I should had mentioned this is for super stock truck pulling.

So its not a lock up converter.

I have a sensor that tells me the tire speed and then i calculate how fast they should have been turning by my gear ratio and just figure out the percentage that way.

Coverter starts to bite at 2000 and is suppose to be a 3500 stall

Every time i do the calculations its between 96 and a few at 98 but it happens. When it is running close to 8000rpm is when i see it closer to 98. At low 7000 it usualy around 96%