NOS setups are a lot of fun in this game. I love the blue exhaust flames :P . Your tune could use a little love. Set all NOS stages to engage in 1st gear. 1st and 2nd stage set to 1000 rpm, 3rd set to 2000 and 4th set to 2200. As far as suspension, right now the meta is to slam the thing on the softest springs with max bump/rebound. Shift your weight to the front, like .6 and lower it to 0.4. With this setup you shouldnt need the wheelie bars. Set launch rpm to 8500 and shift at 9600. You also definitely want to spend the gold on the perfect tunes. Gearing you can mess around with but start with this: 1st 3.90, 2nd 2.70, 3rd 2.16, 4th 1.78, 5th 1.50, 6th 1.29, final 2.90. You'd do better with a pro charger which could get you to 5.6-5.7, with a great launch and perfect shifting of course. Using the delay box can help a lot also. I usually set mine to like .300 and release the launch button when i see the 3rd yellow. You also want to go with the widest tires, unless you're running the 10.5 races. With the setup above, you should easily be able to get low 6's and with some practice should be able to get into the 5's. Its interesting that you got the Camaro as your member car. I got the TrackHawk. Thought everyone got the same one but clearly not.
You can do more upgrades on the Camaro and its all free and I recommend fully maxing out the spark plugs and distributor and valve train because they are really cheap and help hp alot