Hey guys,

Found a very lightly used Mazdaspeed CAI for sale on my local craigslist. It's only been installed for about 1500km on a car and comes in the original box with all the parts. How much would something like that normally run you?

Cheers,
Deth

 

200$

 

Check and be sure it comes with the sock to go over the air filter. That was a standard included piece . Due to the low position of the air filter to get the coolest air, it is important to have this filter sock to prevent any water ingestion into the filter if your drive through heavy standing water or go through auto care washes that spray water up into the underside of your car. I have had my Mazdaspeed CAI on my RX8 since 2009 with no issues at all.

 

Save your money for maintenance items or suspension/tires , intakes are a waste of money unless they are attached to the compressor housing of a turbo.

 

I disagree 9krpmrx8. and have had them on several of my seven rotaries over four decades. The good ones (Mazdaspeed is one of the two good ones for an RX8) give a slight power bump on NA engines and gave much more on my boosted RXs

 

Please stop stating in every post how many rotaries you have owned and for how long, it is really annoying to read that in 95% of your posts.

And you can disagree all you want, but real world data matters. The stock intake has a ton of R&D in it specific to the intake system on the Renesis and it works very well and filters very well. The aftermarket intakes are mostly noise makers that net you maybe 5 wheel HP on a good day and that is being very generous if you have ever seen a RX-8 dyno day. But the worst part is that they don't filter well at all so you are purposely allowing you engine to suck in more dirt, sand, etc. Not to mention that plenty of people (search) have had issues sucking up water with the AEM/Mazdaspeed even with the sock so that is an added worry that an RX-8 owner doesn't need.

 

9krpmrx8, then just don't read any posts from me, simple. A good CAI can net you up to one hp for each 10 degrees colder your intake air is, on a healthy rotary engine, depending on altitude and atmospheric pressure. That has been my experience over my long history with the few good ones that don't actually rob you of performance. Other rotary owners' experiences may be different.

BTW I have never made any claims beyond a few hp with the Mazdaspeed CAI, so be sure you attribute any wild hp claims to someone else. Over a million rotary miles, with maybe half of that with CAIs (good ones) and personally never had any water ingestion problems, or filter problems and never had a failed rotary engine, ever. I am either just lucky or perhaps maybe I know how to use them, just maybe. LOL

 

And where did you get your 1HP per 10 degree colder numbers from? Have you measured and compared intake temps from AEM/MS to the stock intake? Dyno tested before and after with one?And you may have never had any filter problems but non the less you are ingesting a lot more dirt than you would be with the stock intake and while water has not been an issue for you, it has been for many.

 

Do not all of the RX-8s come with a cold air intake? Maybe it's just an R3 thing, but mine sucks from the front bumper.

 

Yes they do.

 

So where does this aftermarket intake pull its air that it's so much colder, the air conditioning vents?

 

The research and figures on this for rotary engines is years old, I think it was either Pettit Racing or Racing Beat that came up with the figures. I will find it and post it. It is matter of pure physics based on the volume of air in a 13B sized combustion chamber, air density and combustion characteristics of rotary engines. It has long ago been proven on dynos and is the basis for every record-breaking rotary land speed record car that was developed by Road and Track and Car and Driver. A cooler intake charge, either from a CAI or in conjunction with a dry ice system yielded more hp for better performance from their 13B engines.

To answer the other question if you look at where the Mazdaspeed/AEM CAI puts it filtered intake it is from the maximum forward and low position available on an RX8 chasis much lower and further forward than the stock intake, thus less prone to sucking in hotter engine bay air.

The filter is basically a very good K&N type filter system which has been used for decades on street and racing RXs without dirt in the engine problems. Honestly nothing is going to convince you about all this, but just trust that those of us that came long before you knew and still know a little something about these cars and engines we have been driving and modding and racing since before many of you were born. LOL When I find those figures again I will post them, I promise.

 

Gwilliams, the history of the rotary and cold air intakes in general has nothing to do with the Renesis, you cannot compare them in any way. Do you understand how different the Renesis induction system is different and far more technical from every other 13B made ever?

