How would a bw 467.7 with a 1.24 t4 housing work? Should spool super fast.

 

Dont think in terms of boost think in terms of air flow. A bigger turbo at the same pressure will move a lot more air than a small turbo. You want to run as much boost as you can, in the 20 to 30 psi range usually, rather than running just a tiny bit of boost. The turbo is a lot happier at higher boost. If you only wanted to run 12 pounds you should have bought a roots blower instead.