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OEM Airbox Modification

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Old 11-01-2004 | 06:37 AM
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OEM Airbox Modification

I pulled apart my airbox yesterday and noticed two plastic "dividers" located inside the box.

Anybody have a idea as to what they do?

Been driving around all day with the "dividers" removed and I swear the intake noise is more pronounced.

Call it a placebo effect if you want, but I also noticed abit more throttle response and a performance (acceleration) improvement.
Old 11-01-2004 | 07:22 AM
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Originally Posted by nojooc
I pulled apart my airbox yesterday and noticed two plastic "dividers" located inside the box.

Anybody have a idea as to what they do?

Been driving around all day with the "dividers" removed and I swear the intake noise is more pronounced.

Call it a placebo effect if you want, but I also noticed abit more throttle response and a performance (acceleration) improvement.
took my off a while ago when fitting the rk&n am pod filter.
there's an improve over stock, but wasnt sure whether it was the actual filter or the plastic dividers.... :o

but hey..... your photography skill's got better :D

e
Old 11-01-2004 | 01:05 PM
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so no real problems so far? i might try this today.
Old 11-02-2004 | 03:29 AM
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Two days of driving around with them removed and still no problems.

It still idles smoothly and seems to have given the 8 a "Vtec-esque" kick in the higher rev range.

The intake noise is definitely louder and more pronounced since a colleague commented on the increased noise as I pulled up to work today.

I'm starting to believe that these dividers were inserted to balance the induction noise by channelling airflow.

I urge everyone to give it a go and post your experience since I'm sure everyone will be pleased with the changed characteristics.

Worse case scenario, you can always put them back in if you don't like the "vtec" kick or the increased noise.
Old 11-02-2004 | 09:38 AM
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I just posted about this, too.

check it out
Old 11-03-2004 | 02:14 PM
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well just did this last night...man that airbox was a pain in the *** to get out the first time. would be no problem now that i know but i spent 30 minutes trying to get the top lid off. after that didn't work i found that you have to pull the whole box out and that was a breeze. just make sure you unplug everything connected to it.

then i for got to put the hose clamp back on the intake accordion hose. no big deal, just had to unscrew it all the way to get it around. didn't realize there was a little square nut on it and it ended up dropping down in the engine bay....lots of sursing now. got to spend the next 30 minutes looking for that. got lucky and it landed on the lip of a pulley.

so basically a 15 minute job took me about an hour and a half...i dont know why i am admitting to this. still getting use to working on these cars i guess!
Old 11-03-2004 | 02:45 PM
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haha.. Yeah.. that air box is hard to not only get out but also a B.. to put back in... Do you notice any differences?
Old 11-03-2004 | 05:39 PM
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i don't know if its in my head but my car seems to feel alot more "peppy". like i dsaid it would all be in my head but hey thats good enough for me!
Old 11-03-2004 | 05:50 PM
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Noojooc

May try this party trick of yours any further developments ??

cheers
michael
Old 11-03-2004 | 08:12 PM
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Still running smoothly and it seems just as responsive as day 1 with the mod.

One thing I have noticed is that I seem to get a "vtec" like kick higher up in the rev range.
This is really noticeable today since it is quite warm and humid here in Sydney.
Old 11-03-2004 | 08:19 PM
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Why not try this mod: https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/custom-built-stock-intake-pics-42631/

I think I am going to do this this weekend.
Old 11-03-2004 | 08:27 PM
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Originally Posted by Nemesis8
Why not try this mod: https://www.rx8club.com/showthread.php?t=42631

