At what rpm do you guys launch with BFG dragradials on a turbo B16 or 18?

I'm launching @ 6k with a turbo b16 my best 60ft is 2.1

I've seen that some guys are hitting 1.9 etc with these tires

I'm doing the burnout, open differential, tirepressure was about 12 psi.

What do you guys suggest

 

i was launching between 4500-5000 rpm, trying to keep it closer to 4500. ridng the clutch off the line i was able to get consistant 1.96-1.98 60' times with a type r tranmission after that it was just wheel spin till 3rd. i was also running 12psi. i heard people going lower with the air pressure but the season was over so i didnt get a chance to play around with less air.