05 Towing - EGT Questions

[CToney]

My buddy never had his probe in before he did the cam. He did the cam because the head gasket blew, it was in the shop so he figured he might as well try to reduce some drive pressure. I had to hound him to get the egt probe installed to see where the truck was for egt.

My understanding is the pistons, injectors, cam etc were set up for emissions and so the cat wouldn't plug the exhaust temp had to be kept higher. So if there was in cylinder egr, the egt would be higher and keep the cat clean and less NOx. If the exhaust flows easier wouldn't the turbo spool faster and flow more air and reduce egt. Is the restriction moved from the head to the turbine housing?
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I apologize for somewhat hijacking the thread but I'm curious at egt solution for 05s as well. I doubt anyone has just put a cam on a stock 04.5-07 engine there would always be other mods first. If the price of diesel doesn't drop like it should and stays high the fuel economy gain by changing a cam might be economical.

 

[AH64ID]

I ran my first cam with nothing else but a Smarty Jr, and I really liked it. There was a slight mileage increase, slight EGT reduction, but mostly it improved the low end response and spool when towing.

The 6.7 cam isn't ground nearly as restrictive on exhaust as the 5.9 CR cam is, since there was an EGR the cam could breath better.

Yes more exhaust means more turbo flow, but it's all a fine line between enough exhaust for a slight EGT raise/lower vs intake air.

 

[cerberusiam]

The cam grind on the 04.5-07's was intended for 1 thing, help activate the in-cylinder EGR. It, the 3rd event, and the tight turbo housing made the EGR work when the cylinder pressures and temps warranted it. A cam change is one thing to help the efficiency but you almost have to reprogram the fueling curves and timing to make a significant increase. It is a lot of work and $$ for the minimal help without other supporting mods but is one of the best hardware changes you can make.