Racing Fuel Systems

An update. Living in southern Ontario Canada the daytime temp has dropped to 15 celsius ( 59 degrees fahrenheit ) . The carb has developed a slight hesitation.

So I got the car out as the weather got good.
Over the winter I made some changes to address the slight hesitation at cruise speed, after switching to annular boosters in the primary side.
The weather had turned bad last fall , so I wasn’t able to go any further.

I tried removing the TSR to see how much effect it was having. It was a lot. Cruise AFR went to around 13.5:1 and hesitation was still there.

Next Changes:
PMJ #62 to # 61
Primary IAB .077 to .074
TSR .064 to .062
Primary PV 6.5 to 10.5

I have driven on a cool 14 celsius morning and a 26 celsius afternoon . The hesitation at cruise speed is gone. The changes were small .
Cruise AFR is now hovering at 15:1 . Throttle response is very good.

Any idea/data on the difference in signal between those skinny 4180 inserts and standard .600" inserts?

They are inserts, right? In a standard banjo?

These are a one piece Booster/banjo's . Inside smallest diameter is .650". Exit at lower of banjo inside diameter is .900". These are .750" tall. Leg has a .190" entrance which reduces to .160 inside diameter.
8 exit holes approx .072"

How was the internal annular ring machined if they are one piece with no insert? 3D-printed zinc? Nibbled out one atom at a time after casting by nanobots?

Well I didn't get that right. Yes they are two piece , top and bottom pressed together. But not really an in insert. I'll post a picture later.

The arrows show the parting lines.