OK, this is my experience with converters, the more power you make the higher the stall/flash, and Roger is mostly right , the higher you shift to a point the higher the flash [ what the RPM drops to right after the shift].
So the power can be affected by weather, tune-up ,and changes in your combo. After any combo changes I check my converter flash, also the looser [ higher flash] the converter the more it will show slippage, unless you step-up to a lock-up type converter, and that means it will slip less not really lock-up. With a lock-up it will pull the RPM down in the middle so the suggestion is to go to more gear.
My numbers in 2018 ; highest shift 10430 rpm, flashing at 8773 rpm, with 5.7 slippage at DA 1807', lowest shift was 9672 flash at 8624, slip at 5.6% at 1566 DA, running 7.03 @186 mph
At a hot event [ lower HP] 10137 shift flash at 8528 at DA 4000' and 102° air, and 7% slippage.
I prefer we shift more like 9700-9800 rpm, flashing at 86-8700 rpm , I just bought a looser converter because I want to try 8800-8900 flash.
I can share more real numbers if anyone wants, but I hope this helps clear-up any confusion.
Again our car is a JRFuel "B" all iron SBC on pure alky , PG on 12" wide tires weighing 1435 with driver.
Jon
