Quote: [is your enemy for efficiency. <snip> Care to explain what this means??? For many years vacuum gauges were mounted in cars & labeled as an "Economy Meter" & you seem to feel vacuum is bad??? Please explain...
One of the 3 main reasons that diesels get better MPG is the lack of a throttle = almost no vacuum, lots less pumping losses.
(The other 2 are higher CR and more BTUs per gallon of fuel).
Back to the Imp: Will this be carb's or SMPI? (I hope it is the latter).
Rick
Just about one of the only completely correct posts in this thread, thanks Rick.
Feets you have your answer, the lower the better.
If you were building a high strung N/A motor with 12:1 and a long duration (like 265@.050 and greater) tight LSA cam, I'd say ya maybe you don't want to go below 1800 or so (depends on cubes and cam) but considering it's a turbo build with a really mild cam, go as low as you want.
I'm sure you'll hit your personal gear ratio limit on acceleration before it's too low for the motor.
Care to explain what this means??? For many years vacuum gauges were mounted in cars & labeled as an "Economy Meter" & you seem to feel vacuum is bad??? Please explain... 
