very informative graphs

[koji_kabuto]

SOURCE: Adapted from Amann (1991).



SOURCE: Adapted from Ford Motor Company (1991). but this section explains the vtec-e homo/stratified charge.

Automotive Fuel Economy: How Far Can We Go?

i had this paperback for free ages ago yet i forgot to share it. being naive i dont know if anyone has this

[theholycow]

What a coincidence! Just a little while ago I was thinking of finding or making something like that, but not as good. These are great!

[GasSavers_Erik]

Thanks for posting these!

The most surprising thing for me on the top graph was the friction loss. I expected it to be low at idle and high at full load.

[theholycow]

That isn't surprising because the graph is in percent of fuel energy. That's why BSFC improves closer to full load, and why I prefer low RPM with open throttle.

Also, reciprocating loss is missing, but then the graphs don't deal in RPM.

[koji_kabuto]

this is from early 90's as the tittle "Automotive Fuel Economy: How Far Can We Go?" i have the pdf. i dont have a host for file sharing though. it has some good stuff in it.

[GasSavers_Erik]

Ok, I think I get it now. So if we burn 1 cup of gas in an engine at idle, it will run for quite a long time and it will turn so many rotations that the relatively small frictional losses per crank rotation will be additive and will be very significant.

Whereas if we run a cup of gas through an engine on a dyno at near full load, it will not run very long (fewer revolutions) so the frictional losses add up to less even though they are greater per revolution.

[theholycow]

Seems to be (at least partially) viewable online at
http://books.nap.edu/openbook.php?isbn=0309045304

[theholycow]

The book is at http://www.multiupload.com/FHNOBGOUXQ

[koji_kabuto]

i have a bunch of statistics, CAFE stuff, general.... one could say boring. ill look for the studies and effects of etc etc, i know i have them in my back up hd. in the meantime i give CAFE 2008