hey geoff, i know you like the 40mm better than the 46mm? how come what's the difference in design that makes the 40 better than the 46? also would anyone know what the 40mm is rated hp wise?

 

I've personally seen a 40mm Tial hold 20+psi just fine and make 400+whp on the dyno. I would think it's good to hold 2bar reliably with a good boost controller and using a moderately stiff spring in comparision to your max boost level.