hello. i remember being able to read about pyro's on isspro's website a while ago. the reason i'm thinking about this is that it talked about not letting your EGT's drop too fast when cresting a hill, but i can't remember what the reasoning. anybody have any info on this? thanks

 

Thermal shock. Some lousy engine designs are known to crack exhaust manifolds and even heads from this sort of thing. That's why big truck sixes have 3 piece exhaust manifolds. The Cummins 5.9 doesn't seem to be prone to this.

 

The 12v manifolds shrink (mine's shrinking) and can break the ears off the head. The 24v manifolds crack in the middle below the turbo. This is why these exist- http://atsturbo.com/DoManifold.html

 

I know dodge fixed the problem with the ears. I didn't know there was another problem.