Aisin secondary tuning ideas (1 Viewer)

[greenEFSI]

I don't have a pic of my actual carb, but I was referring to this tang circled. I bent it to barely touch and close the gap.

 

[Skreddy]

Another possibility:

If the choke is not engaged, then you’re getting a ton of air flow from a cold carb into a cold intake and the fuel isn’t atomizing very well. Lots of air, and lots of big, liquid fuel droplets. That might lead to a crappy burn in the cylinder. Just a guess, as what happens inside the cylinders is still black magic to me - ignition, flame fronts, squish, etc., are all pretty technical and mysterious subjects to me.

And yes, perhaps the vacuum is enough to hold the secondary blade open even if the mechanical opening retracts a bit. Good call.

My cold take offs are definitely better with bending that tab, whatever the reason. I am running 3FE manifolds as well so no heat from the exhaust to warm up the intake. My cold takeoffs got worse when I went to these manifolds a couple months ago and is back to normal after bending that tab.

I can feel the engagement of the secondary through the pedal as there’s additional spring resistance on the secondary blade. Was trying different pedal positions and scenarios driving home this morning and this bend already made a huge difference. My rpm’s increase much faster in 1st through 3rd gears from about 1800 up to 3500 rpm. It gets up to “around town” speed much faster from a stop now.

Thanks again for chronicling the basics and getting me curious!

 

[CruiserTrash]

My cold take offs are definitely better with bending that tab, whatever the reason. I am running 3FE manifolds as well so no heat from the exhaust to warm up the intake. My cold takeoffs got worse when I went to these manifolds a couple months ago and is back to normal after bending that tab.

I can feel the engagement of the secondary through the pedal as there’s additional spring resistance on the secondary blade. Was trying different pedal positions and scenarios driving home this morning and this bend already made a huge difference. My rpm’s increase much faster in 1st through 3rd gears from about 1800 up to 3500 rpm. It gets up to “around town” speed much faster from a stop now.

Thanks again for chronicling the basics and getting me curious!

That’s close to what I’m feeling. I took up the “slack” in that tab you circled. That combined with moving the other tab (first touch) makes it feel like there’s more juice starting at around 1800 rpm. It’s been nice for congested city driving.