Yes the K&N is great at filtering, that is why the Rolex RX-8 race cars switched to OEM style paper filters due to the amount of dirt they were getting in the engines just during one race? You can read Eric Meyer's (member here and RX-8 race car team owner for those who don't know) and others discussions about this topic in a few threads here.

 

My experiences are with both the 13b and Renesis. You seem to think you are the only one with any background and first hand knowledge of anything and everything rotary. I know just as many racers over the years including some running Renesis engines that have run K&N type filters with no problems like you describe should be happening to them all the time, but oops they aren't you and you know all, sorry. I have great respect for the Speedsource folks and their RX8 setup on a THREE rotor motor, tube-frame race car. I am only talking about two-rotor engines
and the 13b and Renesis. I never owned a 20B.

I read all those threads long ago, but you seem to leave no room for others to disagree with you or you don't believe anyone can have a different experience than the experience YOU choose to believe. There are hundreds of different experiences and stories out there to make any particular point. If one thing 43 yrs of driving these cars on street and track and using about every mod that came down the pike for both NA and FI rotaries has taught me, there are loads of different ways and products that can help you achieve better overall rotary car performance if you are open to different ideas and willing to be wrong until you find what works for you. I talk about what has worked for me and has worked for others I know and know of. You speak about what you know and so do I. There is always room for disagreement and debate because there is NO one solution for each different setup and different driver and different car and different race series. I have followed your posts on various threads recently and boy are you have a disgruntle, argumentative time now on many topics ! You need to learn to keep an open mind and not only believe that what you say is absolute. Folks were driving and modding and being successful with these cars long before you came around to dispense your absolute truths.

 

A K&N filter doesn't filter that well, it doesn't matter what engine it is on. This is common knowledge. There have been countless tests proving this and showing the huge difference between a good paper (not really paper) filter and the K&N, it's not really debatable.

Is running one going to blow up you engine? No. Will running one induce more dirt, sand, etc. into your engine? Yes. Especially when the filter is mounted down low in the grill of you bumper where it will inhale everything as you drive.

 

I disagree , in my experience with these non-paper filters if made to tight tolerances have been used effectively on street and racing machines of all brands, including rotary, without the issues you suggest are not debatable. I lived this and used this, not necessarily always K&N but similar, and some very different but also non-paper, also used by Racing Beat and Pettit Racing teams without the issues you say are not refutable. Trust me, even with your great infallible knowledge (LOL) you don't have the complete evidence on all these race teams and what they have used, nationwide and worldwide. Certainly paper filters have gotten better, I agree there. But many of Mazda's Class winning 24 of Daytona Winners and IMSA GTU. GTO and Camel Lights championship rotary powered cars used non paper filters. I have been there, seen them and helped work on some of them, and none of their engineers and crew believed they were better off with paper filters, none.

And not even all Renesis powered race teams use paper filters. So are these crews less knowledgeable than you in all your great wisdom ? Non paper filters can be just as good and durable as paper air filters and can offer significantly greater air flow and greater dirt and dust holding capacity with the right construction and materials. The rotary world is not going to suddenly all switch to paper air filters because you say they should.

 

I am well aware the K&N (owns AEM, Mazdaspeed, etc) are widely used on the Renesis race cars. But that doesn't mean they filter better. 90% of racing is monkey see, monkey do, so your point is meaningless. As I said, they don't filter nearly as well as an OEM style filter. Period.

And the OP doesn't have a race car so installing an aftermarket intake that offers no tangible performance gain and at the same time does not properly filter the air that the engine breathes makes no sense at all.

FYI, the custom intake setup I made for my turbo setup uses a K&N sadly. It's just not placed in front of the radiator where it will constantly suck up dirt.

 

Clean, so I don't have to look through your thread, where are you venting back at on your intake? The intake I have from your favorite guy at RXPerf. , Scott placed the return in a rather crappy spot that I would like to correct...

 

Yeah he sucks and his intake sucks too. Look at the first post of my build thread, you can see detailed pics of my recirc fitting there.