450 BHP upgrade?? Have you heard something we haven't....(always assumed 430 was max on that engine) The Emira at 450 BHP would be a pretty special.
Komotec has "power phases" or packages that take the Evora up to 460-475HP and consist of carbon intake, ss exhaust, o2 spacer (to clear CEL), and their tune. The engine can take a lot more, but the manual gearbox is the weak point. I've been keeping an eye on their Emira power phases page. There is a "EM-475" placeholder that should be similar to their EV4-475 package for the Evora (see chart below). Hopefully we'll get some info soon!