Hey guys,

Do any of y'all experience the drastic change in the sound from the CAI above 5000 rpm?

From 2500-5000 it is sucking air like crazy and then as soon as I hit 5000 rpm, it is like the motor is pulling too much air for the filter and it goes quiet.

Obviously, the car still pulls great at this range but I was just wondering if any of you experience the same thing.

I have an 07 Type-S; Fujita 5, Stage III Exhaust

 

vtec engages at 4950rpm this could be the sound you are hearing when it crosses to the the high cam. The engine gets louder so maybe thats why you dont hear as much of the "sucking sound".

 

I LOVE the sucking sound!!! :gheywave:

 

I knew v-tec engages at that point, but it's strange.

Only thing I can guess is that at that point, when v-tec engages, the motor is pulling more air and meets the maximum allowable flow rate for the filter/tube setup. The suction sound is a result of low pressue in the tube. Maybe at this point the amount of air coming through the filter is equal to the amount of air coming into the motor.

Who knows... I'm a mechanical engineer and tend to overthing these things.

 

Or maybe it's the butterfly only open part way, which makes a louder sucking noise than a fully opened butterfly.... Just throwin it out there.

BTW... I highly doubt that you'll ever get to the maximum CFM's allowable by the CAI, even with a turbo or supercharger.

 

The "amount of air coming through the filter" is *always* equal to "the amount of air coming into the motor". It's a closed system for all practical purposes. Every full cylinder cycle intakes ~3.5L of air. Think vacuum pump.

With regard to cfm, maybe as rpm's increase you are right - the velocity inside the tube changes (increases) to feed the vacuum pump (engine) a constant 3.5L supply per full cycle. At ~5,000 rpm, maybe the increased velocity creates sound as a result of turbulance or something along those lines.

I have exactly the same set up and I think the change in tone you hear is VTEC and the "roar" from the CAI tube.

 

vTAK GOES BAWWWWWw!11!

 

VTECH just kicked in yo!!

 

haa i was just about to say that

 

I dunno I love the CAI sound(the air going through a straw sound)........sounds like a mini turbo haha

 

vtec

 

it can't be v-tech guys.. unless you're a 6mt and even then u'd barely notice it..

remember, it's a SOHC =( ... why on the TL? Honda, whyY?

 

In my 99' TL the intake roars at v-TEC.

In my 08' TL not so much. Same intake AEM Dryflow.

Not so sure why to be honest. I only hear it slightly once vtec kicks in on the 08. The 99' sounds like it has a straightpipe and no mufflers. lol

 

or a wolf getting f'd ahhh ... i can't steal his line... i'll let him come in here and chime in...

 

darksom1 where r u! muahahaha

 

why oh why is vtec only at 5k rpm WHYYYYYY? haha

 

hey when someone has a stage 3 in theyre sig what is that? resonator stage 3?

 

Its referring to different stages of exhaust modification. Stage 3 means that they removed the mid muffler and replaced it with straight pipe and then swapped the stock resonator with a dynomax resonator.

There is a thread that spells out what all the stages are, you just gotta search for it.

 

gotcha thanks