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Old 10-14-2013, 09:29 PM   #5 (permalink)
EcoModding Lurker
Join Date: May 2011
Location: Atlanta
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A bit on Atkins Cycle. Atkins cycle is where you delay the closing of the intake valve part of the way up the intake stroke. With vvti, I have the choice to use the entire stroke, or delay the closing of the intake cam until halfway up the intake stroke. This gives me two displacements and two compression ratios. Closing at the bottom, it's 1.5L and 13:1. Closing midway up it's 750cc's and 6:1. With a better ecu I could use some of the intermediate settings, say 1.3L and 8:1 or so, but for now I'm using a cheaper ecu.

Normal vvti is more to optimize cam overlap/duration. Less overlap at lower rpms and more at higher rpms. This is something that works with engine speed whereas what I need with the 1nzfxe is more based on throttle position. The idea with the 1nzfxe is to bring on the 1.5L 13:1 setting at above say 70% throttle and cruise with the 750cc setting.

With the lower comp settings, I could do FI. That's called a miller cycle engine, which is found in late 90's mazda millenias.

Yes, $200. Good condition. The reason is because Prius's don't end up in the junkyard because of their gas engines usually, and once there, the engines aren't used in anything else.

1nzfe's and 2nzfe's are a good choice for somebody not wanting to experiment like me. I'd say SZ engines would be good too, but those don't get imported into the US.
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