I’m planning on putting a smaller pulley on the V6 VT with a stock L67 engine. I’m just after some information on how much psi I can put into my motor before it starts doing damage or my supercharger spins to fast and doesn't work?

On a stock motor we recommend a maximum of 10psi with 98ron fuel and the factorytune. However, considering you intend to fit a cam you will need a custom tune, in that case you will be able to run a slightly smaller pulley due to the increased efficiency of the motor. In conjuction with the factory tune and no intercooling using 98 octane the max is a 10 psi pulley. If you be using a custom tune you can go to? If you choose to go down the intercooler route it will depend on the size and type W2A or A2A. Other options to consider would be fitting our high ratio rockers instead of a cam as this can be done without a custom tune. Another option if you are after greater power gains would be to consider a W2A (water 2 air) intercooler kit as this will also allow you to run more boost without needing a custom tune.