I have my setup running, back from a burnt Hyper piston. All forged 383, had to upgrade to a bigger turbo, s366 was too small for the new build, went with the Ebay GT45. I also needed a larger wategate to get the boost under control. I am very happy with the performance of this setup.

I installed a Pyrometer in my passenger side header, pretty much at the number 2 cylinder, in the header collector. There was a bung plug there so I drilled and tapped it to install my thermo couple. These used to be shorty headers that we turned around and fabbed up to make my hotside. I have a wideband as well, so I wanted the pyrometer just as another visual to see whats going on.

Timing is around 22 degrees at about 9-10 pounds boost, AFR is 11-11.5. 93 Octane pump gas. Not getting any knock. The hottest I have seen is 1500 degrees F. I have been doing some research and see guys that run hotter than that and some cooler. I know every setup is different. I just want to know what is considered safe for a certain length of time. This is in a truck that I plan to tow with. Now that I have burnt a piston, even though I now have forged pistons, I am a little timid.

I plan on backing the boost down to around 5 pounds or so while towing.

 

It's REALLY hard to say, A LOT depends on where the pyro is, how far from the port, how shielded the header tube is, etc. etc. Once you establish a "norm", you can then use that to see if something is going awry, but I doubt anyone that doesn't have the same exact setup as you will be able to tell you what normal should/would be.

 

^what he said

 

Ok, well I have been playing around with timing, and I did get them to go down some by giving it some more timing. I ordered a meth kit yesterday just to play it safe for when I am towing with the truck. My pyro is pretty much right at the number 2 cylinder, just an inch or 2 away. My headers are wrapped, and I have a turbo blanket. I am seeing 1200 just normal driving.

I have read about what temps to stay under, and they are all over the place.

http://rusubaru.com/egts-101/

They are talking about a turbo with an Aluminum turbine wheel, my s366 had an inconel turbine, I am not sure what the GT45 69/87 turbine is made of. Hopefully at least stainless steel.

 

The Subaru site you linked to is actually just a blog run by some moron that doesn't know what they're talking about. Hardly an authoritative source. The only turbines that have aluminum in them that I am aware of are Borg Warner's EFR line. Those are specially prepared with titanium and have physical characteristics that far exceed both materials. Most conventional turbines are made of Inconel or some comparable stainless superalloy.

Maximum tolerable EGT ultimately comes down to the lowest maximum temperature that the cylinder heads, valves, and turbine can handle. Turbos are often rated at 1600°F continuous, but lower is better. Ford used superalloy exhaust valves in the 1980s iron 2.3T because they idle at 1000°F and 1600°F under load is wishful thinking.

 

Thanks for the info, I was just googling and found that link.

I got the truck out on the interstate for the first time since its been back together and I was seeing 1500 cruising at 75 mph. Turning 2300 or so RPM. If I backed down to 70 it would drop to 1450 range. Timing while cruising is around 28 degrees, running stoich AFR of 14.7.

One thing I have noticed with this engine since I put it together, the temp gauge shows a little hotter than it used to. I think it is due to the aluminum heads pulling heat out faster than the old cast iron heads that were on it before.