[Illumiloti]

Originally Posted by apk919

So, given a decent 20% increase in flow due to the first fettle, I thought I'd see how much more fettling was possible, as well as sealing leaks and smoothing flow.

There wasn't much more material to be removed, given the size of the ducting (see pics). There were gaps between the opening in the clam and the duct work though, and I sealed them with silicone caulking. Also, I worked on making the roof gaskets (for both the Cup and stock S roofs) seal more tightly with the clam opening. It's interesting that Lotus designed the gaskets differently... the Cup roof gasket goes over the top of the duct, the stock S roof goes under. On my S, there was a gasket attached to the clam to seal the gap above the duct. I don't know how a Cup car's clam gaskets look (pics anyone?). So I removed the gasket from the clam, and added a gasket below the duct for the Cup roof, and above the duct for the stock S roof. See pics...







































Now I need to road test... maybe tomorrow...

Pic #1: After completing the fettling.
Pic #2: After sealing the ductwork with silicone.
Pic #3: Cup roof mating gaskets.
Pic #4: Stock S roof mating gaskets.
Pic #5: Replaced the crappy hose clamps (Jubilee?) with decent slotted band hose clamps (Tridon). They're much easier to take apart, put together, and tighten down on the snorkel to the ductwork. Highly recommended if you ever take it apart.

I can't tell, did you also fettle the roof where it meets the clam? If not then that is a bottle neck that fettling the clam alone won't overcome. Is it even possible to fettle the roof?