you can pretty much run the 75 shot without any worries, but may not get the maximum out of it. my car on the other hand gained nearly a a whole second on just a 75 shot. anything more than that you need to retard the timing. I at least had a pressure gauge to make sure I had acceptable pressure before I sprayed mine. temperature of the bottle plays a big part in that and you can always use alternative ways to heat or cool the bottle if needed. the only place I spray mine is at the track anyways so regulating that isnt hard for me, just not as convenient.