I recently saw a 1:30 video on YouTube of this guy taking the front half of his factory air intake box off. It caused the RX-8 to sound like it had a cold air on it. I thought about it and decided that it could probably really increase the amount of air going into my engine. Since I'm still paying off the car I don't have the cash to put into a real Cold Air. It might help my AWFUL gas mileage too? So basically my question is--> Could this be bad for my car? It seems to let me move through the gears faster and definately sounds bamf. But thats totally not worth it if it messes anything up.

Video is seen here: http://youtube.com/watch?v=rFjxWReYNUw&feature=related

Please get back to me as my car is still without the front of the intake on.

P.s. I have a K&N on there if that makes any difference.

It looks like you'll draw hot air from top (from the engine compartment), so I doubt it will do any better than stock. Aside from the sound, that is. I don't see any harm unless the filter comes loose.

You will reduce you HP.

You already have K&N so just remove 2 walls inside oem air box and bypass VFAD. You will have the same sound as CAI.

Thanks for the replies-- I worried about that engine compartment air too...

Earlier today I just removed the two walls and the bell from within the factory housing... would you suggest now putting the bottom of the factory housing back on, or just leaving it?

Would gutting the box like i did improve anything other than sound?

taking the bell out will probably lose hp - good intakes always have this feature and Mazda got this right . Taking the baffles out does nothing for hp .
Taking the front housing off will allow it to suck in hot air - reducing your hp .
at this rate you should be up to 16 sec 1/4 before you know it ..... good work :)


on a more helpfull note - there is a thread here of someone who made a pretty effective ram air duct for next to nothing - i'll find it ......


http://www.rx8club.com/showthread.php?t=147791

how exactly do you bypass the VFAD? better yet what is the VFAD

the Variable Flow Air Duct is what i think it is... its supposedly useless unless you're anal about keeping your car quiet across the rpm band

its bypassed by a cold air intake or other bought or pvc made ram induction systems

the chamber right before your intake box/air cleaner, it's an second passage way for air to flow in, when you reach certain RPM around 5k. It open's up with vacuum pressure inside your engine. Giving you more air, for higher RPM.

But when you upgrade to CAI, you no longer need it, because your fitler is postion for better air flow.

so how do you disable it?

You cant disable VFAD unless you take it all out (me)

I think he was trying to pull the extra 2 plastic inside the box to get more air *store* inside the box.

I dont think it helps anything other than increasing noise levels.

But , each to their own.

oh god that sounds horrible.

thats a bad idea!..... dude find a used CAI :) or a new one

forget it i'll just end up buying a used CAI

aight so...this myte sound stupid...go ahead and flame me..but i was just wondering since it wud suck up hot air from the engine compartnment...does it go threw the opening from where you take out the front housing?..of how there is an opening now...i was just wondering for it 2 stop scking air from the engine compartment...can you block off that gap by removing the front housing made?...but im sure since the front housing is a whole block...thats not the only place thats getting suckd air

The stock intake is quite efficient. Modifying it wil net next to nothing in HP. Possible loss of HP.
Save your money for a good CAI, AEM or Racingbeat.

from everything everyone has said you arent going to make a stock 8 any faster unless you go turbo... opinions? i aint got that knda cash if you know what i mean... alternate solutions?

Everyone! GO HERE: http://www.rx8club.com/showthread.php?t=130332

UPDATE!!! I took out the factory air intake box and removed the baffles (walls that seperate the box into thirds) and the two screens (usless airflow inhibitors that supposedly straighten flow over the MAF). Then I completely removed the front half of the airbox as shown to me in this video: http://youtube.com/watch?v=rFjxWReYNUw&feature=related. This was great and seemed to add a little power [not much at all] mostly cool sound but it began to pull hot air from the engine compartment. So I made this "custom" cover so that it would only pull "cool"er air from outside.

Thoughts? Think my problem is sloved or that this is a good idea? Opinions please...

Sound good, untill I saw duct tape.

