Well I called the local rotary performance shop and asked how much to install some gauges for me. When I asked about the egt probe being put in the turbo manifold they said they can do it but don't recommend it because of how weak the manifold already is. They said it would not be very much difference in reading in the beginning of the downpipe and would only be about a 6" difference anyways. What do you guys think?

 

Stay away from that shop that give you advice like that.
I'd like to know how a 1/2" thick cast iron wall is "weaker" than a 14-gauge mild steel wall of the downpipe.&nbsp The temp difference between before turbo and after turbo can be as much as 133&#176F - I see 40&#176C difference with my GReddy EGT gauges; the probe in the turbo manifold reacts significantly quicker.


-Ted

 

Well they said they can put the probe in the turbo manifold if I wanted, maybe I will just have that done. How much difference is 100 degrees farenheit when it comes to a/f mixture? Actually, (with the probe in the turbo manifold) what is the perfect temp you would want? What is the danger level? Do you think the 100 degrees is thorough through the whole rpm band and everything? Meaning will the difference be the same all the time(with the probe in the DP) do you think?

 

Technically, it has nothing to do with AFR's.

I have EGT numbers here:
http://n-xsi.com/HALTECH/tuning.htm
You might need to convert to F.&nbsp All EGT's are slightly different, so it might be off by + or - 200F in your application.


No, it's a percentage - not an absolute value.



-Ted

 

Turbos actually extract quite a bit of heat energy from the exhaust gases. They convert that heat energy into kinetic energy, which spins the turbine. This is why there’s a large temperature difference between the turbine inlet and outlet. I read somewhere once (but don’t quote me) that around 20-30% of the energy that drives the turbine comes from the heat energy, the rest from the force of the gases hitting the turbine blades.