Originally Posted by RPiM5
Also the titantium, while super strong and super light, is not the best metal for exhaust systems because it does not deal with heat well. Exhausts need to have flexibility of expanding and contracting in order to maximize air flow for heat disapation and power generation. That's why T-304 Stainless Steel is one of the best metals out there for exhausts and is RPi exclusively uses this type of metal. Just remember dudes, knowing is half the battle.
I'm not sure I get what you are saying there.
How does a Stainless exhaust expanding .5mm over its entire length help maximize airflow?
Also, heat dissipation from the exhaust (in general) would actually hinder performance. When exhaust gasses stay hot, it improves the scavenging effect, increasing power.