DIY: Better Flowing Intake Box (Similar to RB Intake Box)
05-19-2012, 10:01 PM
#501
9K All Day
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.
probably going to install the airduct eventually.
05-20-2012, 07:29 AM
#502
@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.
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.
01-12-2013, 12:32 AM
#503
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.
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.
01-12-2013, 02:16 PM
#505
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)
01-12-2013, 03:02 PM
#506
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 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.
01-12-2013, 03:56 PM
#507
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!
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!
01-12-2013, 05:45 PM
#508
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^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.
01-13-2013, 11:56 AM
#511
Momentum Keeps Me Going
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
01-13-2013, 04:17 PM
#512
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.
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.
01-25-2013, 01:27 PM
#513
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...
01-26-2013, 06:14 AM
#514
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...
01-26-2013, 11:51 AM
#516
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 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.
01-26-2013, 01:20 PM
#517
sounds like a fish story that grew from a butt dyno to a ScanGauge 
https://www.rx8club.com/do-yourself-...2/#post2128901
https://www.rx8club.com/do-yourself-...2/#post2128901
01-27-2013, 06:38 AM
#518
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.
04-04-2014, 02:54 PM
#520
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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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04-05-2014, 05:19 PM
#524
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.
05-13-2017, 12:53 PM
#525
New Member
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 ?
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 ?