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K

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Discussion Starter #1
http://www.turboneticsinc.com/comp_maps/fig16.html


looking at compressor maps, would a near-100% equivalence line indicate the area where the turbo is most efficient?

if not, what the hell do those % numbers mean?

pressure ratio i'm assuming is the charged air pressure / atmospheric pressure, and airflow is obvious.

thanks, just askin out of curiosity
 
K

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Discussion Starter #2
and another question - looking at the compressor map on the given link..

what if you keep pressure ratio constant - say at 2.4, then if you follow the map along that line from the surge limit (dashed line) to the right... for the first part, air flow would actually INCREASE as RPM decreases - doesn't that seem kinda strange? hence, it would make more power at that given boost with a lower RPM? I'm assuming this has something to do with heating of the exiting air...

is that right?
 

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Shawn Davis
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The percent numbers are efficiency. So a 100% efficient turbo would be the ideal case.

Surge limit is on the left of the map (I'm guessing this was just a typo). The RPM listed is of the turbo not the engine. Yes it does seem strange, and yes I think you're right about the the reduction in air flow at higher rpms is due to heating.
 
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Discussion Starter #4
You want to try to get as close as possile to thet center efficiency "island". The rest you can adjust with turbine A/R tuning.

Phil
 
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