Drop some I-vtec knowledge
Push to shock!
Joined: Sep 2002
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From: Palo Alto, CA
I'm not saying i-VTEC doesn't help, I'm saying that the dominant factor is displacement, not intake timing. Also, the engines I'm pointing to with large gains over stock intakes are all 2.5 L or above. I'd also say that a K20 without i-VTEC would probably still have more gains than an F20 because it runs at higher RPM's, so it demands more air and has more benefits from an intake.
Senior Member
Joined: Jun 2002
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From: montgomery alabama
Originally Posted by Kestrel
I'm not saying i-VTEC doesn't help, I'm saying that the dominant factor is displacement, not intake timing. Also, the engines I'm pointing to with large gains over stock intakes are all 2.5 L or above. I'd also say that a K20 without i-VTEC would probably still have more gains than an F20 because it runs at higher RPM's, so it demands more air and has more benefits from an intake.
Push to shock!
Joined: Sep 2002
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From: Palo Alto, CA
Yes I agree that i-VTEC helps with gains. So yes, I agree that a K20 gains more than a B20 or a B18. But, the gains are less than what you would get for, say, a 3.5 L V8, or 2.5 L flat four, or any large displacement engine. Why? Because those engines suck in lots more air, and as a result, they are more restricted stock than Hondas are. So they stand to gain more from aftermarket intakes and exhausts. The point being, then, that displacement plays a larger role than timing.
HIDs teh hotness!
Joined: Dec 2002
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From: Newnan, Ga
I have it explained on my site under the basics section, http://www.honda-fanatic.com or u can go to http://asia.vtec.net/article/ivtec/ they have the info too
KiMBO's Hubby
Joined: Mar 2002
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From: San Hose Jose
Originally Posted by YeaItsAFourDoor
So Ivtec is Vtec and VTC combined? Oil pressure of course is what helps start it but I-vtec is the advancement and retardation of the intake cam to adjust overlay and such for fuel economy and power along the band? Vtec is just the oil pressure causing a different set of cams to open and close the valves faster and long and VTC is the variable cam timing? Please correct me if im wrong...
2: once open, the oil pressure is high enough to push the locking pin and engage the rocker arms related to the VTEC cam profiles.
3: the cams are a solid piece of metal that does not move vertically or horizontally, it just spins. the profiles of the cams (aka cam lobes) pushes down on the rocker arms, which pushes down on your valves.
4: the VTEC cams have two different profiles on them: one for non-vtec and the other for vtec. these are always spinning together and pushing on the rocker arms. the vtec rocker arms are not pushing down on the valves until the locking pin is engaged.
5: iVTEC has a better ability to control ignition timing. this has nothing to do with cams and its profile. the retarding and advancing is just when the spark actually ignites the fuel mixture. retarding means the spark ignites the mixture after the factory adjustments, advancing means the spark ignites before the factory adjustments