I was spraying my 420a on a 75 shot. All I did was go 3 steps colder on the plugs and retard the timing just a little. The car doesnt run extremely well off the bottle but it runs pretty damn good on the bottle. 420a's tend to take better to nitrous than turbos. When I decide to blow this engine up I'm gonna run a 125 shot with DSM 450's. If it holds then I'll spray that until it decides to blow.