it goes rrrrring!!! rrrrrring!!! and then "Hello, no one is availiable to take your call. Please leave your message after the tone".. and then "Beep". Yep, thats what mine sounds like :vtec::vtec::vtec::vtec::vtec:
In an effort to be helpful:
1. You have an R18, i-VTEC is actually engaged in reverse to the DOHC VTEC you're thinking of. With the LX/DX/EX, it's on at low RPMs, and off at high RPMs. This makes fuel economy go up. I'm sure you won't hear a difference, if any. In an Si, the K20 engine "switches" to it's higher cam profile, netting you more horsepower and torque. It's actually audible when you switch over, kind of like the intake pipe just got a little bigger, more resonant.
2. I don't think there's much harm in doing it. But, why not get a manual in the first place?
I can hear the crossover on my R18. It's definitely noticeable at around 5500 RPM. I don't know if it's the VTEC shutting off, like what Izzy said or what. It just becomes louder and sounds decent consistently, beginning at 5400-5800ish RPM, I forgot exactly.
"An additional version of i-VTEC was introduced on the 2006 Honda Civic's R-series four cylinder SOHC engines. This implementation uses the so-called "economy cams" on one of the two intake valves of each cylinder. The "economy cams" are designed to delay the closure of the intake valve they act upon, and are activated at low rpms and under light loads. When the "economy cams" are activated, one of the two intake valves in each cylinder closes well after the piston has started moving upwards in the compression stroke. That way, a part of the mixture that has entered the combustion chamber is forced out again, into the intake manifold. That way, the engine "emulates" a lower displacement than its actual one (its operation is also similar to an Atkinson cycle engine, with uneven compression and combustion strokes), which reduces fuel consumption and increases its efficiency. During the operation with the "economy cams", the (by-wire) throttle butterfly is kept fully open, in order to reduce pumping losses. According to Honda, this measure alone can reduce pumping losses by 16%. In higher rpms and under heavier loads, the engine switches back into its "normal cams", and it operates like a regular 4 stroke Otto cycle engine. This implementation of i-VTEC was initially introduced in the R18A1 engine found under the bonnet of the 8th generation Civic, with a displacement of 1,8lt and an output of 140Ps. Recently, another variant was released, the 2-litre R20A2 with an output of 150Ps, which powers the EUDM version of the all-new CRV"
The K20z vtec will sound meaner and more tuned (like an instrument, not like an ECU) than your R18. They both have a similar effect, more power at higher rpm through better breathing (letting more air in (with extra fuel) and out). Your best bet to hear it is on Youtube as stated previously.
I cant believe this ****, sure this guy doesn't know stuff but theres no need to mock him. I mean come on we are here to help each other and if you just mock people because they don't know certain things then its going to discourage other people from actually asking questions and learning on this site.