Will i was searching on ebay for my CAI pipes, i came across a few adds such as this one

http://cgi.ebay.com/ebaymotors/AEM-C...QQcmdZViewItem


they claim to prevent water from going into your engine and prevent hydrolocks.... anybody have any idea if this really works??

 

From what I've seen they do work, BUT you only need one of those if you're foolish enough to mount your intake low enough that it could actually be submerged in a deep puddle and you're stupid enough to drive though that puddle. Save yourself some money and don't do either of those things.

 

It also pretty much kills whatever gains you get from your intake. It WILL save you from hydrolock though.
Yes, it is stupid to drive through a deep puddle with your intake in the fender, but sometimes there's a sudden downpour or broken hydrant or something and you can't help but drive through it. If you have a CAI and your filter's behind the fender, it would be smart to get one. Especially if it rains a lot in your town.

 

CAI and Bypass valve???

 

it is a safty measure and they do work
the whole idea with a cold air intake is to draw air as close as possable from the ground.(hot air rises) and i dont think you have to be stupid to drive through a puddle, it happens.
i would recommend one

i dont think you will loose any gains that are even noticable, if any at all

 

how do these function? can i just get a ebay knock off???

 

also, should this go before or after the MAF??

 

well... if it's what I think it is... when the water gets sucked up it's heavier than normal air which requires alot of negative pressure to suck up... soooo... the by pass opens up thanks to the higher than normal pressure... and alows air into the intake (kinda the opposite of a blowoff valve) definantly put it before the maf so that the air gets metered... otherwise you'll run lean... and lean = boom.

 

Since it provides no additional restriction I don't see how that's possible.

That's BS. Mounting a filter as close as possible to the ground is just stupid due to the increased likelyhood of picking up dust, debris and water. The difference in temp from raising the intake 18" (about a biggest hight difference you could get) would be nothing, unless it's a very hot day and then the air close to the ground will be hotter.

Firstly you have to mount your filter really low, which I don't think is that smart. Then it has to rain hard enough to create standing water. Then you have to actually drive through the puddle without first thinking to yourself "I have a low filter, it's been raining hard and I'm approaching a puddle that might be deep." So yeah, you do have to be pretty stupid to suck water into your engine because it's entirely your own doing.

 

Someone told me that as long as the filter is not dipped in the water, then the small amount of water getting into the intake on a raining day does no harm on rotary?

 

A small amount of water won't harm piston or rotary engines, but you still shouldn't put the filter where it can get wet, because the water blocks airflow.

 

i c i c

 

in fact some people inject water into their intake manifold... LOL

 

i'm not sure, but it is possible this by-pass valve is merely another filter, if it is mounted in the engine bay it would be taking in hot air. but it could be a tightly woven filter, that way it doesn't really take in air unless the vacuum becomes great (if your entire filter in the fender/bumper is completely submerged). remember water doesn't flow up hill, think about trying to suck some drink from a cup without the straw being all the way down in the drink, it should be the same principle. and just food for thought, it looks as if it could easily affect the flow into the intake, that could reverse the gains if it is a negative affect on the flow.

jumbogum sounds right.

 

It's not, it's nothing like that. Read this:

http://www.sportcompactcarweb.com/tech/0104scc_tested/

This proves how well they work, but it still doesn't change the fact that they're only there to protect people from their own stupidity...

 

its called a valve for a reason. it is a rubber/foam diaphragm that only opens under a certain level of vacuum. its tight enought so that theres no chance of the diaphragm opening if the filter isn't clogged.

 

wow aem made a great idea! so then its worth it! as a precuation but u kinda shouldnt submerge ur car unless u live in luisiana.....then there was no choice..

 

It provides additional restriction by not being a smooth piece of aluminum piping.
To be honest, I can't say that it will kill the gains on a rotary engine, but on a Protege with a 2.0 in it, yes, it definately kills any gains you get from the cai. There was a huge thread about this subject on the Protege boards, and someone ended up dynoing their car and posting the results.

 

Repost. This is a thread from a while back. Just a few more thoughts...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/cai-question-466506/

 

why not just drill and tap your intake tube with a one way valve that opens at, say 5 psi, and then put a breather filter on that. that way, if the filter become submerged, it will be easier for the air to go in through the breather filter. same idea, much less expensive.