My 2-step is triggered off the brake pedal. I have it set at 3000 and it hits the tires hard but my 60's suffer due to the short wheelbase and the (too) high rate of wheelstand. If I understand what Lenny said the higher the launch speed the less violent a light car will hit the tires. Like I said it seems counter intuitive but since you are at WOT you get no torque boost from the (secondary) pump shot.

So....I was going to try 3800 and if that helps, 4200 on a 5300 flash, brake pedal is plenty stout to keep it from rolling through at 3000.

Still hoping Lenny will chime in, I may just need to call him. Again, I'm trying to visualize the fluid dynamics of the converter in those first couple 1/10's of a second after coming off the footbrake.

It's logical that generally the lighter a car is the "tighter" a given converter will be for a given gear (torque multiplication) and the hit would be a bit softer, just trying to get my head around the FB RPM vs launch RPM vs true Flash (full pull)