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I understand perfectly how VTEC works.... (archive)

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Posted by Zandr on April 21, 2000 at 15:43:11:

In Reply to: You don't understand how the VTEC works... posted by Ben on April 20, 2000 at 23:29:08:

: Most people don't understand the VTEC engine.

: The VTEC engine is actually designed to get the most power over the entire powerband that it possibly can.

Nope, it's designed to go like hell at high RPM, and have "another cam" for low rpm to get some torque out of it. Stepless VANOS is closer to the "entire powerband" solution.

Look at the dyno chart it has basically two plateu's, one between 3000 rpms to 6000 rpms, and 6000 to 8500 rpms.

Precisely. One cam for high RPM HP, and one cam for low RPM torque. Single stage VANOS does about the same thing. Anyone have a dyno plot from our beloved Coupes? You'd see the same thing. (The 2000 2.8 coupes have stepless double VANOS, should be much smoother.)


: Everyone complaines about how the S2000 has no torque below 7600 rpms. Truth is it doesn't have much torqe anywhere, and thats not because of how high the rpms are. The only reason it doesn't have torque is because its a naturally aspired 2.0 litre engine. Its like the exact opposite of the old muscle car saying "theres no substitute for cubic inches." Well they've decided to substitute cubic inches in favor of light weight.

Agreed, though the low-range cam is a little pathetic. It may have been some limitation in profiles to make VTEC work, but the torque numbers on the "low" cam are comparable to noticeably smaller engines from other manufacturers.

-Zandr


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