[aerohead]

Luke,I've been thinking about the richening problem on the race car and wanted to toss out the following.---------------------- I found four articles from HOT ROD Magazine dealing with mixture issues which went in a direction I would not have thought.------------------ The racers were experiencing water pump cavitation which led to uneven combustion chamber temperatures,which played hell with mixtures.--------------- Their solution was to use old-tech cast-iron impellers,with more efficient hydrodynamic vanes instead of stamped-steel impellers.----------- Sometimes they used smaller diameter pumps to reduce angular velocities at the vane tips,and lastly,they might under-drive the pump a bit to keep speeds below what would cause cavitation.------------------- The modern electrically-driven pumps may do away with these issues,don't know.----------------------------------------------------------------- The other thing I noticed is that the flat-faced driven pulley of the blower,and brackets behind it,near the bug-catcher,look like they could actually interfere with airflow into the throttles,and lastly,the throttles on some bug-catchers have virtually no radii at all ahead of the openings,just a sharp-edged corner.----------------------------------------- All elementary fluid dynamics textbooks would say this was a no-no,and lead to what they call a "vena-contrata" entry loss,where the air cannot flow anywhere near the walls of the opening due to flow separation at the inlet,effectively squeezing down the flow at a point where you need it the most.--------------------- If you have this,not only will you have an immediate flow restriction,you also raise the power necessary to impel the air into the blower which will add heat to the compressor,expanding the charge,and requiring a leaning of the fuel supply to maintain stoiciometrics.------------------------------------------------------- I can't tell as much as I'd like from the photos of the car and your hardware may be better evolved than others,but if the problem with the mixture persists you might consider a second look there at the inlet.Best to you,Phil.