Good luck tryin to get answer to how much spray can i use question. Ive seen many people ask yet never really seen 2 people answer the same thing in a row. The general concensus for nitrous is u take ur HP to the wheels and divide it in half give or take a bit. So an H22 could safely handle a 75 shot, with only timing retard and regapping spark plugs. Dont take my word for it tho.