Mauro has been heat-wrapping the Triumph TR5 exhaust using a Header Wrap. This is done to improve the exhaust flow and to reduce the risk of the Scavenging Effect. Scavenging occurs when the rush of the exhaust gas leaves the cylinder pulls in more fresh air and fuel.
It also lowers the temperature in the engine to reduce the risk of overheating. Wrapped headers will increase the torque and horse power by a small amount as well.