I think I am going to do this this weekend.
I quite like the look of that mod..... shame I'm too lazy to be bothered.
Will get around to it one of these days.
Old 11-03-2004 | 08:47 PM
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I tried it, i think it makes more noise, but I'm not sure. I don't notice much change in the way the car responds.
Old 11-03-2004 | 10:40 PM
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i will do this on the weekend.
Old 11-04-2004 | 08:46 AM
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It's the same thing as what we're doing, except the filter is shaped differently. You may actually have more air flow through the regular rectangular filter. Maybe not. I'm not sure, but I don't think it'd be a significant difference either way.
I agree that this mod LOOKS cool, but I don't think that there will be any performance gains over removing the slots and trumpet like we've already done. The greatest point(s) of restriction haven't changed. The intake pipe is still the main culprit. Smoothing the airflow throughout would help, as well. That flex pipe can't be the best for air flow...
Old 11-05-2004 | 12:09 PM
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awesome mod, definitly more peppy and a noticble increase in torque as i only need a 3500 cluch dump to burn em instead of 5k
Old 11-05-2004 | 12:13 PM
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Originally Posted by SaintRx8
awesome mod, definitly more peppy and a noticble increase in torque as i only need a 3500 cluch dump to burn em instead of 5k
:D :D :D
Old 11-08-2004 | 08:01 AM
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Nojooc, Sounds good (too good to be true actually). I'll give it a go too on my SP and check if there is any the difference in air mass and AFR with the Hymee CAN OBD tool.

Maybe Hymee, you could do the same on youy HP?
Old 11-17-2004 | 01:05 AM
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Stiffeners........

Those two plastic dividers are only there to stiffen the structure of the airbox, for noise control.

The hold the large top and bottom panels together, and stop them resonating with the inlet pulses. They have a soft rubber lining in the edges so they don't vibrate too.

Noise control only, no magic, nothing to see here, step away from the Butt Dyno....... :p

S
Old 11-17-2004 | 02:21 AM
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Originally Posted by StealthTL
Those two plastic dividers are only there to stiffen the structure of the airbox, for noise control.

The hold the large top and bottom panels together, and stop them resonating with the inlet pulses. They have a soft rubber lining in the edges so they don't vibrate too.

Noise control only, no magic, nothing to see here, step away from the Butt Dyno....... :p

S

:o :p :D
Old 11-17-2004 | 03:26 AM
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I'd like to see the can scan data it would be interesting.
Old 11-17-2004 | 04:23 AM
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dont wanna highjack

ok i did an intake mod i took off the black sheild or ram air inlet off the stock intake. Its right after the vtac duct. I noticed high rpms it feels peppy. i have to find a pic i have it somewhere on this website, and if not its on my comp home in Fl.
Old 11-11-2005 | 12:28 PM
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Old thread brought back but, I'm thinking on doing this, I was wondering if any of you remove one of the screens that does to the MAF. I know you need one bu this car has 2.
Old 11-11-2005 | 12:55 PM
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Originally Posted by hondasr4kids
Old thread brought back but, I'm thinking on doing this, I was wondering if any of you remove one of the screens that does to the MAF. I know you need one bu this car has 2.
I had removed one and secured the other with a dab of glue, since it was formerly secured by the trumpet. I think... it was a while ago.

I had removed those dividers and the trumpet when I had pretty much first gotten my car (~1 year ago). I had noticed a bit more noise and could then feel the change over points between the variable length intake runners. I don't think that this was a good thing... The variable length runner is designed to increase power and smoothness with very specific lengths of tubing. With that altered, it now isn't working as designed. I think that there was a slight gain in upper rpm power, since I was just allowing more air to flow more directly. So, at the end of the day, I decided to keep it as it was, with the slats and trumpet removed.
Old 11-11-2005 | 01:16 PM
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Originally Posted by RX8SpdDmn
I had removed one and secured the other with a dab of glue, since it was formerly secured by the trumpet. I think... it was a while ago.

I had removed those dividers and the trumpet when I had pretty much first gotten my car (~1 year ago). I had noticed a bit more noise and could then feel the change over points between the variable length intake runners. I don't think that this was a good thing... The variable length runner is designed to increase power and smoothness with very specific lengths of tubing. With that altered, it now isn't working as designed. I think that there was a slight gain in upper rpm power, since I was just allowing more air to flow more directly. So, at the end of the day, I decided to keep it as it was, with the slats and trumpet removed.
So, why didn't you replace the trumpet and slats if you now believe that they made it less smooth?

I had tried the turbonator and found it made a difference low end (not much) but it gave less power to the higher rpms. Didn't like that so I pulled it. So I can attest that little things make a difference but not always best.

Do you recommed pulling the plastic slats? I have the RB Ram air duct now to the stock box.


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