rjp325i said:
Finally, thanks Rukus, I've finally found someone who types worse than me. As for your physics, your all wet. You better go to the track or into engineering class and learn. I've been around for many years and your logic is abominable and very immature. You've been in the boonies too long. Its more cubic inches or litres that brings about gobs of torque. Vtec comes in and increases power across a wider rpm range. You then have higher torque in the upper rpm range and across a wider speed range. Variable cam timing can do a lot. It is a variation of BMW's Vanos as it too only works on the intakes. Double Vanos works on both. Put a Honda Civic si alongside a Honda Civic DX and the si walks away with ease.
Where did you get the nerve to come and be rude to me? i don't understand. Please clue me in on your hostility. okay?
anyways. : You then have higher torque in the upper rpm range and across a wider speed range"
is that NOT what i just said? flat torque cruve? sorry if i am wrong okay? Heres a little information to help explain what i am saying. you are more than welcome to reply with a rude comment as well.
i took this from a webpage undisclosed.
VTEC, like most things in life, is not for everyone. To decide whether VTEC is for you or not, here are the pros and cons.
Pros
The main benefit of VTEC is that the resulting engine is very versatile. The torque curve is very flat: among the flatest of all the engines on the market. Thus where other engines are running out of breath, a VTEC engine maintains a nice and steady output of torque, making the whole RPM range usable for acceleration. So when you are just driving around at a reasonable pace, the car is very smooth and fuel consumption is similar to other engines of the same displacement. When you need more power for passing, all you have to do is down shift and take advantage of the extra power available at the higher RPMs. So you get the smoothness and fuel efficiency of a small economical engine when you drive a low RPMs, and the power output of a much larger engine at high RPMs.
Due to the greater range of usable RPMs, shorter gears can be used. Thus for any given speed or engine RPM, a VTEC engine will allow for a larger ratio multiplier, resulting in more wheel torque. Thus the benefit of the VTEC technology in terms of acceleration improvement also affects low RPM operation.
Since VTEC creates more power without increasing displacement, the engine is likely to be smaller and lighter.
Cons
A vehicle achives its greatest acceleration by keeping the engine RPM as close to the HP peak as possible. And for DOHC VTEC engines, this means keeping the needle at some rather lofty RPMs, and more frequent shifts to keep the RPMs up. To some people, including yours truely, this is a desirable trait: lots of driver involvement in the process of extracting excellent performance. To others, especially those accustomed to the Kansas-flat HP curves of muscle cars, the high RPM and frequent shifts become bothersome.
For a good launch off the line, such as at the start of a drag race, a certain amount of tire spin is desired. Muscle cars have torque peaks at low RPMs, and then taper off as the RPM builds. This is perfect for drag racing as the initial torque peak generates the desired tire spin, and then the lower torque at higher RPMs allow the tire to find and maintain grip. But DOHC VTEC's torque curve is very flat, so the initial tire slip is much harder to generate. And once the tire looses traction, the flat torque curve makes it hard for the spinning wheels to find traction. So to properly launch a DOHC VTEC car, the driver must slip the clutch at high RPMs to generate the initial tire spin, and then carefully modulate the clutch and gas to regain drive wheel traction while maintaining maximum acceleration.
Even though Honda's VTEC engines has lived up to the legendary reliability of Honda products, the fact remains that having the VTEC mechanism adds complexity and cost.
anyways, if you are a "street racer" and are worried about performance, you would use a different configuration than a vtec engine and gain the same idea, but with much better results. What i mean is that a vtec engine is the same idea as forced induction, they arrange the timing of the valves to allow more fuel in, and allow higher revs, allowing more horsepower, instead of a larger engine. You might want to STILL use a vtec engine if you wanted to turbo it and that is fine. You could use ANY engine (to an extent of internals being able to handle it) But forced induction such as a turbo would be alot more desirable. Thus, the vtec is much more suitable for a daily driver than someone who wants to race.
if i were to buy a civic, i would keep the same engine, and if i were be able to turbo it, i would do that. rather than invest in a vtec, and never use its advantages.