your car will shut down at about 12-15 lbs of boost with the factor y boost guage connected if you undo it it will not cut out anymore you can adjust your wastegate actuator on the turbo you can find out how easily if you do leave your factory boost guage +connected+ then turn the actuator up until it shuts off when you floor it then just back it down until it doesnt do it any more
you want to use premium gas if you plan on more boost than that you will have to use racing gas but you can find that in the phone book i ran 15lbs with the tune that i had on my car but anything more i needed the race gas that was also without my factory boost
guage hooked up. do not be fooled by expensive vacuum restricting boost controlers and get and air fuel meter and figure out how to use it .... good luck