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GM Flex Sensor Location and Coolant Pressure Sensors

Posted: Mon Mar 09, 2020 6:40 pm
by b.sanford84
Flex sensor location Curious if there is a preferred location for the flex sensor? I dont want it in the bay, I was thinking of mounting it closer to the tank. Would this be ok as long as its in the return line? flex fuel, says 9-18v, but can I power this off b2/d19 or should I get power elsewhere?

Coolant pressure sensors Im considering running of these as well. but, not really sure the optimal location for it. I thought to keep it out of the way, I could weld a bung to my water crossover tube and mount it there.

Wiring analog wiring , it states to power the sensors from the B2 and D19, at what point would there too many sensors (theyre all 0-150 psi 0-5v transducers) on those two locations? I plan on having oil pressure, fuel pressure & coolant temp is that too many to tap off b2/d19

Re: GM Flex Sensor Location and Coolant Pressure Sensors

Posted: Tue Mar 10, 2020 9:59 am
by Spunkster
I would recommend that you install this in the engine bay. I would recommend that you use switched power from the fuse box.

I'm not sure why you want to measure coolant pressure. Coolant temp should be adequate.

What version s300 do you have?

Re: GM Flex Sensor Location and Coolant Pressure Sensors

Posted: Tue Mar 10, 2020 4:47 pm
by Hondata
Coolant pressure can show when the cylinder head is starting to lift. If you put the sensor between the engine and radiator you'll get a big rise in pressure with rpm (from memory up to 45 lbs). Never tried any other locations.

Re: GM Flex Sensor Location and Coolant Pressure Sensors

Posted: Tue Mar 10, 2020 7:07 pm
by b.sanford84
I have version 3.

Why do you suggest the engine bay when the OEM puts it on the frame rail in their trucks?

Re: GM Flex Sensor Location and Coolant Pressure Sensors

Posted: Wed Mar 11, 2020 8:11 am
by DaX
Just as a data point, I have my flex fuel sensor mounted just below my FPR - see picture below. I'm running my flex fuel sensor off a 12V subpanel I installed that also powers my additional gauges, boost solenoid, and wideband.

The only person I've personally seen running a coolant pressure sensor is AZ_CIVIC on Honda-Tech, and his sensor is mounted directly into the head under the distributor...maybe repurposing the coolant temp gauge port?