Nitrous on Stock motor
nitrous doesnt kill motors,lean conditions do(not enough fuel).a 150-shot is ok to do on a stock internal motor.granted you do it RIGHT.new plugs(TR6),FPSS(fuel pressure safety switch),window switch(for an M6),and proper maintenance.oh yeah, most companies highly recommend, if you run a 150-shot, do a new 255lph walbro fuel pump. good luck.
I have 100 Wet shot, from Coldfusion nitrous kits. I think I will up it to 125 shot. Havent had any problems, motors running fine. I have it connected through the smooth air bellow, but I'm going to drill the TB tonight and mount the nozzle correctly. The only downside is Coldfusion supplys "SHORT" lines from solenoids to shark nozzle.

