So.... Tried the skinny Venturi mod on the ST .45 setup and it made a huge difference in handling - No other changes required other than a moderate retune which seemed to mostly affect the top end (needed to lean)- The large flat spot the top is now gone and the idle is much improved - The biggest change is tunabiity as the mixture control is no longer critical and very easy to set. I did lose a bit of performance I think but its hard to estimate as it was relatively hot today - I showed 11,300 on a 10/8 today and I think I ran 11,800 or 11,900 on previous occasions (cooler) - I'm going to leave the power "test" to how it feels flying.

I can tell that I will not have to set up overly rich on takeoff with this setup, as was the case before - and I can also tell that tuning will be greatly simplified as there is not a spot in the range that shows critical adjustments any longer.


Here is the comparison of the resulting curve - Without and with Insert.




Previous setup - Big bore

Skinny Venturi