Exhaust for a 427 CI LS7, collective per side is 800-1,000 degrees per side, much more hotter then short exhaust of a motorcycle
Well proven that wrapping will cause a higher expansion rate of the thin pipe then the thicker weld
Also went cooling the trapped heat causing condensation which then effects welds.
Makes no difference if the CATs are wrapped, it is the facts the hotter trapped heat of exhaust will effect all 4 O2 sensors
which then cause the PCM to falsely command fuel injector ON times
Now with hotter temps as the math of PCM is done by what the O2s reports, trips the CAT overtemp function and injects more excess fuel in to attempt to protect the CATs to cool them down, which effects performance of engine.
Use of larger volume radiator, water/methanol, engine oil, tranny and transaxle coolers, along with venting hood will reduce overall temps.
Example below of what headers look like when wrapped and cracked weld.
Thank you for voicing your concerns. I truly appreciate them.
However, I find the weld issue rather specious, especially given all the welded and wrapped motorcycle pipes out on the road.
As for the CATs, I do not intend on wrapping them, only their surrounding pipe. If anything, the increased heat and resultant flow should make them more efficient.
Now for the O2 sensors. Your concern is a distinct possibility, but in all my years of racing never have I confronted that.