Quote:
Originally Posted by Kaotic Lazagna
I actually never heard of it until I started working at a Toyota dealership. lol. Kinda don't like how you lose torque tho (not sure how the torque curve is affected).
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"Lose"
It's a negligible loss (2 ft-lb), and the very low rpm torque is definitely better (I'm saying this without having seen a dyno chart though). The reason is because Valvematic starts with a higher duration cam and cuts duration and lift together. The non-Valvematic engines have fixed cam profiles that's a compromise between low end and top end, which performs very strong in the midrange.
The Valvematic engine had higher horsepower because at high rpm it uses the full lift profile of the cam, but at lower rpm the optimal duration is lower, and the only way to get lower duration is to also lose lift.
The plus is that at low engine speeds, the Valvematic engine should have lower lift, which will help combustion by speeding up the intake charge, producing more torque, possibly.