[fiream]

What the heck is that thingy, I think it whistles at 3000 rpm......

 

[Obike]

That's just a air resonator box... it doesn't really do anything except make the engine quieter really.

And the whistling sound you hear is actually the cams, almost all Toyotas make that "whistling" sound.

 

[lo bux racer]

The cams? Who told you that? Cams can't whistle. If they do you have a serious oiling problem and the engine isn't long for this world.

 

[Obike]

Originally posted by lo bux racer@Sep 5 2005, 09:46 PM
The cams? Who told you that? Cams can't whistle. If they do you have a serious oiling problem and the engine isn't long for this world.

Several WRX, Honda, and Toyota enthusiasts actually... I first believed them to be the valve's but *shrug*

 

[lo bux racer]

They don't know what they're talking about. Whistling is a caused by air moving through the intake. Throttlebodies can whistle very nicely. If you'd worked on carburetted engines, you'd have heard this yourself. Certain geometries in an intake will cause whistling, although most manufacturers try to minimize this to meet Federal noise standards.

DOHC engines don't make much cam noise of any kind, especially when the adjustment is built into the bucket as is the 2AZ. The noisiest thing in a DOHC engine is the cam drive, not the cams.

 

[peglegskier]

i've been wondering about that box forever... i could only assume it was a sound deadening device. it has no hoses or wires going in/out... it's just a tumor on the intake

 

[Hudnut]

Originally posted by Obike@Sep 5 2005, 08:37 PM
That's just a air resonator box... it doesn't really do anything except make the engine quieter really.

And the whistling sound you hear is actually the cams, almost all Toyotas make that "whistling" sound.

Actually, resonance can effect performance. Mazda/ford used a variable resonance intake system (VRIS) on the KL-xx engines. I think porche used a similar setup at one time.

 

[lo bux racer]

Usually the variable systems have some kind of valve to actuate them. The one on our cars is likely for noise reduction. I removed mine sometime ago and have noticed no difference in performance. Admittedly, I haven't done any timed tests to see if there is a small difference or not, but I know for sure that box acts as a heat sink, that's why I didn't want it on my car.

 

[Ryan'stc]

what benefits can be achieved by removing it Lance? And how would you remove it without creating a large hole?

 

[lo bux racer]

Dr. Isotope posted about this a long time ago. He took his off after seeing heat soak sitting at idle (like a red light) that took awhile to go away. I asked him about it, he said he just plugged the hole.

So I was rooting through my toolbox looking for something else, and discovered a 2" rubber stopper (I don't even remember where I got it) that just happened to fit in the hole. I used a conventional hose clamp on it, and I've been without ever since. Actually, I had two stoppers, D has one on his car too now.

 

[Ryan'stc]

So this won't void my warranty or anything will it? I'm guessing I can go to home depot to get the part.

 

[Dr. Isotope]

Yep, I sure did. Rubber pipe cap, any Home Depot, about $2.

I even sanded the "Oatey Test Plug" letters off the end for extra sleeper factor.

 

[Ryan'stc]

Wow that engine cover looks really nice Isotope.

 

[Hudnut]

There's my new plug. It may not be as "sleeper" as the Oatey Test Plug, but the hunter orange is all the bling. FYI it's a shipping plug for the tailhousing of a trans.

 

[BlackTC]

Sorry if this has already been covered, but after removing the resonator box and covering it, do you get a change in the sound? In other words does your car get louder?

 

[lo bux racer]

I didn't notice anything, but I rarely drive with the windows down. Typically I need to have them down to really notice any change.

 

[BlackTC]

So one more time, is there any purpose in removing the resonator box then?

 

[lo bux racer]

Yes, it adds heat to the intake air when you sit at a traffic light, so you get warm air when you need cold the most.

 

[BlackTC]

Oh I see, Thanks for the explanation Lo Bux

 

[iGod]

ah yes, one of the rare occassions stuffing a plug in a hole wont actually RAISE the temperature.

dont go there.

i havent noticed any noise increase, so if it is there, it isnt noticeable for me. my hearing isnt spot on like a decibel meter, but sonar techs have pretty good hearing. i would say it's no louder.