jea1989

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.

G-ReX

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.

Razz1

You will reduce you HP.

krijpipudht

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.

jea1989

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?

Brettus

iTrader: (2)

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 ......


https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/cheap-ram-air-147791/

M52Cat

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

jea1989

the Variable Flow Air Duct is what i think it is... its supposedly useless unless you're **** 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

Silver_Mazda09

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.

M52Cat

so how do you disable it?

nycgps

iTrader: (1)

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.

kersh4w

iTrader: (3)

oh god that sounds horrible.

lepichichi

iTrader: (10)

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

M52Cat

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

flipRx8

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

Easy_E1

iTrader: (2)

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.

jea1989

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?

Spinning Sushi

iTrader: (21)

Everyone! GO HERE: https://www.rx8club.com/series-i-do-yourself-forum-73/diy-better-flowing-intake-box-similar-rb-intake-box-130332/

jea1989

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...

krijpipudht

Sound good, untill I saw duct tape.

Spinning Sushi

iTrader: (21)

^

jea1989

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?

G-ReX

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.

jea1989

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

Vertigo-1

iTrader: (3)

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