I have a 07 RX8 I am looking at putting a cold air intake on. Im thinking about going with AEM. Any issues anyone has had with CAI or things I should be concerned and looking for would be appreciate the comments. Im worried about water and debris since the CAI wont provide as much protection as the box filter.

 

AEM is one of the good CAIs, so no concerns about the build or performance of it.

You are correct though, there is a minor concern about water with it. Taking it through a car-wash can give your MAF problems for a while afterwards, and often would require disassembling it to dry it all out before reinstalling. Easy to avoid though, by just hand washing the car.

The bigger problem, though rarer, is the fact that it significantly lowers the amount of standing water that you can safely drive through, to a matter of a few inches instead of a foot or more. Not that you should be driving through standing water that deep, but...well, people have done it. With a low pickup point CAI like that, you can very easily suck in a bunch of water all at once, where it will travel to the engine, fill a rotor cavity on the intake stroke, and then when the rotor tries to compress it on the compression stroke, AT BEST the engine stalls. More typically though the pressure has to go somewhere, and it starts breaking stuff, like engine seals and the engine block itself. Yes, it's happened a fair number of times on the forum, including puddles from a busted fire hydrant, storms, flooded parking lots, etc...

If you have comprehensive coverage on your car through car insurance, you can usually get coverage for the engine replacement if this happens, but still, you should avoid it in the first place, and avoid standing water at all costs.

 

Noted thanks for the response. Have you heard of any one adding a plate or some type of addition to protect from this matter? Obviously the best answer is to avoid water as much as possible. Additionally this isn't the first rotary I've owned or upgraded but I've never added CAI can you really notice a difference in performance? Thanks for the help!

 

No, I've never seen anyone take any safety measures other than just avoiding water.

No, you won't notice a huge gain, since the gain is about +2% at best. Mazda didn't release the RX-8 with a lot of untapped power, it's already pretty close to the bleeding edge of N/A performance. The only 'easy' gains left to be had are the ones where Mazda had to detune slightly to meet emissions regulations. Everything else is a huge dollar cost per HP.

 

My 2008 40th Anniversary Edition RX8 has a Mazdaspeed CAI (same as the AEM). I have had it for six years with no problems, and yes I sometimes take the car through a car wash and through unavoidable standing water. My Mazdapseed CAI has the sock which seems to offer some protection from water. The car wash I sometimes use does not use much water sprayed underneath the car, so no problems there. The car did gain a couple of hp and a small bump in mpg. I have owned seven RXs since 1973 and have had CAI on a few of them, and with care have not had a problem.

If you are really scared about the risk of water, then just don't get one. If you do get one, the AEM/Mazdaspeed CAi is the one to get.

 

I have a slight modification to my AEM intake, and never once had a problem with heavy rain / car washes / snow.

Technically, it would require you to submerge most of the filter itself in water before you start heavily ingesting water. (think of the hole-in-a-straw theory)

 

Haven't really heard or read about people having major issues with the AEM CAI, go for it