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Old 01-28-2009, 01:41 PM   #33 (permalink)
MechEngVT
Mechanical Engineer
 
Join Date: Jun 2008
Location: Richmond, VA
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The Truck - '02 Dodge Ram 1500 SLT Sport
90 day: 13.32 mpg (US)

The Van 2 - '06 Honda Odyssey EX
90 day: 20.56 mpg (US)

GoKart - '14 Hyundai Elantra GT base 6MT
90 day: 30.24 mpg (US)

Godzilla - '21 Ford F350 XL
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Quote:
Originally Posted by wwest40 View Post
Look at it this way...

Using the current implementation of the Atkinson cycle, delayed intake valve closing and 13:1 "native" compression ratio, look at what would happen with just a single cyclinder engine. You would have reverse airflow OUT the intake path/duct for each compression stroke, not exactly viable for a MAF/IAT equipped engine.
I meant to address this in my reply yesterday since IIRC it came up earlier in the thread...but I think christ answers correctly.

This WOULD cause a problem with either an incorrectly designed intake or if you had a single throttle plate per cylinder with no "manifold" per se. In the first situation a proper chamber volume or resonator would buffer the pressure pulses and allow a continuous inflow through the throttle (and therefore the MAF sensor) the way that normal intakes already do this to a lesser degree. In the second situation (one butterfly/cylinder with no resonator) you don't even need a MAF sensor and can map fuel/spark from TPS and RPM.
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