Scion tC Forums banner
1 - 20 of 25 Posts

·
Registered
Joined
·
498 Posts
Discussion Starter · #1 ·
What the heck is that thingy, I think it whistles at 3000 rpm......


 

·
Registered
Joined
·
11,881 Posts
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.
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Registered
Joined
·
11,881 Posts
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*
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Registered
Joined
·
171 Posts
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.
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Registered
Joined
·
224 Posts
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?
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Registered
Joined
·
224 Posts
So one more time, is there any purpose in removing the resonator box then?
 

·
Former '05er
Joined
·
12,467 Posts
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.
 

·
Registered
Joined
·
224 Posts
Oh I see, Thanks for the explanation Lo Bux
 

·
Ironhead
Joined
·
13,253 Posts
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.
 
1 - 20 of 25 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top