Quote Originally Posted by voltscastillo View Post
vtec-e just cracks open one of the valves that deliver fuel into the engine. thats why it's called vtec-e (vtec-economy) so that design allows for a very lean burn at low RPM situations, like idle and traffic. so in principle, the vtec e mechanism is already engaged at low RPM.

higher RPM allows all valves to open to allow max fuel and air. at this point, it runs like a normal engine at high RPM. vtec-e disengaged. at least, this is my understanding of how it all works - i could be wrong.

i've no idea if it switches to a more aggressive cam profile like the B16s. if it does, i don't feel/hear it, bro. and i almost never run any of my engines to 5000 RPM - baka masira lang at mabilis na yun at highway. 3500 RPM yata and i'm already running at 125++, and i sure wouldn't run to 150 on a stock car with pathetic econo tyres...

older vtecs make a distinct (but rather faint if you dont pay attention and the car's not set up) woooooo sound at vtec. this is my experience, riding shotgun with a friend who owns another vtec. others say its waaaaaa, and with camgears, it's wooooooo WAAAAH! daw at max throttle. i guess it's a diff sound for everybody.

most vtecs aren't like turbos that sort of lag then boost then suddenly kick... unless it's tuned to do so. vtec is there to allow you to exploit all the horses of the engine at higher speeds, so you still make power all the way to the redline. that's why they're so fast, i guess... lapit na redline pero kaya pa humatak.

AFAIK the 2001-2005 Civics have Vtec-3 engines, according to the sticker at the rear windshield. And napansin ko nga rin na if you floor the gas, when the rpm reaches somewhere near 2500rpm, biglang lalakas yung hatak, then somewhere 3500+ lalakas bigla yung hatak even more, and at about 5000+ bigla ulit lalakas yung hatak and parang full power nya is near redline.

I've read before somewhere na Vtec engines are high-rev engines, where their power is at the peak somewhere in the high revs like 5000+, and the low rpms is where its power is least. unline the Lancer daw which is a low rev engine so malakas ang hatak at low revs, and kung at high revs na, hirap na humatak. Also sa Nissan napansin ko, sa low revs, malakas ang hatak, and when you rev it higher, humihina ang hatak, baliktad nung sa Civic namin.

Maybe thats why matipid, during normal driving, you dont really need to rev high, thus not much power is needed. Sa other cars, malakas siguro ang FC kasi during normal driving at low revs, nandun yung power so malakas rin ang need for fuel. Well thats what i think.

I like our 1.6 Vtec 3 being able to outrun 2.0L cars when needed, yet consuming fuel like a 1.3 car when driving normally.