Originally Posted by Jolly Green Monster

seems to be some misunderstandings here..

not only do you increase the gas speed the main gain is in keeping heat out of the engine bay it has nothing to do with getting every last bhp.. with regards to fire and issues I have seen more melted looms and engine fires with unwrapped headers than wrapped.. oil leaks are simple to check for and unless the leak is an instant failure in which case unwrapped or wrapped you are likely to have an issue you shouldn't be on track with an oil leak anyway.

Ceramic headers work well but the ceramic doesn't last forever and peels off over time, although wrap depending on make doesn't last forever either, but is easy to repair in situe and can be used on old headers where as ceramic needs spotlessly clean headers.

I have ceramic coated on one of my cars and wrapped on the other.. the wrapped headers keep the noise in much better, the ceramic sound like there is leak.. but the ceramic coating (in white) would show any leak..

Given the choice I would wrap them with decent quality wrap, there is no option of leaving tubular headers bear imho.. too much risk of melting something or fire if a sudden leak.

As to Det it actually reduces it.. the gas flow is increased therefore on the exhaust stroke the cylinder is cleared of the exhaust gas better, leaving the cylinder emptier of left over combustion gas for the next cycle.. so you gain power, torque and less chance of det as the charge is much cleaner/ fresher in the cylinder.. also intake temps are reduced as well as engine temp in general as the engine bay temperature is lower, back pressure is reduced.

Simon