Jeal's air filter box certainly looks neat and, as it's made of carbon fiber, it's light as a feather. But, the short intake duct that comes with it, misses the mark, IMO. I've seen the Jeal box on other cars and when the underhood is at operating temp, the rubber/plastic or whatever it's made of kind of sags down into the air flow.
I had considered putting a Jeal air filter assembly on Vette's "Purple Project" car and, in preparation for that, ran some dyno tests with the stock air filter box modifed with a K&N Filter and a DRM open-element top connected to a stock duct vs. no filter or duct at all and there was no change in performance between the two. That means to me that the addition of the Jeal airbox would not affect performance IF we assume that performance with an air filter assembly could not be better than no airbox or duct at all. After that test, I decided I didn't want to go to the trouble to cut the hole(s) necessary to mount the Jeal box.
Now, the Jeal air filter box is one of those that takes air from the cooling intake. My test did not take into account any performance increase via the ram air affect that might come into play once the car's speed gets over 100 mph or so.
As for air ducts, rather than forking out money to buy an aftermarket air duct, I performed a trick I've seen on a couple of cars owned by resourceful Zroners. I made a small, steamlined, aluminum brace and screwed it inside the stock air duct. With that brace there's no potential at all for the duct collapsing and my dyno tests show inserting the brace has no affect on performance.
