Spark explaining how VTEC works.

[SO•Audiojack]

(2015-09-13 20:02)Johan. Wrote:  

(2015-09-13 17:50)Yukine Wrote:  Professor Spark.

If I understand your explanation, a VTEC as a build-in ECO mode?

Yes they once developed it to get similar power on higher RPM whilst keeping a low fuel useage, my guess is that the rest started from there.

AJ is our Honda expert though, maybe he'll chip in soon.

They have just generally improved the performance of their engines by keeping the optimum valve lift through the rev range. This improves both fuel economy and performance. Neither part is really a "by-product" The system is just great like that.

You guys probably know that you can replace or grind your camshafts to ones with a more aggressive profile and lift in pretty much any remotely modern engine. This affects a lot of things but basically what you get is more fuel in your cylinders, which is bad for fuel economy but good for high revs and maximum power output.

So what Honda did is basically they just put more lobes on their cams and just change which ones they use with a pin mechanism. So now they have the regular cam and the aggressive performance cam in one.