Turd is correct. Egts
get too hot while towing. Fuel=heat. With larger nozzles you can't pull enough fuel to keep it cool.
Here is a dyno video with 205/30 injectors and a stage 3 turbo. 688 hp ain't too bad.
This guy doesn't tow, so its moot in this instance. But I don't dig the idea of building a monster and not towing with it. That's sort of like building the baddest gun on the planet, but not shooting it because the loads are too hot.
Is it simply too much load demand and too much to ask of it, or is it an over fueling issue? It's the turbine that gets damaged right? So maybe a titanium turbine to better take the heat? I'm sure someone out there makes one. Maybe even relocate the turbo further from the manifold? Though with its oil setup on the 6.0, that would not be easy.
I mean, if exhaust is black, that's partially burnt so it's simply too much fuel or not enough air. There's nothing efficient about billowing coal, it seems unnecessary in my mind, even a waste. Can't the same power be had without the smoke? Sled pulling type of power notwithstanding, since all of them belch coal, so obviously at some point the smoke is inevitable, but not at 600 hp right?
And yes, 688 for my first one will be just fine. I plan on ringing the head, can't help myself, I'm intrigued. I actually had never heard of it until recently, but i read up on it and the machining is not complicated at all. Though my mill is no full blown Bridgeport, it's about 1600 lbs. more than big enough to handle this. I assume I'll be able to find some dimensions online. If not, a gasket would make a good template.