Weber IDF Jetting Options

[FastFroggy]

I am starting to play around with tuning and plan to start getting some small increments in jetting. Just to see if I can improve drivability for now. I have twin 44s

Simple question for now: I need 4 turns of idle mixture to now stumble off the line. Should I consider jetting richer?

thanks

[FastFroggy]

Look I bought the car with this set up and I am trying to learn my way thru it. It runs well and pulls reasonably hard a 2500-6800rpm. After fixing the fuel tank, fuel supply, rebuilding(gaskets) the carbs, fixing the carb weeping, syncing carbs, clutch cables, accelerator cables, installing race seats and belts, I am finally on to engine tuning. I really appreciate the time taken and technical input from all. I am taking it all in.

However the tone I do not appreciate. Thanks for making this a beat on. Quote " If you ignore the repeated advice we're giving here because the changes we're suggesting seem drastic, then you're dragging this process out or you'll never actually get it right." If it continues I'm out.

If this is going to be a technical forum then lets talk data. Weber flow data is limited. What I've found seems wrong for 40mm and 44mm. Calc show about 180-216 cfm: assuming 1800@6800rpm. Does anyone have reliable flow data for Weber IDF's 40 or 44's?

First principles and feedback answered my concern early on. See if i am about right? To overcome my oversized carburators, my overly rich idle adjust may be working on throttle up. However, since there isn't enough air velocity in the carb, it then runs lean once backing off throttle(especially at throttle idle-position) and gives me roll backfire. upsizing the idle jet will not impact backfiring.

BTW, If I were doing it right, I would completely dis –assemble, inspect and build the engine back up. I would compare it to the 5 last race engines I’ve built. I would have build plan to improve on the weaknesses of the past 5 engines. After that I would have my race shop flow bench the carbs, intake, heads and exhaust. Then I would spend a few weeks on the chassis dyno at my race shop with continuous emissions sniffing. None of which I have or have the budget for. Street tuning sucks.

But I'm in the market for a used wideband o2 sensor....