The noise could be vfad related ...

Try diconnecting the vac line to the vfad and see if thaT CHANGES ANYTHING .

 

We read all the forums before buying one, she redlines it at least once a day after it is up to temp, and she rarely ever drives it in AT mode.

I just went out, did an ECU reset and checked the intake/ airbox. There is nothing that can be flapping, and it is not resonance. I know for a fact that it is going to make the same noise just quieter, once the intake is back to stock. After doing the ECU reset and checkover, i made an attempt to get it real hot. The car got to the point where it had little power, made the noise even as low as first gear and 4500 rpm. It sounds incredibly thrashy. It had a loping idle, and was making an odd quiet sqeaking noise. I let it cool down for 10 minutes, and went out for a 3000-4000 rpm highway drive to get some air through it again... The idle came back to normal, the squeak went away, yet it still made the noise. And last night we were able to get the noise to go away completely... Hmm.

I dont have a stock lower half of the airbox to put on right now, or I would. However, I can almost guarantee it is not that problem.

This is driving me nuts, and now she wants to trade it in for a Miata. I feel bad for getting her into a car which is having odd problems.

 

And obviously plug it at either end correct? Should I leave the electrical plug on the VFAD control which is mounted on the airbox plugged in?

 

All you would need to do is disconnect the vac line for the VFAD, behind the throttle body, and cap the fitting.
Then tie the hose off to the side so its not dangling around in the engine bay.
The electrical connection for the solenoid can stay in place.

Just to let you know... by doing this you are allowing the VFAD valve to stay open at all times, so the car will sound louder at lower RPMs.
But it won't harm anything.

 

i'm not too worried about the sound.

When installing an AEM/ K&N/ etc. intake you would have to do this anyways, correct?

I'm going to try this, and will report back in 20 mins.

 

Yes... you cap the nipple behind the throttle body also.
But for you, there is no need to remove the hose... just tie it off to the side so its not dangling.

 

Also - someone suggested it could be the panels in the airbox vibrating . Check this as well by removing them .

 

You think its better to shove a screw in the hose instead of simply capping the nipple behind the throttle body?

 

/\ if you have the right cap - no . Who has a cap like that on hand though ?

 

LOL... I guess some people may not know you can get a variety pack of vacuum caps for a couple dollars at Autozone

 

heh - correct

 

Capped the VFAD line and removed the panels from the airbox. no dice, same result.

The only things I have not done yet are new plugs/ OEM bottom half of the airbox, for the simple reason that I do not have them.

I notice that the engine bay is crazy smokin hot, I know rotaries run hot.. But i mean this is hot. The coolant temp guage reads normal.

 

WoW!?!?!?!?!

As started go back to stock and see what happens. Mazda designed the 8 airbox very very well and I can not understand why you would take the VW guys methods into consideration. If your looking for sound then buy a RB or AEM intake new or used in the for sale section (Intakes are available a lot). But before you do anything go back to the stock set up.

One thing you might want to remember is that Mazda designed almost very component on the 8 very well. So well that it's a bitch to gain Hp with simple bolt-ons. Gaining more then 10+ in terms of Hp or Tq is almost impossible without going FI. Sound will not make the car go faster. You have to pay to play , there are no short cuts.

Hope you learn from this mistake. Good Luck

 

Just went for another drive at higher speeds trying to get some air through the front of the car. It would only keep making the noise, and with the panels in the airbox out... It has never been thrashier.

At this point I give up. We'll be looking for a stock bottomhalf of the airbox for the car, and she'll just have to live with the fact that it does not make as much intake noise.

Her brother is a mechanic, and we're going to get him to do the airbox/ plug the VAFD back in/ plugs/ oilchange/ and rear diff fluid change as the LSD is chattering under low speed parking lot cornering.

As previously stated, with the intake we were looking to gain no power.. Only sound. If mazda designed the car so well, why could'nt they get it to make some real power while getting V8 fuel mileage.

I guess thats why it's her car, and my wagon has a turbo. Thanks for the help guys, if you have any other ideas.. I'll be inclined to hear them out.

 

Oh Boy.......................... I'm not going to touch that remark I'll let someone else do it LoL

Oh, and before you go have some else work on the the car look at the DIY and printout the info you need to do the repair the right way the first time. Better yet you should try to buddy up with some of the guys in your area that have knowledge in the 8.
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So then you should have done your homework and read through the threads on this site to achieve that.
Plugging the VFAD fitting to keep the valve open at all times is one way to achieve that.
Another is to remove the resonance chamber and plug the opening.

Because a "well designed car" isn't always about HP... only teenagers and people who jerk off to the "Fast and the Furious" movies think that way.
Take the RX8 to an auto-cross event or down some windy roads and you'll understand why the RX8 is in fact a well designed car.

And this is also why the whole intake setup is so complex with SSV, VFAD, APV, and VDI valves.
Because Mazda tried to get as much out as possible from this little 1.3L engine while still complying to federal regulations.

 

^

 

sorry guys.. Did'nt mean to offend any of you. It is a fantastic car down a windy road I will agree. Engine and exhaust wise it is stock, cass just wanted some sound out of it so I made it a sri. Worked well on my ms3 until I ordered all my corksport goodies.

 

I'm not offended because you're entitled to your own opinion, just didn't want your views on "well designed cars" to be skewed and limited to one category.
Most people here are fine with admitting that our car isn't made for the drag strip, but unfortunately we are constantly paraded by individuals who want to turn it into a "drag car" with minimal effort, money, and experience.

Best thing you can do is what I mentioned above, an aftermarket intake like the AEM or Racing Beat, and/or aftermarket exhaust setup.

 

There was a theory thrown around a while back that the squeaking noise you describe may be a sign of a bad coil. I haven't read of any verification of this but as I re-read through your posts, it seems to me you may have a classic "weak coil" situation and you are certainly within the mileage range where it is rather common for coil failures.

I do not want you to buy anything, especially something as expensive as our coil kit, on a mere hunch as you may have a few concurrent problems. At the same time, we do know that the BHR Ignition System is a definite improvement over even brand-new OEM coils so if it is something easily affordable, you may want to place it at the top of your list when the current issues are resolved or bad coils are shown to be the cause.

Tell her to hang in there and we will all sort this out so she can resume enjoying her RX-8.

 

Hi Charles. I have seen your BHR Ignition system before. Can you briefly describe the benefits over the OEM?

 

http://blackhaloracing.com/products-...tion-system19/

 

You should have called me .....I'm sure I've got one around here....I have all my RX8 and MX5 OEM removed parts.

 

Brian, I'll be in touch... Once I can find your phone number again. I changed phones and lost all my contacts.

Thanks for the help gents, i'll let you know the airbox related outcome.

 

Out of cursiousity, the diff is starting to chatter under low speed cornering too. Parking lot sort of setting..

I imagine the diff uses 75w90, which I have already.. How much friction modifier should it see? The car is the GT (CDN car), so it has the LSD and good stuff from the factory.

Or with 38,000 km... Should I just add a little more FM to make the chatter go away.

Plugs will be done tonight by me. I had Cass call the dealer and we forwarded Larry the Service manager the Youtube videos. He figures its plugs. After I change plugs, and everything is back to OE the only other thing to do is take it in and have them work with it if the car does not co-operate.

FWIW - Incase someone else has monkey'd with the car before us. What is the correct Coil to Plug wire combination. I've read that the trailings can be backwards and it'll still run, only poorly. True?

Thanks again, and Brian I'll give you a shout after work.