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Old 11-09-2014, 04:45 PM   #29 (permalink)
Ecky
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Join Date: Dec 2011
Location: New Zealand
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ND Miata - '15 Mazda MX-5 Special Package
90 day: 39.72 mpg (US)

Oxygen Blue - '00 Honda Insight
90 day: 54.69 mpg (US)
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Quote:
Originally Posted by undeRGRound View Post
Good overall Cam Swap posting! Nice site. MetroMPG!

The only thing here I see that makes an incorrect assertion is where it is stated that "the smaller lift and duration" is what makes the lower RPM cylinder pressure and torque increase. Generally, it has been found that higher lift will increase torque and HP without losing any low-RPM torque, and sometimes below-peak torque is also enhanced.

I'd like to think I could get a custom regrind based on a regular 3 cylinder cam that could handily beat an XFI cam in MPG, Torque AND Horsepower, but the HP might take internal engine mods. OEM engines are so far from optimized that a dedicated builder can easily make all aspects better with a little hard work and research. A great book (now out of print) Practical Gas Flow, by Dalton.

There is ONE Outstanding cam spec that determines engine responsiveness, torque and HP more than any other, can anyone guess what that is?

Lift?

Duration?

Ramp Rate?

Lobe Style?

...or something else?

I'm not too terribly informed about cam profiles, but lower lift duration should (to a point) move peak torque lower in the RPM band, where almost everyone on this site drives, right?



Also, I'm willing to bet there isn't a better cam that could be made for my car. It seems Honda gave their engineers leave to go all-out for the first-gen Insight.

EDIT: Welcome to the forum!
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