A turbo'd engine has much higher inlet temps though......
and these are also sold and very effective on atmo cars, 16v, VR6 etc, insulator is an insulator, and conducted temps from manifold is actually slightly higher on an atmo car, as intercooled turbo cars when running an efficient intercooler run cooler intakes... up until they hit start-stop traffic or slow running then heat soak like any car from rad fans blowing etc.
I know full well what turbo cars and atmo cars run like temp wise, and the insulator gaskets work on both.
when t'bodied my 16v fuel rail would sit at 95'C after a session without an insulator gasket, and was 65'C in same conditions with one fitted.
thin ptfe gaskets vs phenolic thicker ones, favours the phenolic when used on another brand I work on. (VAG)
PTFE is compressable, which over time has allowed some creep and subsequent air leaks. Phenolic is'nt