I have 30 runs on 14x42 phoenix d9 slicks on a 12 inch rim with tubes.The outer 2 inches of both tires appear unused.At 7 lbs.of air they still look rounded, is this normal? I removed the tubes ,7 lbs per side and now the tires look squared at 12 lbs,so do you run more pressure wo tubes? My best 60 ft is 1.36 ans very consistent 1.38 but i think i should in the 1.32range,going racing this weekend trying to figure out initial tire pressure .car is 3050 lbs 52/48 fr/r ladder bar,leaves well and goes straight, best et 9.74 136.7 all runs so far on marginal tracks,am i correct about the 60 being weak?does tube removal improve et or hook or not? thanks for any advise

You need wider wheels. Removing the tubes will allow the tread area to lay flatter and is why a lot of people don't use them. You will give up a little stability and you may be putting more air in them than with the tubes.

The bigger the tire the less air you need to make them work. Try 7 lbs at the track tubeless and then go up 1/2 lb at a time until they start to spin, then go down 1/2 to 1.0 lbs and run that