What's does this channel next to the exhaust port do?

[Jon Jon]

Hi Guys

I'm in the process of fitting new hi-flow cats/tubular manifolds to my 987 Boxster S (2006 model) and when I removed the original manifolds I came a rather strange looking channel that runs along the length of the mating surface. Does anyone know what this does? I've included a photo with the tip of a screwdriver pointing to it.

Also, when buying replacement manifold gaskets from Design 911, I notice that they supply two types. The standard one is about £8 and then there's one referred to as "cooper" and cost's £60. Does anyone know what's special about the latter.

Thanks in advance,

Jon

[captainblakk]

Secondary air channels, electric pump sits on top of engine & pumps air into exhaust, mainly on coldstart to warm up cats quicker

[LiamH66]

Jon Jon said:

Also, when buying replacement manifold gaskets from Design 911, I notice that they supply two types. The standard one is about £8 and then there's one referred to as "cooper" and cost's £60. Does anyone know what's special about the latter.

Seems a bit odd. Cooper's rings (i.e. gaskets) are normally used for cylinder heads, and are a hollow ring filled with pressurised gas, but you normally have to machine the head (or cylinder block) to be able to fit them. Work amazingly, but cost a fortune, especially with the machining needed to fit them. I'm wondering if they actually mean copper.

Either way, if the mounting faces can be made made clean and flat, I'd be going with the original style gasket. Might be worth a call to Design 911 so they can explain what they are, and why you might need them.

Liam

[Jon Jon]

Thanks for the replies. Much appreciated.

Jon