As centrgfuial chargers are dogshit IMO and dont produce full boost till high rpm, the ONLY way people get em giving good boost at sensible rpm and not hugely overboost at the top end is to do as what people have already touched on, run a simple wastegate or blowoff valve type thing on the inlet piping.

Same as they use on many race cars to stop teams cheating by raising the boost higher than the rules.

Only problem here is your overspeeding it causing the efficiency to drop like a sack of shit, so you will need a good intercooler and/or water injection to keep the charge temps and efficiency in check.

So to sum up, throw it in the bin and use a proper positive dispacment charger