I know this sounds silly but, can a person run 2 pyro guages off the same probe? The reason I'm curious is because I have a Autometer guage(Post Turbo) and a TST Powermax R46 adjustable remote(Pre Turbo). The Autometer is in the pillar and the TST is mounted very low which makes it kind of hard to focus on the road when the go pedal is mashed!! Will a guy get an accurate reading if I split the wires to 2 guages???

 

I believe that you will have issues if you attempt to connect two gauges. The probe is a Resistance Temperature Detector (RTD). As the temperature of the RTD varies, it's resistance will change on a very predicatable curve. The box associated with the probe puts an electrical signal into it. By measuring the electrical signal back out (varies with resistance) a very accurate temperature measurement can be taken. Adding a second circuit to your probe can create all kinds of issues related to the metering accuracy.

The TST can be programmed for max temperature before de-fueling. I would consider either adding another RTD post-turbo and using a lower setting on the TST or adding a second probe into the forward passage on your manifold for the TST and keeping the higher settings.

 

Ahh!!! Can the TST still de-fuel with the Smarty on SW#9????

 

I couldn't say right off the top of my head. The longer wire you run the more resistance so for sure your readings will be off if you run too much wire. The only question is, how much is too much? Best bet is to experiment if you already have the gauges.

 

Hmmmm......

AFAIK EGT probes use a thermocouple vice an RTD.

Check with the TST. I had one hooked up to a BD Cooldown Timer and a powered EGT gauge. Worked fine.

Jim

 

If you are referring to EGT defueling then yes, but only in regard to the TST defueling to stock feature. With the Smarty you lose the defueling below stock feature of the TST.

This is because to defuel below stock the TST fools the ECM, via the MAP sensor, to think it sees a low boost condition. With a low boost condition the ECM defuels as part of the stock SW. With the Smarty in your ECM brain, allot of thoughts about boost are gone. So even though the TST tries, the Smarty will not allow this to happen.

From my experience, watch your EGT gauge.....

Jim

 

Thanks Jim...

 

The probe should be a type K thermocouple.

Rusty

 

People make too much out of this. I've installed pyros in several pusher type RVs with over 30' of wire. There is no noticeable difference in readings from just 5' of wire.

You have to be careful when hooking up two gauges to one probe or two probes via a switch to one gauge that you don't create your own thermocouple by joining together two dissimilar materials in wires or switch terminals.

 

Not to get off track, but I will anyway, I have too much wire from my EGT probe, and its wrapped around my shifter boot under the floor console. Can I just cut it to the right length? I didn't want to back when I installed it b/c I thought it might affect the resistance reading.

 

The probe is a type K thermocouple. The output is microvolts. Circuit loading from 2 readouts will very likely introduce errors of too low readings. You can get in serious trouble while thinking you are operating at safe temperatures. Probes are relatively easy to install and fairly cheap as well.