This was brought up in another thread and got me thinking. I want to have a seperate guage for my egt from the attitude monitor. This mostly a precaution if I have to take it in to the dealer for any reason but it would also allow me to free up a parameter on the attitude display. While I dont think you can just wire the three connections together and have it work properly I was curios if it is possible to diode isolate each line. I am guessing that the probe changes resistance with temperature and thats how the readings change and adding the second pickup would change the resistance but wouldnt diodes fix this?

 

Looks like a good question for Drew, Jakebrake or Steveoramma.

 

I believe Drew said earlier that it will NOT work because of the current draw between the two gauges. He's already tried it and confirmed it.

Sorry ..

 

EGT works off of a millivolt signal and you can use one probe and read it from multiple locations without degradation to the signal source. Most signals that output in volts can be read from multiple devices. Other probes that have current signals can be limited in thenumber of reading devices due to current limits.

 

I have both my Isspro EGT gauge and TST monitor connected together with no problems. They all work with about the same voltage so, I don't think it'd be a problem with most brands.

 

The gauges should have a high impeadance input to measure the thermocouple voltages so there should be no problem doing it. the best thing to do is to try it and test it... do this...

1) turn off any go fast goodies you might have
2) connect meter 1 (attitude monitor or gauge) to the probe,
3) fire it up, pop it in neutral and rev it up to 1500 rpms for about 10 seconds
4) record the egt measurement
5) switch over to the other gauge using the same probe and repeat steps 3 & 4
the measurements should be fairly close, +/-5~10%
6) connect both gauges at the same time to the probe and repeat steps 3 & 4
check that the measurements are still within +/- 5~10% of the 1st readings for
each gauge, if they are your good to go and you know 1st hand whether it'll work or not.

the idea here is to get a base measurement, then compare the different setups against it, you will need to make sure your base measurement is repeatable. If having both connected gets your egt measurements off a little, then you can compensate for it in your attitude monitors max egt point and your cool down temp.


I'm going to be working on my truck today and can possibly toss this into my work as I have an egt gauge in the dash that is not connected because of the tst... If I can get it done, then I"ll post back results here.

 

I would appreciate that steve.

 

What cha doin ??

 

swapping diff fluids, finishing off the gauge install (few wires left) and scoping out a spot for an aux fan up front... I want to put 2 10" fans up front to help out the a/c and help minimize heat soak on the innercooler during stop & go traffic. anything bigger than 10" wont fit... not enough room.

 

Be sure to take plenty of pics !!!

Good luck brotha !!