Ok,

I have ordered a BD Xmonitor for my 03'. I have read countless posts about mounting, but nothing about why one would put the probe in the pre-turbo or post turbo. I have looked at two older trucks with the probe mounted for the pyro and one has it after the turbo and the other has it in the manifold where it goes to the turbo. Neither guy could tell me the actual advantages to their way of mounting, only that each of them said that their way was the only way it should be mounted. They guy with the post turbo mounting said that pre-turbo would give at least 300 degree higher temp readings and would not accurately reflect the EGTs. Now i'm really confused, if many people mount them different and there is 300 degree difference between reading depending on mounting location, how would one know when they got into the danger zone EGT wise? What are the temp limits for each of the two ways of mounting the probe?

Which way is the best way and why?

Thanks,

CTDCAL.

 

Pre turbo will actually will give you a more useable number than post turbo. Pre turbo gives you the temp of the exhaust before it goes through the turbo and cools a bit. Pre will show the changes in heat more rapidly. This lets you know easier and quicker when you get "in the danger zone". Temp limits for pre turbo are 1200 degrees, and people will say that you can run higher. I try not to hold it on 1200 for a extended period of time. Post turbo would be like 800-900, I really can't say for sure. My vote is for pre turbo.

 

Always install it pre turbo.

This give the most accurate reading of how hot the exhaust flow is exiting the head. So you can actually prevent melting a valve or sending way to hot of gasses to the turbine.

After the turbo much of the heat is absorbed by the turbine and turbine housing. So it is not an accurate measurement of how much heat you are sending it's way.

That is why.

 

CTDCAL, if there is a 300* difference in the readings, then I guess when I shut my truck off and the pyro is pre-turbo, then my exhaust would really be at 0*, or sometimes as low as 50-100* below zero. Put it PRE TURBO and be safe. Hey that might be a good place to chill the beers when I get home??

 

Thanks for the info y'all, now it is making sense to me. PumpDaddy, I was just posting what I was told, did not say I believed it, its just my friend is so stuck on what he has done to his truck he thinks there is no other way. From what I have read there were obviously two different ways to do it, however nobody could give a definative answer as to why. Now I have it in a sensable way that is understandable. As far as the difference in readings on the gauge, I have not witnessed it, just saying what I was told which in turn prompted my post as I was suspicious and could not fathom such a vast diffence in temp between the two mounting places. It will be pre-turbo for me and my buds that are first time CTD owners having fun working them up to their potential.

Thanks again,

CTDCAL.

 

PumpDaddy,

I just read your post again, actually the guy that has his post-turbo was saying that the temp would read falsly higher pre-turbo and that false reading would not have any meaning. I questioned what he said and he got down right irrate about it saying that it how the probe was meant to be istalled per the instructions. He also said that if you mount the probe in the exhaust manifold it will only give you the reading from the particular cyl or cyls that the probe was closest too, that is why it would be a false reading. This did not make sense to me, therefore I posted up for clarification.

Thanks again,

CTDCAL.

 

that is true about the reading certin pistons but if the back 3 run the hottest then it is safe to say that is where you would put the probe.
DM01

 

On my car I run it at #1 because it typically runs the hottest.

You really want to sense the hottest.

If you must go your own way put it pre turbo in the collector area... where all the cyls come together pre turbo.

IMHO I really want 6 pyrometers. One per exhaust port and datalogging. I'll only hook the hottest one up to a gauge but record the others when tuning.