Hi Paul,

 Is the volume of the plenum chamber on a throttle body/plenum setup
critical in any way ?

Cheers Chris in NZ

It has something to do with it. Technically it is called a
Helmholtz resonator.


Paul Lamar



Hi Paul,
 Thanks for all that, very helpful, I don't know
what I'd do without all this help and
info from your newsletter, I might have been reduced to
 (dare I say it) putting in a
piston engine !
  Cheers Chris in NZ.



Chris,
This explains it pretty well.
Paul Lennemann

Does all the theory on Paul Lennemann's induction design attachment apply
apples to apples with rotary's as well as pistons? Or what would the
differences (if any) be.

Alex M

  The difference  is the ports on a rotary never close for long periods of
  time. As one chamber is filling another is right behind. Same goes for the
  exhaust.

  On a one cylinder the intake and exhaust are  closed 3/4 of the
  time. The rotary is a mix of turbo jet and electric motor :)

  Paul Lamar

thanks, got it,

Alex

Hi Paul,
    I understand the differences between the rotary and piston engines. Do the formulas for the Helmholtz resonator (which seem to apply to piston engines) work for a rotary ? are they the same ?
        Chris.

The resonator works the same but it depends on where and how in the system it is applied. You can have a HR with x number of intake pipes
entering and exiting. The more pipes the higher the frequency the HR is tunned for. The 2 rotor is equal to a 4 cylinder four cycle in frequency of firing but the pattern of the pulses in the intake tubes is different.

The waves in a p-port intake are perfect sine waves but those in a piston engine is one pulse every two revolutions with dead space in between.

Paul Lamar