Having an issue with car downshifting into second from a 40-45 roll. I am assuming ti's tuning related but want to try and figure out exactly what needs to be adjusted. I went from a tighter 3600 to a loose 4000. It's a prostreetautomatics 4l65e. If i hit it from 40-45 the car will go to downshift but then just bang the limiter. If I hit it from 50 the car will drop into 2nd and take off fine.
What is the exact issue I am having, the car trying to reach for first? Never did this with the old setup, but now it's a new stall and some more power.

Thanks!

 

you need to scan it and see what it's doing.
The 60e with its wide ratios can have agressive downshifts.
See which gear is being commanded and go from there.

 

Ditto ^^^
Your loose converter is allowing more engine RPM per MPH. You likely need to tune your shift tables.