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This is the best thread EVER! :clap: :clap: :clap: :nanner: :nanner: :clap: :clap: :clap:




Do you think it would be beneficial to run the roof scoop to the airbox (where the snorkel currently enters)? Then one could take Shoco's side-inlet kit to improve airflow over the intercooler, and the roof duct could then be used to provide cool, clean air to the airbox.

I've looked at my engine bay a bit and even with the i/c installed it seems like there is enough room for a few bends and flex pipes to run the plumbing and it shouldn't interfere with opening the hatch either. The airbox doesn't need a massive amount of air going to it. It just needs access from which to pull cool air, and enough of it circulating around. Just curious as to whether or not you think this is a good idea, based on both your experiences in evaluating airflow through the roof scoop.
Smoky, I love this idea, if it's doable. I'm having the Proalloy chargecooler installed (Sector 111 is using my car as the fitment test mule). I'm thinking, hmm, now I've got this scoop on the roof in cool air doing nothing. Maybe I can direct the flow into the airbox. Would it f up the fuel/ air ratio I wonder?
 

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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?
 

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The thickness of both roofs at the clam interface is no thicker than the rubber gaskets used to mate them to the clam... so it really doesn't seem that there would be any practical benefit to fettling the roof.

Without changing the external dimensions of the roof or the clam, I think I've gone about as far as possible be fettling alone. If I were designing the roof and the clam from scratch, I'd definitely make the "mohawk" cross section wider and/or taller.
Then, to my mind, if the roof is only allowing x amount of air to pass into the clam and there's no way to open up the roof any wider, it might flow more air WITHOUT the roof or with a roof sans a scoop. Then (correct me if I'm wrong) you could fettle the clam opening even larger because you wouldn't have to worry about a mating surface (to seal against a roof).
 

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This is why I went with a water/ air chargecooler. There is simply no way to get enough air through that mail slot of a roof/ clam to effectively cool the charge. (no matter how much fettling of the clam you do, the roof opening going into the clam is what it is). The RLS is a bigger/ "more efficient" intercooler but it can only be as efficient as the air flow through it. Are you going to test with water/ meth injection? That would, I'm sure, make a big improvement.
 

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I also think this will work better than an air/water IC - same soak issue with this solution only it just takes longer to saturate the systems water volume with heat - better just to blow the heat right the hell out of the engine bay with big fans.

-john.
Assuming the water to air has a sufficient heat exchanger and pump, why would this happen? The engine water temps are kept at a constant level with a properly functioning system, why wouldn't the same apply to a water/ air intercooler utilizing the same principles?
 

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Sorry i dont mean safety if you were to roll over, but whether there could be damage to the intercooler/supercharger if poor airflow was apparent. I understand the roof scoop has no bearing on the engines cooling as a whole, but wasnt sure if the supercharger side of things could get damaged.

I think everyone agrees that if on track, or driving hard everyone keeps the roof on. But it would be nice to confirm for sure if driving topless on a sunny day will not cause any problems.
Well, since Lotus now sells an Elise which is supercharged and they don't even bother to put an intercooler on, I think that answers your question. The bottom line from all this testing is that there simply is not enough airflow through the "mail chute" at the top of the clam (or the back of the roof that connects to it) to allow the intercooler to do it's job and prevent heatsoak. So roof on/ roof off ultimately doesn't matter (regardless of what the salesperson at the dealership tells you). You're just gonna lose a bit of power once everything gets hot.
 
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