f8sjester wrote:well. . . my friend has a '00 prelude NA with a CAI living in SoCal and he went through a puddle, sucked up some water, and totalled his engine. . . I don't know if it was just a whole lotta bad luck on his part but if I were to put a CAI on my car then i'd be dayam sure to get the AEM bypass valve. . . just for peace of mind. . .
It wasn't bad luck, if any engine sucks water up under anything more than idle it will probably be destroyed. The reason water is bad for your engine to ingest is because water does NOT compress like air, so if you suck more water into a combustion chamber than the volume of the chamber very bad things happen. Under light load (low rpm) the engine may just quit, best case senario you have to pump the water out. Under heavy load the the water could actually cause the cylinder head to come off, break rods, cranks, pistons, all kind of bad stuff. Water injection kits only inject a very small amount of water which is why they are safe. As far as a CAI on the turbo, if the filter were completely submerged it would suck water into the compressor (remember water doesn't compress) and probably just grenade the turbo. Oh and by the way, you wouldn't have to sit in a puddle for 10 minutes. I don't know exacly how much vacume an engine produces but its somewhere in the neighborhood of 25 inches of mercury. Mercury is WAY WAY more viscous than water, so 25 inches of mercury is like 25 feet of water (meaning the suction could suck water up a pipe 25 feet long). If you drive over a puddle and the filter is submerged it WILL suck the water up faster than you can say "OOH ****!". Hope this helps