Common plenum or individual runners???, for gas milage and drivability |
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Common plenum or individual runners???, for gas milage and drivability |
Mueller |
Dec 16 2004, 10:04 PM
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#101
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
for my 2316 it seems that the stock plenum might be reaching it's limits as far as volume goes.....so, I either fabricate a larger common plenum, or go with individual throttle bodies such as TWM or Jenvey*
single plenum would be easiest, but the individual throttle bodies look better (IMG:style_emoticons/default/smile.gif) has anyone switched from one to the other on the same motor with everything else being the same??? *Jake Raby is the U.S. distributor of these.... |
Bleyseng |
Jan 20 2005, 07:35 PM
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#102
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Aircooled Baby! Group: Members Posts: 13,035 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
Well, you are mixing apples and oranges since carb vents and TB's have little in common. The venturi is where the fuel is mixed and you must achieve proper atomization. The TB is a air metering device sized by the air charge needs.
Dual TB's suffer from poor driveablity and tuning but a great for drag racing where they are tuned for one basic rpm (WOT). The plenum and runners FI is a different concept than dual carbs. Since the intake air doesnt have to hold fuel in it and the fuel is delivered smack on the valve, its more tuneable. The runners are sized to hold atleast one chambers volume for an intake stroke. The plenum holds the recharge air plus additional as there is overlap from other cylinders. How the engineers calculate this with math is beyond me. I am hoping out resident math wiz has figured it out! Geoff |