I'm not a great believer in them. Placing a rotating mechanism in a 600C. gas-flow is not very wise. Many car manufacturers have problems with reliability of these items - including Lotus. Only the supercharged V6 cars leave the factory with them fitted.
Above is the 2bular install. I place the valve down low, in the airflow. Cooling of the vacuum chamber and its silicone seal is critical. HEAT is the enemy. I have had very few failures - but it's always been this part which failed. Easily swapped out for a fresh item.
I was sent this page recently by an 'interested bystander' -
For those of you who don't know, 'Bravo73' is the TLF moderator. I wonder how many spares of the German 'Capristo' exhaust valve vacuum chambers his buddy Greg Lock of Hangar111 has to carry. How many of these have failed?
Not that Bravo73 (or Greg Lock!) would tell you
I warned Komo-Tec about placing their exhaust valve high up in the exhaust bay (heat rises don't you know?).
Glad to see they followed my advice and now place their exhaust valve in the same place as 2bular! They also changed supplier - been there, wouldn't use them