My car is powered by a 1977 2.4 Pinto motor. 3 speed auto. It has the Holley twin choke carb. Several years ago I put the secondary main jet in the primary and with a jet drill opened the jet i put in the secondary choke. A decent improvement straight away. Since then I have been shimming the linkage so that the secondary butterfly opens earlier.
It is supposed to open when the primary opens when it is at 45 degrees. I have it opening earlier and what a difference in pickup! This happens from lows revs all the way through! At low throttle openings/cruising speeds the secondary is still closed but when I put my foot down the secondary kicks in and the car accelerates so much better. This happens without the trans. changing from high gear. Big difference at even 2000 rpm in high gear. Probably uses more gas but the car is not my daily driver!
Fred