Intake runner lengths

[Stuart Bunning]

Just to add to this topic. My application is to only have one set of
injectors The 2nd butterfly's and runners which is not visible from the
outside simply blocks the shorter path inside the manifold. So when I hit
about 4500RPM the internal butterfly inside the manifold opens giving the
air a short cut to the motor instead of having to do a loop inside the
manifold. If anyone outside of AUstralia has seem one of the late model
DAEWOO larnos's I think ?? although 4 cylinder they have this dual runner or
dual ressonance manifold's on them they kind of look like a 4 snails or in
my case as i am using ford 6cyl EF/EL manifold 6 s snails.

So what am i asking, after all this rambling on ??
Well if I use this approach. I will get more torque down low or up high
depends how you look at it compared to using a standed fixed length manifold
So do i have to adjuct my fuel map when the runners change length or is this
one of those "FREE POWER" modifications that will give me more torque for
FREE  without adding extra fuel just because the runners are longer ????



At 09:38 PM 13/12/98 -0500, you wrote:
>There is only one system I know of using the 2nd Butterfly/runners,
>and in that system them turn on a second set of injectors, the
>secondary injectors run at the same duty cycle as the primary.
>BTW, on that system the sec buttterfly was operated by a vac.
>diapharm.  While seemingly crude it was what the ZR-1 vettes
>used
>Bruce
>
>


Best Regards,

STUART BUNNING
SALES ENGINEER
KENELEC PTY LTD

23-25 REDLAND DRIVE
MITCHAM VICTORIA 3132
AUSTRALIA

PHONE:  61 3 9873 1022
FAX:    61 3 9873 0200
EMAIL:  stuart at kenelec.com.au
WEB:    http://www.kenelec.com.au/