alms24sebring wrote:Are you effing serious!? How is that in any way better? They mean to tell me that the weight of eight bolts is too much? I bet it costs alot more to make it a 1 piece mainfold and head than just simple bolt on exhaust manifold. And I bet there is a cat right there, a foot down the pipe. What if that goes bad? This is what I mean, trying to improve stuff only makes it harder and more unnecessarily complicated.
Its not the weight of eight bolts they are merely contending with. First, the aluminum is a lighter material to work with. Second, a separate manifold requires a rather thick flange. Third, the parts of the head that hold the stud need to be able to cope with the mechanical stress of torquing down the manifold and the forces tugging at it. Lastly, with the integration of the manifold, the port no longer needs to clear the valvetrain enough to leave a flat surface to mount a manifold to. This means, the manifold could actually be a little closer to the cylinders, which translates to less material needed (less weight). Doesn't make it any better from a tuning standpoint, but there are good reasons to engineer it this way. Cost would probably be cheaper as well.
I'm not sure why you think a catalytic converter failure would be harder to deal with. Many current vehicles integrate the catalytic converter with the manifold. This can make it rather pricey and sometimes a PITA to replace. An integrated manifold design would ensure a catalytic converter would have to bolt on after the collector. I would much rather be able to unbolt the cat on my Titan than to remove the entire manifold. What am I missing here?
I did seek out some photos of the design to get a better idea of how it looks and here is a representation of it:
So what's the first thing I thought? All you need is an adapter to stick a turbo on there. HMMMM? The only questions in my mind are whether or not the integrated manifold design allows enough heat transfer to keep the temperature under control so the manifold section doesn't melt and is the cooling system up to the task of carrying that much heat away? Assuming they can, I say screw headers. Go straight to a turbo. More power anyways...