obeytheflag

im going to ask a very n00b question but hey where else am i gonna know? what is the purpose of the resonater tube (i think thats wut its called, that black plastic tube that is above the radiator) I think its used mainly to muffle the engine sound but i am not sure.

obeytheflag

i realized its not called the resonater tube, i don't know wut it is called but i know its part of the intake system

Davard

Before Edwin says "Check the FAQ"...

It's called a Helmholtz resonator. Besides providing air for the Idle control circuit (that's the small hose under on the bottom). But it's primary purpose is to damp the pressure wave that runs back up the intake tract when the intake valves shut. It also works when the throttle slams closed in a similar way.

What happens when you take it out. You lose 5 ft.lbs of torque in the low-to-mid-range. With no HP benefits. Call it a no-brainer.

protegeDX

wow so everyone putting in cone filters and taking those out is losing power !@$!@$!@$

kagekun

yea, so, basically isnt a cone worthless?

protegeDX

so why not have a cone, seems to suck in more air AND have that thing that goes over ur radiator =D

Gene

I would think the cone filter would benefit a high rpm car like a drag car and the resonator would be beneficial to cars that operated in the mid-rpm range a lot like a Auto-X car.

For a mild street car I would keep the resonator.

JMO as I don't even own one of these cars yet.

mazdaspeedwest

pretty sure he was refering to the tube that goes arcross the engine just above the radiator, as this is a muffler, so to speak. also it's in a place that can heat the air...not a good thing.

the Hbox is a good thing, i removed mine for a while and found great top end, but low end suffered, bogging out of tight corners. It's back on now and it feels much better.

When you add a cone filter, the runner (muffler) tube is removed with the rest of the OEM air box labrynth but the HBox is not.

Davard

Yeah, rereading the first post, that is what he was talking about. It's just a resonator to damp the sound of the intake. Only thing you'll get removing it is more (some?) intake noise...and warmer air if you don't block of the opening or redirect the hose.

But I did forget to mention another reason that you lose power at low-mid rpm is that the pressure wave pushes against the back to the VAF plate, restricting flow and making the ECU see less air.

protegeDX

oh yeh. haha i forgot that the piece on top of the radiator goes into the HBOX. kept thinkin it went in the maf for someone reason. someone slap me. anywayzzzz.. my friend told me to make the hole on the HBOX bigger for more air cuz the box is good for low-midrage.

mazdaspeedwest

well, actually it goes into the airbox, not the Hbox

JAC

So getting an AEM/CAI actually reduces power???

protegeDX

yah intakes reeduce torque but ups a little horsepower. i believe its like this, when u gain torque u lose hp, when u gain hp u lose torque. but not in all cases its just what one of my friends told me.

Davard

Not all mods are like that. The Pacesetter header actually seems to make both more torque starting at about 3k rpms, without falling off above 6k like the stock manifold. There seems to be no loss below 3k either.

The problem with a CAI (compared to the stock intake) is that the flow velocity at low rpm isn't high enough to prevent pressure wave reversion that occurs at low rpm. In addition, removing the H-box makes this worse. So, while you might gain 5 hp above 6k rpms, you'd lose 5hp below 3k. Bigger piping makes this worse, with 2.5" being about optimum.