3 bar sensor.

Last edited by cewrx7r1; 08-19-04 at 09:00 AM.