Common plenum or individual runners???, for gas milage and drivability |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Common plenum or individual runners???, for gas milage and drivability |
Mueller |
Dec 16 2004, 10:04 PM
Post
#101
|
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.... |
lapuwali |
Jan 20 2005, 08:21 PM
Post
#102
|
||
Not another one! Group: Benefactors Posts: 4,526 Joined: 1-March 04 From: San Mateo, CA Member No.: 1,743 |
The sizing of carbs has the additon of fuel metering, true, but pure airflow is all I'm discussing here. The venturi is going to limit the amount of airflow into the engine, regardless of whether there's fuel getting sucked through a jet or pumped through an injector. The max. power of the engine is basically limited by how much air it can ingest. If an engine can make 150hp with 36mm carb venturis (one per cylinder), then it's also going to be able to make 150hp with a sufficiently large plenum fed by a 36mm TB, since the TB will flow as much air as the venturi in the each carb. The exact reasons why a 36mm venturi would be chosen in a carb are clear, given the need for good intake velocity past the jets. Why TB sizes are chosen as they are is, frankly, still a mystery to me. They all seem to be too big, even the 45mm unit on the stock 2.0. |
||