just did this today, didnt notice much of a sound increase but i have not driven since. Didnt have any idle problems either but I assume its because of my cobb ap custom tune.

probably going to install the airduct eventually.

 

@Hi

So screens smooth out the pulses going down the pipe by being just a tad restrictive (grade my reading of that paper with only 1 cup of coffee). This would in essence dampen any oscillations in flow that are making it up from the tuned ports and SSV stuff.

@ everyone else, cleaning those screens periodically, especially for those like me that run oiled filters, is important. They are supposed to be very thin wires. Add a little dirt and they can be restrictive.

I am only running 1 screen, and I probably need to clean it next time I clean the MAF.

 

Being sick and all, I decided to bear with my weak self to do this mod today. The process of removing the damn air box sure didn't help me feel better. Anyways, I removed both baffles and one screen inside the horn assembly and cleaned my MAF sensor in the process. I gave it a test run and didn't really notice a difference in sound aside from some slight hissing past 6,000 RPM. (Possibly because of my Borla taking over) The idle is a tad rougher as well, it jumps around 900 RPM - 1000 RPM occasionally. (I didn't do an ECU reset, so I'm sure it's adapting to the change of airflow). What I did notice though is that the revs are smoother! I'll keep this mod on for that reason and hopefully the ECU adjusts by then and goes back to normal idle. If it doesn't, I'll probably just put everything back in. One last thing I need to get is a good aftermarket air filter; I was considering K&N, but it seems to be a hit or miss with most of the members here, but I'll do more research.

 

Save your money, the oem filter does the job well. Mazda didn't skimp there.

 

Thanks, I appreciate it. I just did a full reset on the ECU by pumping the brakes 20 times and disconnected the battery for 15 minutes as well. I ran the car for about 20 minutes afterwards around my neighborhood to let the car learn the new fuel trims.

Noticeable Differences:
-Revs are a bit smoother.
-No more rough idle after driving the car for a period of time after the reset.
-Low throttle intake whistling along with a tad more aggressive engine note at high RPM.
-Car isn't as jerky on low gears.

Unnoticeable:
-No gains. (No surprise there)

 

It's probably posted in this thread somewhere. I'll repeat it anyway.
I ran a test on this mod using a friends 05 RX8 with a auto trans. It was tested with a ScanGuage connected to the ODB II port. Removing just the plastic veins in the air box showed a sizable increase of "horsepower". It is likely the ScanGuage equates this hp measurement with the amount of air moving past the MAF sensor. However, as we know, an engine is an air pump. The more air you move through it, the more hp you are making.
Removing one of the screens removes more restriction and would have likely showed even greater gains. The mod did take place in an active parking lot and we were reluctant to do anything more extensive at that time.

 

I actually did read your posts about using the ScanGauge; it's one of the reasons why I decided to do this mod after doing quite a bit of research. Very nice to see that the removal of the front screen and baffles increased the airflow. I do believe that there was a very slight increase in power overall, I just meant to say that I didn't notice it using the "butt" dyno. Obviously, nothing is better than a good breathing engine, so no regrets so far!

 

^This. I took the attached picture last week during testing for 24 hours of Rolex at Daytona. That is a 20b racecar with a OEM air filter in place If its good enough for those situations, its good enough for the street.

 

Kudos for the pic. I'll definitely ditch the idea of getting a high flow filter and stick with OEM.

 

it looks like 5 OEM filters to me ...

 

No, just an OES (aftermarket) filter perhaps, although you're correct is does look a tad looooong being front to back like that in the engine bay lol > 2004-2011 Mazda RX8 Air Filter - Air Intake - Genuine 04-11 RX8 Air Filter - 8610-01100271 - PartsGeek

 

When Speedsource was running the RX8 they were using genuine Mazda OEM air filters on their car. I saw a stack of them on a cart shelf in their Daytona garage. They said that the K&N filters let too much grit through, especially the sandy type found at Daytona.
The Mazda teams shared racing information amongst themselves. The only thing that was held back was how they cooled the front brakes. Each had to figure that on thier own.

 

Update: My idle is jumping between 900 - 1000 again. At one point during a stop, my idle dropped from 900 to around 200 - 300 feeling like it was about to stall and went back to normal afterwards. I don't want to keep running the car with a single screen anymore so I'm going to put the first screen back on later. Hopefully putting it back on prevents the sudden RPM drop and isn't caused by something really serious...

 

What you are experiencing here has nothing to do with the screens. It sounds to me like your ignition coils are starting to fail. Checkand fix those and it will probably will solve the problem

 

I don't know if it's the ignition coils, I just bought them from NAPA almost a year ago and only put 8000 miles on them. I'll check though just in case, I have a two year warranty on them in case of failure.

 

thanks for reposting, i looked for the original info, and its buried...

 

sounds like a fish story that grew from a butt dyno to a ScanGauge

https://www.rx8club.com/do-yourself-...2/#post2128901

 

If not the ignition coils then it may be a combo of other things but still seriously doubt screens have anything to do with it. If MAF sensor is clean then without having the car in front of me I'm stumped.

 

Yeah, I really don't believe the coils are the issue. The car is fine as of now, no signs of idle dipping again whatsoever. I guess it's just one of those moments your MAF just gets an inaccurate reading.

 

i remove the horn n the frist screen but leave the walls. i think wall only reduce noise only but horn n frist screem removed n drop in a K&N filter it really make my 8 get better wot respond in any RPM!


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Put the horn back in. Also, the Mazda air filter isn't that bad. The K&N and Green filter will let grit past.

 

modifi your own custom make stock air box way better than waste money for no used after market intake!!!


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Hi alniesen tell me your reason of put the horn back? pleaseee! i want to read your opinion n reason! thx


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The answer is about 100 posts into the thread.
When my friend measured the difference with the scanguage, what's not important is the HP numbers. We know that HP measurements from dynos aren't exact either. That is an inexact interpretation of the signals sent from the ecu. What is important is the gain that was measured. This gain was measured with the same car on the same day within minutes of each other. The only variable being the modification itself.

 

I removed the walls and installed a revi duct. After that, the car stalls sometimes when starting it hot. Also there is some hesitation at 5000 and 7000 rpm on different gears. I have Driven it for 200 miles.

​​​Should I reset the ecu or should i do something else. The car was smooth and golden before this. No hesitation on any gear when acc. Even to 120mph. Should I just put the walls back in ?