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Re: plenum volume



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  Not sure if this is the right form, but it has to do with my crossfire =
injected project. It seems that a better(more even) distribution and =
better flow would result from moving the top plate/swirl plates away =
from the manifold floor.

  True

   This would also change the plenum volume.

  True

   What part does plenum volume play in the over all scheme of intake =
design?

  Lots, it basically controls what rpm the engine makes peak torque/HP.  =
Also, makes up for flow limits in TB (to a minor degree).

   How will increasing it effect performance, and is there a formula for =
figuring the correct volume for a certain engine combination?

  Varies alot.  Anything from one cylinders volume, to 1.5+x the =
engine's CID.

   I would like to base the changes on something other than physical =
restraints(hood clearance etc.), without having to try a bunch of =
different combos with all the tuning and testing etc involved.

  I have sone extensive porting mods to the cross fire manifold.  Making =
a 1/4" thick spacer for the lid made a large difference (BTW, I'm =
running a 355 CID).  Much better high rpm breathing.
  Also, ground out the ERG tunnel.  Opened up the outside pockets, and =
cut port roofs back 1/8" also.   With enough cam 2" butterflies also =
help.
     BTW run it with a 1227747.  I some wotk but with the info from =
programming 101 makes it real sweet.
  Grumpy

  Kevin R

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  <DIV><FONT size=3D2>Not sure if this is the right form, but it has to =
do with my=20
  crossfire injected project. It seems that a better(more even) =
distribution and=20
  better flow would result from&nbsp;moving the top plate/swirl plates =
away from=20
  the manifold floor.</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>True</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>&nbsp;This would also change the plenum =
volume.</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>True</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>&nbsp;What part does plenum volume play in the =
over all=20
  scheme of intake design?</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>Lots, it basically controls what rpm the engine =
makes peak=20
  torque/HP.&nbsp; Also, makes up for flow limits in TB (to a minor=20
  degree).</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>&nbsp;How will increasing it effect performance, =
and is=20
  there a formula for figuring the correct volume for a certain engine=20
  combination?</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>Varies alot.&nbsp; Anything from one cylinders =
volume, to=20
  1.5+x the engine's CID.</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>&nbsp;I would like to base the changes on =
something other=20
  than physical restraints(hood clearance etc.), without having to try a =
bunch=20
  of different combos with all the tuning and testing etc =
involved.</FONT></DIV>
  <DIV>&nbsp;</DIV>
  <DIV><FONT size=3D2>I have sone extensive porting mods to the cross =
fire=20
  manifold.&nbsp; Making a 1/4" thick spacer for the lid made a large =
difference=20
  (BTW, I'm running a 355 CID).&nbsp; Much better high rpm=20
  breathing.</FONT></DIV>
  <DIV><FONT size=3D2>Also, ground out the ERG tunnel.&nbsp; Opened up =
the outside=20
  pockets, and cut port roofs back 1/8" also.&nbsp;&nbsp; With enough =
cam 2"=20
  butterflies also help.</FONT></DIV>
  <DIV><FONT size=3D2>&nbsp;&nbsp; BTW run it with a 1227747.&nbsp; I =
some wotk=20
  but with the info from programming 101 makes it real =
sweet.</FONT></DIV>
  <DIV><FONT size=3D2>Grumpy</FONT></DIV>
  <DIV>&nbsp;</DIV>
  <DIV><FONT size=3D2>Kevin R</FONT></DIV></BLOCKQUOTE></BODY></HTML>

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