Everyone! GO HERE: http://www.rx8club.com/showthread.php?t=130332

^ :)

renesis dont be a dick... and yeah the duct tape is REALLY redneck-- sorry but i was scared the metal plate would heat up in the engine and thus heat the air under teh plate.... so i used all i had available

know where i can get heat wraps or heat tape?

UPDATE!!! I took out the factory air intake box and removed the baffles (walls that seperate the box into thirds) and the two screens (usless airflow inhibitors that supposedly straighten flow over the MAF). Then I completely removed the front half of the airbox as shown to me in this video: http://youtube.com/watch?v=rFjxWReYNUw&feature=related. This was great and seemed to add a little power [not much at all] mostly cool sound but it began to pull hot air from the engine compartment. So I made this "custom" cover so that it would only pull "cool"er air from outside.

Thoughts? Think my problem is sloved or that this is a good idea? Opinions please...

It still looks like that slit opening pulls from the engine compartment. My guess is louder sound but less HP. Each mesh screen only drops 1 HP and really does smooth air flow over the MAF. Some get away with 1, but with none, you're likely to have issues with idle or even stalling. Your hot air getting pulled from the top may exacerbate that.

If you haven't read Racing Beat's FAQ on their REVi intake, it's worthwhile to better filter through the speculative info on intake mods. http://www.racingbeat.com/FRmazda4.htm

For heat wrap, places like JEGS sell the real stuff. You can get wrap that has an aluminum face and an adhesive foam base from the AC/heating section of Home Depot/Lowes. I don't think the heat there is too much for that. I used on my center console. I have one of Roar Racing's old RB intakes and they wrapped everything but the top and front. They even had wrap on the MAF tube. I left it all on. Not pretty, but they thought it helped temps.

well before i took the front of the intake off i did the first baffle and screen remove and everything was perfectly fine. Once I did that i then took the front off and added that metal top peice which i carefully measured to meet with the hood at the front so i dont think its pulling hot air. Though you are right-- i dont stall but i get an idling tremor once every 3-5seconds. I reset the two ecus (brake and odo methods) and just need to drive it and see if the car can learn it or not.

I'm in destin so ill post the results when i get back next sunday or monday

oh god that sounds horrible.

Don't knock it unless you're tried it yourself...that guy's 3 second clip at the end of the recording hardly does the sound justice. I took a stab at it myself and it sounds pretty wicked if you ask me. On the road, the loss in HP/TQ is minimal compared to the kind of sound feedback you get back in return. What I especially love is that you can VERY clearly hear the secondary intake ports opening up right at 4000 RPMs now after this mod...the sudden aggressive "opening up" transition in sound is awesome. Reminds me of back when I sat in my friend's Celica and hearing the lift kick in at high RPMs. The end result is definitely loud, but still sounds much better dampened and lacks the tin can-like vibrations that you get with some of the aftermarket intakes that use a lot of sheet metal.

The sound potential of the stock intake amazes me everytime I remove yet another piece of it...I definitely don't need an aftermarket intake for more sound after this!

http://www.youtube.com/watch?v=Qx3iCkKw2eA

okay so..that was my idea and im gessing it can do justice...anyway....yea...i doo feel less horse power with the front taken off in 5 and 6 gear but 1 2 and 3 u can feel a lil bit more

yet another update... heres a picture of the in take without baffles or screens... i had to put one screen back in because the idle had a tremor without but you definately dont need the second one (try blowing through just one screen onto your palm-- they REALLY restrict airflow)

the other two are of the sheet metal i reshaped and covered with insulation tape good for -35 to 260 degrees

i added a front to it so it wouldnt pull hot air from the engine compartment

i can feel a very very slight power gain and it sounds WAY cooler now

heres the other pic... sorry it didnt load the first time

anyupdatE?

sound as reported by me, my friends, and coworkers kicks ass

there is no loss in power but no gain either

idling and driving are fine

if you want a completely free cool sound on your exhaust go for it

i left it like it is :)

If you really want to cool the air box you need to cover the bottom and sides with insulation.

