Thepersian

iTrader: (3)

Hi guys,

I've been trying to find some sort of discussion about using MS3 Pro with aftermarket gauges. Currently, I'm planning on getting the car ready to run the MS3 Pro. The car came with Prosport gauges installed. I've been doing a lot of searching on the diyautotune website and the forum here and haven't found a way to run the MS3 pro along with the gauges.

I thought about splicing the gauge wires into the wires from the sensors to the MS3 pro but the MS3 runs the GM based sensors and not the Prosport ones.

I'm not really sure how to approach this. I would like to use the gauges along with MS3.

Have any of you been able to do this?

Matt Cramer

Generally, an RX7 will have separate sensors for the gauges and ECU. Here are what sensors can and cannot be shared.

Coolant and air temperature - generally not sharable.
Tach - Wire it to the MS3-Pro's tach output.
Speedometer - the MS3-Pro can control an electric speedometer or share the sensor no problem.
Oil pressure - should be sharable, but you will need an output curve.
O2 sensor - most aftermarket wideband gauges have a separate output for the ECU, making them easy to share.
Boost - can probably be shared if you have the sensor output curve and it is an absolute pressure sensor. Sharing one with a gauge pressure sensor is not recommended.

Thepersian

iTrader: (3)

This gives me some ideas. I only have the following aftermarket gauges:

1. Water temp: I'll add the MS3 Pro sensor in the water pump (according to Aaron Cake's instructions), I'll leave the OE sensor and lastly, i'll hook into the return radiator hose with a bung that can hold the Gauge sensor.

2. Boost sensor: this is the easiest one. I'll splice into the boost silicone line with a T-fitting which will go to the GM 3 Bar map sensor for the MS3 Pro.

3. O2 Wideband: As you said, this should be easily sent from the Gauge output to MS3 Pro

4. Oil temp and pressure: This is the hardest one since there isn't room for 2 of each sensors in the pedestal. I'll have to figure out the curves and share a sensor.

Thepersian

iTrader: (3)

DOH!! The ECU doesn't need input for the Oil temp or pressure

Aaron Cake

iTrader: (1)

The basics of it is that your gauges and Megasquirt installation are completely separate. There will be no sensor sharing between them.

If you need to drive the tach with the MS3-Pro then you can however on a 2nd gen it is driven directly from the trailing coil.

As alluded to earlier in the thread, you'd want to use your own CLT and IAT sensors. No sense trying to share them and all the RX-7 IAT sensors suck.

Most widebands have an analog output 0-5V which the MS3-Pro will accept. If all you have a simulated narrowband output, replace the wideband with something that doesn't suck.