now dont say SEARCH because i did and i didnt find anything. . . i thoguht that vtec was 4XXX rpms . . .now i just got on my intake on my gsr and i hear it get nmuhc louder higher pitch at about 5800 5900 is that the vtec? why would an intake make that so much louder and higher pitch??

 

vtec 4400

secondary runners 5700


your hearing the secondaries open up

 

why would the secondaries be so loud? what exactly are the secondaries?

 

u have a 2 stage intake manifold. at 5700 rpms, the runners open up, allowing more air in to the motor. thats wh it gets louder

 

in a gsr there's two stages of vtec...

first stage 4400

second stage 5700

on stock - almost stock gsrs you can only hear/feel the secondary runners (stage). once you get i/h/c/e you'll feel the first stage too. if you listen closely you can probably hear somewhat of a sound change at about 4400, but i mean CLOSELY. good luck.

 

[QUOTE]in a gsr there's two stages of vtec...

first stage 4400

second stage 5700

QUOTE]

close but not quite true.

the first stage of vtec is below 4400 and the second stage is above that.
the intake is also dual stage. first is below 5600(5700?) and second stage of the intake is above that.

in an unmodified gsr u can only hear the intake switching over

 

lol!! 2 stage vtec...o man.

im gonna save yall from getting flamed as someone said that before and everybody just jumped on him.

the secondary openers are part of the intake manifold. it had nothing to do with vtec. it will still operate if your vtec is disconnected.

i know what u guys are trying to say, but others may take advantage to flame

 

the vtec is two stage, this is not hard to understand. u say the intake it dual stage low air flow, and it opens up to a second stage with more flow. the cams do the same, less air at low rpm and at 4400 the 'second stage' cam lobes r engaged and more more air is let in, not to mentiion the other fuel changes.

 

Like MaliceGSR posted above, there's no such thing as 2 stage VTEC. There's only VTEC. VTEC cam lobe engage @ ~4400RPM. The Secondary intake open @ 5750 RPM, but that's not VTEC, just intake. once VTEC engage @ ~4400 RPM, the engine stays in VTEC until redline. It's just more audible when the secondary open, that's all.

 

VTEC is 2 stages? Huh?

VTEC kicks in at 4400 RPMs considering the oil pressure is correct.

Your Secondary Runners located in your intake manifold will open up at approximately 5700. At 5700 the butterfly valve on your IM open up using short runners, which basically rams more air into your head.

 

don't answer if you don't know what the hell u are talking about, end up giving people wrong idea's...malicegsr is correct, it has nothing to do with vtec, just the intake manifold on the gsr...

 

As well as throttle position and water temp at appropriate levels.

 

if you look at it from another point of view.. then yes technically it IS two stage. one set of low cam profiles for low RPM operation and the other for high RPM use

 

Yes, but the way air enters has nothing to do with VTEC. The computer senses a point in the RPM band and switches to a more aggressive cam profile. Basically, that would just about sum it up. When the secondary runners open up, it's just another Honda trick to get the most out of the engine. Short primary runners work well at low RPM, and longer secondary ones work better up top.

edit: To make things clearer, when the secondary runners open up, this does not trigger VTEC again, nor does it switch to more aggressive cam profiles.


[Modified by dom93hatch, 8:07 PM 9/11/2002]

 

Malice is right...@ 5750..that is not ur "2nd stage" of vtec. It's ur secondary runners opening up. Or maybe you guys have two vtecz yo.

-Rod

 

I think the more appropriate way to look at it is ONE VTEC switching point (from low profile to high profile) therefore single stage VTEC.

 

Yeah on my GSR I have a cold air intake and exhaust. At around 4400 it gets a little louder, and it sounds like something is opening up. Then obviously at ~5700 RPM it gets way louder due to the secondaries

 

5th gen preludes have the secondary intake runners. Not familiar with any others