Definitely a ricer mod.. its like getting that ebay turbo sound thing.. either way you slice it it does nothing.

renesis dont be a dick...
And talking to seniority members like that gets you nowhere when he is trying to get you to do it the right way, Its just Ignorance.

wind,

to say the truth... i actually took out my nice RB air duct because it gets my K&N filter dirty too fast. and a dirty filter is not a good performing one.
i ended up even reinstalling the vfad back on.

if vfad is left off... it can also make some noise. just in front of the car...

i guess my point is, to each his/her own. and at this point, by moving the front noise level to the engine bay more, he would have to hack up the box rendering it useless for sale. but he achieved what he wanted.

maybe its a reversible mod, maybe not. i'm sure he's aware what he's doing... and if his regrets comes later in life... well, we all learn somewhere.

i take hot rodding with a different approach. and i prefer function over form... but take in reversibility in mind. and the mods to make permanent/keep on would have to be of oem equivalent or better.

that being said, to the OP jea...

a simple vfad would've yielded likeable results w/o ruining other parameters.

leave the stock box system alone... look up other air box mod threads... they should be quite similar.

i've
-smoothened/polished the TB
-baffle plate removal
-blocked off the resonance chamber
-inserted a 3.5inX3in sleeve over the accordian flex pipe

all on a stock intake system. but i have no noise gratification to enjoy.... just the actual work done to enjoy.

i'm happy with it. and happy to have shared it with others. and to others who'd missed one step in what i've done, are welcome to do it to theirs if they feel an urge for a stealth and simple approach.

^ True but then like everyones trials and error proves that from the factory without any other MAJOR mods, the stock intake is tuned to flows MORE than enough air the rennie can actually handle. Messing with it does nothing.
Messing with the vfad is another subject.

BTW did you have the air duct on stock intake? How was it.. besides the extra bugs.. lol Oh where did you get your 3.5" x 3 pipe. Only place I've seen it was pepboys for freaking $30.. insane for a pipe.

^^seen them at superautobacs for something like that.
went to an pipe supply shop looking for a aluminum piece... it costs a pretty penny as well, plus the fee to cut it? and the gauge is rather thick.

BUT!, needing something at the neighborhood homedepot... i came across a perfectly sized styrene coupling for 79cents in the plumbing section. i picked it up and simply filed down the center section where the joining pipes would meet.

sure its plastic (or "styrene") but it does the job.and the pipe needed to be shortened 2-3mm in order to be removed/fitted in between the airbox.

as for how i filled the resonance chamber? i simply jammed any bottle cap (brake fluid) in the hole, glued it tight in there and sealed it up and re-insert.

as for the air duct... well it got things dirty. and its not like i got a nice induction noise when coupled with the stock airbox.

and i personally enjoy a light engine/full stainless catback noise singing in harmony. and i think i can stayed satisfied with the stock box/vfad/catback combo.... as well as keeping the filter cleaner and running optimum longer in the process.

not saying its the best set-up. its one I can deal with.

Wow seems like you went beyond the simple hacking of the airbox... lol
Very creative at that.. i wanted to try the air duct, but not a big believer..

Ok wind if you wanna get some wonderful message into my stupid little head I'd suggest a more controlled approach. See I respect Magic because while he disagreed he didnt try to be offensive, he just provided a counter-point and what was basically (or definately lol) a better idea/way of doing the exact same thing.

Don't put it down as having no gains when I said that up front. Don't put it down as "ricer" when you havent done and heard it yourself. I wanted an EASILY reversible mod that wouldnt HURT my car, would be FREE, and be fun to do with maybe a cool sound gain. I got it. Thats what I wanted. Thats what i told everyone it was.

Also I don't know know where you think kissing renesis' ass is going to get you-- this is an online forum hahaha.

But long story short... Thanks for your input Magic... when I have the extra cash and confidence in my noobish abilities ill definately look into what you did.
As for wind, I dont respect you at all. I love watching idiots like you try and be bamf on online forums.

As for wind, I dont respect you at all. I love watching idiots like you try and be bamf on online forums.

Like you stated this is a forum, nowhere have i asked for your respect. So what was the purpose of all this and wasting away a thread?? For some noise.. Congrats:lol: