Hello (again).


I still lurking in the background learning a great deal.  You gentlemen have a great deal of knowledge.  I have a few quick questions which I'm a little embarrassed to ask, as I sure they have been
addressed before I joined the group.  Both questions are about the intake.  I attempting to install my 89 turbo II motor (less the turbo now) on an Osprey II.  An entirely new engine pod will have
to be built, so I could use the stock intake manifold, but I really would like to lose the 5 extra inches of drag the stock manifold would create in the pod.  I'm leaning toward a manifold design
like Bulent Aliev built.  My questions are: 1)  Will some kind of ram air really make that much difference? 2)  Why does it not look like anyone is trying to incorporate any kind of dynamic chamber
in the designs?  Sorry if these questions have already been asked, I'm new and learning.

Thanks

Gregg Miley

Basically the controversial dynamic chamber was an invention by Mazda to do double
duty. It was/is tuned at two RPM points. The second one is twice the first.
For example if you tune the dynamic chamber for 3000 RPM and max torque it will
also be tuned for 6000 RPM. The RX8 uses the same idea but there are three stages.
2500, 5000 and 7500 RPM roughly. Absolutely essential for a NA rotary powered car.

In an aircraft engine there is only one RPM that counts or a small range of RPM
that counts. Namely about a 1000 RPM range where the prop load is a maximum. The
range can be 6000 to 7500 RPM between static takeoff RPM and maximum speed RPM
with a fixed pitch prop. A constant speed prop will broaden the range somewhat
but not as much as a 2:1 range such as the dynamic chamber provides. The BSFC
of the engine is also minimum at the RPM point of max torque.

Tracy Crook also recently verified this fact by his new intake manifold that
is tuned to one RPM. He is taking off the same and going as fast as his old dynamic
chamber intake manifold. Other people have tried to use the Mazda dynamic chamber
tuning with less than notable results.

Now having said all that there is a minor pulse reflection from
rotor intake to rotor intake but so far nobody has tuned a dynamic chamber
short enough to work at 6000 let along 7000 RPM. Here are a few
ideas of mine on this subject.

Paul Lamar

Wow,
Thanks for the fast reply.
Sounds too complicated for my simple machining and welding capibility.  If the results are hit and miss, I guess I'll be sticking to something simpler to build.  Aside from height and weight
issues, any reason not to use the stock turbo intake and throttle body?  How about the ram air?  Much hp gain?  I really wanted the leave the engine stock, but I'm starting to wonder how much HP I
will end up with.  Any ideas?

Thanks again for all the information.

Gregg

Height and weight. P-port manifold you are looking at 220 HP or so.

Please forward quote your replies Gregg. Helps people follow the thread.

Paul Lamar
 
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