Mike Wills wrote:

  Also note that Tracy flies with 2/3 of the stock TB and as far as I

know

he has never reported a problem with restricted airflow. I'm pretty sure

he

flies with an MP gauge. Not saying it would be a problem to have a larger
TB but apparently there is no penalty for the smaller one like Tracy's on
an NA engine.

Mike Wills

I would not say that. Perhaps Tracy can get some more power. As far
as I know he has never measured the pressure drop across his throttle body.
What ever the MP gage says it might be higher on the other side.
Note the Leman engine had individual slide throttles for each intake
pipe and rotor that are completely out of the way at WOT.

Chuck Dunlap, as I recall has some before and after data but he may have
a large restriction some place else in the system that will mitigate
the effect of a larger TB. Both Perry Mick and George Graham noticed
a HP loss with air filters. I think Perry has some numbers on MP.

Paul Lamar

Paul,
A Little while ago I did check the area of the openings of the Inlet
manifold
compared to the Inlet tubes areas and found the tubes to 18 percent larger
 than the Manifold openings. Now I would assume it would give some leeway
in regard to any pressure drop.
George (down under)

I don't follow you George. 

"openings of the Inlet  manifold " ????


Paul Lamar
 
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