the nitto's aren't really that good of a drag radial. my friend had 225/50/16's on his eclipse and he ran just as good with his 18" street tires. with that much WHP look for 12.7-13.0 on those tires. you should get 2.0-2.2 60ft's on those as well. as for blow by I get a bit of white everyonce and a while but that is coolant from what I know, but as you said my coolant level never drops so I don't know. I get black smoke on shifts and at vtec crossover. if you start gettin blue then start worrying